tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
/*
|
|
|
|
|
* trace_events_hist - trace event hist triggers
|
|
|
|
|
*
|
|
|
|
|
* This program is free software; you can redistribute it and/or modify
|
|
|
|
|
* it under the terms of the GNU General Public License as published by
|
|
|
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
|
|
|
* (at your option) any later version.
|
|
|
|
|
*
|
|
|
|
|
* This program is distributed in the hope that it will be useful,
|
|
|
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
|
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
|
|
|
* GNU General Public License for more details.
|
|
|
|
|
*
|
|
|
|
|
* Copyright (C) 2015 Tom Zanussi <tom.zanussi@linux.intel.com>
|
|
|
|
|
*/
|
|
|
|
|
|
|
|
|
|
#include <linux/module.h>
|
|
|
|
|
#include <linux/kallsyms.h>
|
|
|
|
|
#include <linux/mutex.h>
|
|
|
|
|
#include <linux/slab.h>
|
|
|
|
|
#include <linux/stacktrace.h>
|
2017-02-04 08:27:20 +08:00
|
|
|
#include <linux/rculist.h>
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:51:58 +08:00
|
|
|
#include <linux/tracefs.h>
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
|
|
|
|
|
#include "tracing_map.h"
|
|
|
|
|
#include "trace.h"
|
|
|
|
|
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:51:58 +08:00
|
|
|
#define SYNTH_SYSTEM "synthetic"
|
|
|
|
|
#define SYNTH_FIELDS_MAX 16
|
|
|
|
|
|
|
|
|
|
#define STR_VAR_LEN_MAX 32 /* must be multiple of sizeof(u64) */
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
struct hist_field;
|
|
|
|
|
|
2018-01-16 10:51:54 +08:00
|
|
|
typedef u64 (*hist_field_fn_t) (struct hist_field *field,
|
|
|
|
|
struct tracing_map_elt *elt,
|
|
|
|
|
struct ring_buffer_event *rbe,
|
|
|
|
|
void *event);
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
|
2017-09-23 03:58:23 +08:00
|
|
|
#define HIST_FIELD_OPERANDS_MAX 2
|
2018-01-16 10:51:49 +08:00
|
|
|
#define HIST_FIELDS_MAX (TRACING_MAP_FIELDS_MAX + TRACING_MAP_VARS_MAX)
|
2018-01-16 10:51:57 +08:00
|
|
|
#define HIST_ACTIONS_MAX 8
|
2018-01-16 10:51:49 +08:00
|
|
|
|
2018-01-16 10:51:52 +08:00
|
|
|
enum field_op_id {
|
|
|
|
|
FIELD_OP_NONE,
|
|
|
|
|
FIELD_OP_PLUS,
|
|
|
|
|
FIELD_OP_MINUS,
|
|
|
|
|
FIELD_OP_UNARY_MINUS,
|
|
|
|
|
};
|
|
|
|
|
|
2018-01-16 10:51:49 +08:00
|
|
|
struct hist_var {
|
|
|
|
|
char *name;
|
|
|
|
|
struct hist_trigger_data *hist_data;
|
|
|
|
|
unsigned int idx;
|
|
|
|
|
};
|
2017-09-23 03:58:23 +08:00
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
struct hist_field {
|
|
|
|
|
struct ftrace_event_field *field;
|
|
|
|
|
unsigned long flags;
|
|
|
|
|
hist_field_fn_t fn;
|
|
|
|
|
unsigned int size;
|
2016-03-04 02:54:44 +08:00
|
|
|
unsigned int offset;
|
2017-09-23 03:58:23 +08:00
|
|
|
unsigned int is_signed;
|
2018-01-16 10:51:55 +08:00
|
|
|
const char *type;
|
2017-09-23 03:58:23 +08:00
|
|
|
struct hist_field *operands[HIST_FIELD_OPERANDS_MAX];
|
2018-01-16 10:51:47 +08:00
|
|
|
struct hist_trigger_data *hist_data;
|
2018-01-16 10:51:49 +08:00
|
|
|
struct hist_var var;
|
2018-01-16 10:51:52 +08:00
|
|
|
enum field_op_id operator;
|
2018-01-16 10:51:56 +08:00
|
|
|
char *system;
|
|
|
|
|
char *event_name;
|
2018-01-16 10:51:52 +08:00
|
|
|
char *name;
|
2018-01-16 10:51:56 +08:00
|
|
|
unsigned int var_idx;
|
|
|
|
|
unsigned int var_ref_idx;
|
|
|
|
|
bool read_once;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
};
|
|
|
|
|
|
2018-01-16 10:51:54 +08:00
|
|
|
static u64 hist_field_none(struct hist_field *field,
|
|
|
|
|
struct tracing_map_elt *elt,
|
|
|
|
|
struct ring_buffer_event *rbe,
|
|
|
|
|
void *event)
|
2016-03-04 02:54:52 +08:00
|
|
|
{
|
|
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:51:54 +08:00
|
|
|
static u64 hist_field_counter(struct hist_field *field,
|
|
|
|
|
struct tracing_map_elt *elt,
|
|
|
|
|
struct ring_buffer_event *rbe,
|
|
|
|
|
void *event)
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
{
|
|
|
|
|
return 1;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:51:54 +08:00
|
|
|
static u64 hist_field_string(struct hist_field *hist_field,
|
|
|
|
|
struct tracing_map_elt *elt,
|
|
|
|
|
struct ring_buffer_event *rbe,
|
|
|
|
|
void *event)
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
{
|
|
|
|
|
char *addr = (char *)(event + hist_field->field->offset);
|
|
|
|
|
|
|
|
|
|
return (u64)(unsigned long)addr;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:51:54 +08:00
|
|
|
static u64 hist_field_dynstring(struct hist_field *hist_field,
|
|
|
|
|
struct tracing_map_elt *elt,
|
|
|
|
|
struct ring_buffer_event *rbe,
|
|
|
|
|
void *event)
|
2016-03-04 02:54:53 +08:00
|
|
|
{
|
|
|
|
|
u32 str_item = *(u32 *)(event + hist_field->field->offset);
|
|
|
|
|
int str_loc = str_item & 0xffff;
|
|
|
|
|
char *addr = (char *)(event + str_loc);
|
|
|
|
|
|
|
|
|
|
return (u64)(unsigned long)addr;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:51:54 +08:00
|
|
|
static u64 hist_field_pstring(struct hist_field *hist_field,
|
|
|
|
|
struct tracing_map_elt *elt,
|
|
|
|
|
struct ring_buffer_event *rbe,
|
|
|
|
|
void *event)
|
2016-03-04 02:54:53 +08:00
|
|
|
{
|
|
|
|
|
char **addr = (char **)(event + hist_field->field->offset);
|
|
|
|
|
|
|
|
|
|
return (u64)(unsigned long)*addr;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:51:54 +08:00
|
|
|
static u64 hist_field_log2(struct hist_field *hist_field,
|
|
|
|
|
struct tracing_map_elt *elt,
|
|
|
|
|
struct ring_buffer_event *rbe,
|
|
|
|
|
void *event)
|
2016-03-04 02:55:02 +08:00
|
|
|
{
|
2017-09-23 03:58:23 +08:00
|
|
|
struct hist_field *operand = hist_field->operands[0];
|
|
|
|
|
|
2018-01-16 10:51:54 +08:00
|
|
|
u64 val = operand->fn(operand, elt, rbe, event);
|
2016-03-04 02:55:02 +08:00
|
|
|
|
|
|
|
|
return (u64) ilog2(roundup_pow_of_two(val));
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:51:54 +08:00
|
|
|
static u64 hist_field_plus(struct hist_field *hist_field,
|
|
|
|
|
struct tracing_map_elt *elt,
|
|
|
|
|
struct ring_buffer_event *rbe,
|
|
|
|
|
void *event)
|
2018-01-16 10:51:52 +08:00
|
|
|
{
|
|
|
|
|
struct hist_field *operand1 = hist_field->operands[0];
|
|
|
|
|
struct hist_field *operand2 = hist_field->operands[1];
|
|
|
|
|
|
2018-01-16 10:51:54 +08:00
|
|
|
u64 val1 = operand1->fn(operand1, elt, rbe, event);
|
|
|
|
|
u64 val2 = operand2->fn(operand2, elt, rbe, event);
|
2018-01-16 10:51:52 +08:00
|
|
|
|
|
|
|
|
return val1 + val2;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:51:54 +08:00
|
|
|
static u64 hist_field_minus(struct hist_field *hist_field,
|
|
|
|
|
struct tracing_map_elt *elt,
|
|
|
|
|
struct ring_buffer_event *rbe,
|
|
|
|
|
void *event)
|
2018-01-16 10:51:52 +08:00
|
|
|
{
|
|
|
|
|
struct hist_field *operand1 = hist_field->operands[0];
|
|
|
|
|
struct hist_field *operand2 = hist_field->operands[1];
|
|
|
|
|
|
2018-01-16 10:51:54 +08:00
|
|
|
u64 val1 = operand1->fn(operand1, elt, rbe, event);
|
|
|
|
|
u64 val2 = operand2->fn(operand2, elt, rbe, event);
|
2018-01-16 10:51:52 +08:00
|
|
|
|
|
|
|
|
return val1 - val2;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:51:54 +08:00
|
|
|
static u64 hist_field_unary_minus(struct hist_field *hist_field,
|
|
|
|
|
struct tracing_map_elt *elt,
|
|
|
|
|
struct ring_buffer_event *rbe,
|
|
|
|
|
void *event)
|
2018-01-16 10:51:52 +08:00
|
|
|
{
|
|
|
|
|
struct hist_field *operand = hist_field->operands[0];
|
|
|
|
|
|
2018-01-16 10:51:54 +08:00
|
|
|
s64 sval = (s64)operand->fn(operand, elt, rbe, event);
|
2018-01-16 10:51:52 +08:00
|
|
|
u64 val = (u64)-sval;
|
|
|
|
|
|
|
|
|
|
return val;
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
#define DEFINE_HIST_FIELD_FN(type) \
|
2018-01-16 10:51:43 +08:00
|
|
|
static u64 hist_field_##type(struct hist_field *hist_field, \
|
2018-01-16 10:51:54 +08:00
|
|
|
struct tracing_map_elt *elt, \
|
|
|
|
|
struct ring_buffer_event *rbe, \
|
|
|
|
|
void *event) \
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
{ \
|
|
|
|
|
type *addr = (type *)(event + hist_field->field->offset); \
|
|
|
|
|
\
|
2016-03-04 02:54:53 +08:00
|
|
|
return (u64)(unsigned long)*addr; \
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
DEFINE_HIST_FIELD_FN(s64);
|
|
|
|
|
DEFINE_HIST_FIELD_FN(u64);
|
|
|
|
|
DEFINE_HIST_FIELD_FN(s32);
|
|
|
|
|
DEFINE_HIST_FIELD_FN(u32);
|
|
|
|
|
DEFINE_HIST_FIELD_FN(s16);
|
|
|
|
|
DEFINE_HIST_FIELD_FN(u16);
|
|
|
|
|
DEFINE_HIST_FIELD_FN(s8);
|
|
|
|
|
DEFINE_HIST_FIELD_FN(u8);
|
|
|
|
|
|
|
|
|
|
#define for_each_hist_field(i, hist_data) \
|
|
|
|
|
for ((i) = 0; (i) < (hist_data)->n_fields; (i)++)
|
|
|
|
|
|
|
|
|
|
#define for_each_hist_val_field(i, hist_data) \
|
|
|
|
|
for ((i) = 0; (i) < (hist_data)->n_vals; (i)++)
|
|
|
|
|
|
|
|
|
|
#define for_each_hist_key_field(i, hist_data) \
|
|
|
|
|
for ((i) = (hist_data)->n_vals; (i) < (hist_data)->n_fields; (i)++)
|
|
|
|
|
|
2016-03-04 02:54:52 +08:00
|
|
|
#define HIST_STACKTRACE_DEPTH 16
|
|
|
|
|
#define HIST_STACKTRACE_SIZE (HIST_STACKTRACE_DEPTH * sizeof(unsigned long))
|
|
|
|
|
#define HIST_STACKTRACE_SKIP 5
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
#define HITCOUNT_IDX 0
|
2016-03-04 02:54:52 +08:00
|
|
|
#define HIST_KEY_SIZE_MAX (MAX_FILTER_STR_VAL + HIST_STACKTRACE_SIZE)
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
|
|
|
|
|
enum hist_field_flags {
|
2017-09-23 03:58:21 +08:00
|
|
|
HIST_FIELD_FL_HITCOUNT = 1 << 0,
|
|
|
|
|
HIST_FIELD_FL_KEY = 1 << 1,
|
|
|
|
|
HIST_FIELD_FL_STRING = 1 << 2,
|
|
|
|
|
HIST_FIELD_FL_HEX = 1 << 3,
|
|
|
|
|
HIST_FIELD_FL_SYM = 1 << 4,
|
|
|
|
|
HIST_FIELD_FL_SYM_OFFSET = 1 << 5,
|
|
|
|
|
HIST_FIELD_FL_EXECNAME = 1 << 6,
|
|
|
|
|
HIST_FIELD_FL_SYSCALL = 1 << 7,
|
|
|
|
|
HIST_FIELD_FL_STACKTRACE = 1 << 8,
|
|
|
|
|
HIST_FIELD_FL_LOG2 = 1 << 9,
|
2018-01-16 10:51:45 +08:00
|
|
|
HIST_FIELD_FL_TIMESTAMP = 1 << 10,
|
2018-01-16 10:51:48 +08:00
|
|
|
HIST_FIELD_FL_TIMESTAMP_USECS = 1 << 11,
|
2018-01-16 10:51:49 +08:00
|
|
|
HIST_FIELD_FL_VAR = 1 << 12,
|
2018-01-16 10:51:52 +08:00
|
|
|
HIST_FIELD_FL_EXPR = 1 << 13,
|
2018-01-16 10:51:56 +08:00
|
|
|
HIST_FIELD_FL_VAR_REF = 1 << 14,
|
2018-01-16 10:52:03 +08:00
|
|
|
HIST_FIELD_FL_CPU = 1 << 15,
|
2018-01-16 10:52:04 +08:00
|
|
|
HIST_FIELD_FL_ALIAS = 1 << 16,
|
2018-01-16 10:51:49 +08:00
|
|
|
};
|
|
|
|
|
|
|
|
|
|
struct var_defs {
|
|
|
|
|
unsigned int n_vars;
|
|
|
|
|
char *name[TRACING_MAP_VARS_MAX];
|
|
|
|
|
char *expr[TRACING_MAP_VARS_MAX];
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
};
|
|
|
|
|
|
|
|
|
|
struct hist_trigger_attrs {
|
|
|
|
|
char *keys_str;
|
2016-03-04 02:54:43 +08:00
|
|
|
char *vals_str;
|
2016-03-04 02:54:45 +08:00
|
|
|
char *sort_key_str;
|
2016-03-04 02:54:59 +08:00
|
|
|
char *name;
|
2018-01-16 10:52:08 +08:00
|
|
|
char *clock;
|
2016-03-04 02:54:46 +08:00
|
|
|
bool pause;
|
|
|
|
|
bool cont;
|
2016-03-04 02:54:47 +08:00
|
|
|
bool clear;
|
2018-01-16 10:51:48 +08:00
|
|
|
bool ts_in_usecs;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
unsigned int map_bits;
|
2018-01-16 10:51:49 +08:00
|
|
|
|
|
|
|
|
char *assignment_str[TRACING_MAP_VARS_MAX];
|
|
|
|
|
unsigned int n_assignments;
|
|
|
|
|
|
2018-01-16 10:51:57 +08:00
|
|
|
char *action_str[HIST_ACTIONS_MAX];
|
|
|
|
|
unsigned int n_actions;
|
|
|
|
|
|
2018-01-16 10:51:49 +08:00
|
|
|
struct var_defs var_defs;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
};
|
|
|
|
|
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:51:59 +08:00
|
|
|
struct field_var {
|
|
|
|
|
struct hist_field *var;
|
|
|
|
|
struct hist_field *val;
|
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
struct field_var_hist {
|
|
|
|
|
struct hist_trigger_data *hist_data;
|
|
|
|
|
char *cmd;
|
|
|
|
|
};
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
struct hist_trigger_data {
|
2018-01-16 10:51:49 +08:00
|
|
|
struct hist_field *fields[HIST_FIELDS_MAX];
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
unsigned int n_vals;
|
|
|
|
|
unsigned int n_keys;
|
|
|
|
|
unsigned int n_fields;
|
2018-01-16 10:51:49 +08:00
|
|
|
unsigned int n_vars;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
unsigned int key_size;
|
|
|
|
|
struct tracing_map_sort_key sort_keys[TRACING_MAP_SORT_KEYS_MAX];
|
|
|
|
|
unsigned int n_sort_keys;
|
|
|
|
|
struct trace_event_file *event_file;
|
|
|
|
|
struct hist_trigger_attrs *attrs;
|
|
|
|
|
struct tracing_map *map;
|
2018-01-16 10:51:45 +08:00
|
|
|
bool enable_timestamps;
|
2018-01-16 10:51:49 +08:00
|
|
|
bool remove;
|
2018-01-16 10:51:56 +08:00
|
|
|
struct hist_field *var_refs[TRACING_MAP_VARS_MAX];
|
|
|
|
|
unsigned int n_var_refs;
|
2018-01-16 10:51:57 +08:00
|
|
|
|
|
|
|
|
struct action_data *actions[HIST_ACTIONS_MAX];
|
|
|
|
|
unsigned int n_actions;
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:51:59 +08:00
|
|
|
|
2018-01-16 10:52:00 +08:00
|
|
|
struct hist_field *synth_var_refs[SYNTH_FIELDS_MAX];
|
|
|
|
|
unsigned int n_synth_var_refs;
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:51:59 +08:00
|
|
|
struct field_var *field_vars[SYNTH_FIELDS_MAX];
|
|
|
|
|
unsigned int n_field_vars;
|
|
|
|
|
unsigned int n_field_var_str;
|
|
|
|
|
struct field_var_hist *field_var_hists[SYNTH_FIELDS_MAX];
|
|
|
|
|
unsigned int n_field_var_hists;
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:52:01 +08:00
|
|
|
|
|
|
|
|
struct field_var *max_vars[SYNTH_FIELDS_MAX];
|
|
|
|
|
unsigned int n_max_vars;
|
|
|
|
|
unsigned int n_max_var_str;
|
2018-01-16 10:51:57 +08:00
|
|
|
};
|
|
|
|
|
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:51:58 +08:00
|
|
|
struct synth_field {
|
|
|
|
|
char *type;
|
|
|
|
|
char *name;
|
|
|
|
|
size_t size;
|
|
|
|
|
bool is_signed;
|
|
|
|
|
bool is_string;
|
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
struct synth_event {
|
|
|
|
|
struct list_head list;
|
|
|
|
|
int ref;
|
|
|
|
|
char *name;
|
|
|
|
|
struct synth_field **fields;
|
|
|
|
|
unsigned int n_fields;
|
|
|
|
|
unsigned int n_u64;
|
|
|
|
|
struct trace_event_class class;
|
|
|
|
|
struct trace_event_call call;
|
|
|
|
|
struct tracepoint *tp;
|
|
|
|
|
};
|
|
|
|
|
|
2018-01-16 10:51:57 +08:00
|
|
|
struct action_data;
|
|
|
|
|
|
|
|
|
|
typedef void (*action_fn_t) (struct hist_trigger_data *hist_data,
|
|
|
|
|
struct tracing_map_elt *elt, void *rec,
|
|
|
|
|
struct ring_buffer_event *rbe,
|
|
|
|
|
struct action_data *data, u64 *var_ref_vals);
|
|
|
|
|
|
|
|
|
|
struct action_data {
|
|
|
|
|
action_fn_t fn;
|
2018-01-16 10:52:00 +08:00
|
|
|
unsigned int n_params;
|
|
|
|
|
char *params[SYNTH_FIELDS_MAX];
|
|
|
|
|
|
|
|
|
|
union {
|
|
|
|
|
struct {
|
|
|
|
|
unsigned int var_ref_idx;
|
|
|
|
|
char *match_event;
|
|
|
|
|
char *match_event_system;
|
|
|
|
|
char *synth_event_name;
|
|
|
|
|
struct synth_event *synth_event;
|
|
|
|
|
} onmatch;
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:52:01 +08:00
|
|
|
|
|
|
|
|
struct {
|
|
|
|
|
char *var_str;
|
|
|
|
|
char *fn_name;
|
|
|
|
|
unsigned int max_var_ref_idx;
|
|
|
|
|
struct hist_field *max_var;
|
|
|
|
|
struct hist_field *var;
|
|
|
|
|
} onmax;
|
2018-01-16 10:52:00 +08:00
|
|
|
};
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
};
|
|
|
|
|
|
2018-01-16 10:52:05 +08:00
|
|
|
|
|
|
|
|
static char last_hist_cmd[MAX_FILTER_STR_VAL];
|
|
|
|
|
static char hist_err_str[MAX_FILTER_STR_VAL];
|
|
|
|
|
|
|
|
|
|
static void last_cmd_set(char *str)
|
|
|
|
|
{
|
|
|
|
|
if (!str)
|
|
|
|
|
return;
|
|
|
|
|
|
|
|
|
|
strncpy(last_hist_cmd, str, MAX_FILTER_STR_VAL - 1);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void hist_err(char *str, char *var)
|
|
|
|
|
{
|
|
|
|
|
int maxlen = MAX_FILTER_STR_VAL - 1;
|
|
|
|
|
|
|
|
|
|
if (!str)
|
|
|
|
|
return;
|
|
|
|
|
|
|
|
|
|
if (strlen(hist_err_str))
|
|
|
|
|
return;
|
|
|
|
|
|
|
|
|
|
if (!var)
|
|
|
|
|
var = "";
|
|
|
|
|
|
|
|
|
|
if (strlen(hist_err_str) + strlen(str) + strlen(var) > maxlen)
|
|
|
|
|
return;
|
|
|
|
|
|
|
|
|
|
strcat(hist_err_str, str);
|
|
|
|
|
strcat(hist_err_str, var);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void hist_err_event(char *str, char *system, char *event, char *var)
|
|
|
|
|
{
|
|
|
|
|
char err[MAX_FILTER_STR_VAL];
|
|
|
|
|
|
|
|
|
|
if (system && var)
|
|
|
|
|
snprintf(err, MAX_FILTER_STR_VAL, "%s.%s.%s", system, event, var);
|
|
|
|
|
else if (system)
|
|
|
|
|
snprintf(err, MAX_FILTER_STR_VAL, "%s.%s", system, event);
|
|
|
|
|
else
|
|
|
|
|
strncpy(err, var, MAX_FILTER_STR_VAL);
|
|
|
|
|
|
|
|
|
|
hist_err(str, err);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void hist_err_clear(void)
|
|
|
|
|
{
|
|
|
|
|
hist_err_str[0] = '\0';
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static bool have_hist_err(void)
|
|
|
|
|
{
|
|
|
|
|
if (strlen(hist_err_str))
|
|
|
|
|
return true;
|
|
|
|
|
|
|
|
|
|
return false;
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:51:58 +08:00
|
|
|
static LIST_HEAD(synth_event_list);
|
|
|
|
|
static DEFINE_MUTEX(synth_event_mutex);
|
|
|
|
|
|
|
|
|
|
struct synth_trace_event {
|
|
|
|
|
struct trace_entry ent;
|
|
|
|
|
u64 fields[];
|
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
static int synth_event_define_fields(struct trace_event_call *call)
|
|
|
|
|
{
|
|
|
|
|
struct synth_trace_event trace;
|
|
|
|
|
int offset = offsetof(typeof(trace), fields);
|
|
|
|
|
struct synth_event *event = call->data;
|
|
|
|
|
unsigned int i, size, n_u64;
|
|
|
|
|
char *name, *type;
|
|
|
|
|
bool is_signed;
|
|
|
|
|
int ret = 0;
|
|
|
|
|
|
|
|
|
|
for (i = 0, n_u64 = 0; i < event->n_fields; i++) {
|
|
|
|
|
size = event->fields[i]->size;
|
|
|
|
|
is_signed = event->fields[i]->is_signed;
|
|
|
|
|
type = event->fields[i]->type;
|
|
|
|
|
name = event->fields[i]->name;
|
|
|
|
|
ret = trace_define_field(call, type, name, offset, size,
|
|
|
|
|
is_signed, FILTER_OTHER);
|
|
|
|
|
if (ret)
|
|
|
|
|
break;
|
|
|
|
|
|
|
|
|
|
if (event->fields[i]->is_string) {
|
|
|
|
|
offset += STR_VAR_LEN_MAX;
|
|
|
|
|
n_u64 += STR_VAR_LEN_MAX / sizeof(u64);
|
|
|
|
|
} else {
|
|
|
|
|
offset += sizeof(u64);
|
|
|
|
|
n_u64++;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
event->n_u64 = n_u64;
|
|
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static bool synth_field_signed(char *type)
|
|
|
|
|
{
|
|
|
|
|
if (strncmp(type, "u", 1) == 0)
|
|
|
|
|
return false;
|
|
|
|
|
|
|
|
|
|
return true;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int synth_field_is_string(char *type)
|
|
|
|
|
{
|
|
|
|
|
if (strstr(type, "char[") != NULL)
|
|
|
|
|
return true;
|
|
|
|
|
|
|
|
|
|
return false;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int synth_field_string_size(char *type)
|
|
|
|
|
{
|
|
|
|
|
char buf[4], *end, *start;
|
|
|
|
|
unsigned int len;
|
|
|
|
|
int size, err;
|
|
|
|
|
|
|
|
|
|
start = strstr(type, "char[");
|
|
|
|
|
if (start == NULL)
|
|
|
|
|
return -EINVAL;
|
|
|
|
|
start += strlen("char[");
|
|
|
|
|
|
|
|
|
|
end = strchr(type, ']');
|
|
|
|
|
if (!end || end < start)
|
|
|
|
|
return -EINVAL;
|
|
|
|
|
|
|
|
|
|
len = end - start;
|
|
|
|
|
if (len > 3)
|
|
|
|
|
return -EINVAL;
|
|
|
|
|
|
|
|
|
|
strncpy(buf, start, len);
|
|
|
|
|
buf[len] = '\0';
|
|
|
|
|
|
|
|
|
|
err = kstrtouint(buf, 0, &size);
|
|
|
|
|
if (err)
|
|
|
|
|
return err;
|
|
|
|
|
|
|
|
|
|
if (size > STR_VAR_LEN_MAX)
|
|
|
|
|
return -EINVAL;
|
|
|
|
|
|
|
|
|
|
return size;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int synth_field_size(char *type)
|
|
|
|
|
{
|
|
|
|
|
int size = 0;
|
|
|
|
|
|
|
|
|
|
if (strcmp(type, "s64") == 0)
|
|
|
|
|
size = sizeof(s64);
|
|
|
|
|
else if (strcmp(type, "u64") == 0)
|
|
|
|
|
size = sizeof(u64);
|
|
|
|
|
else if (strcmp(type, "s32") == 0)
|
|
|
|
|
size = sizeof(s32);
|
|
|
|
|
else if (strcmp(type, "u32") == 0)
|
|
|
|
|
size = sizeof(u32);
|
|
|
|
|
else if (strcmp(type, "s16") == 0)
|
|
|
|
|
size = sizeof(s16);
|
|
|
|
|
else if (strcmp(type, "u16") == 0)
|
|
|
|
|
size = sizeof(u16);
|
|
|
|
|
else if (strcmp(type, "s8") == 0)
|
|
|
|
|
size = sizeof(s8);
|
|
|
|
|
else if (strcmp(type, "u8") == 0)
|
|
|
|
|
size = sizeof(u8);
|
|
|
|
|
else if (strcmp(type, "char") == 0)
|
|
|
|
|
size = sizeof(char);
|
|
|
|
|
else if (strcmp(type, "unsigned char") == 0)
|
|
|
|
|
size = sizeof(unsigned char);
|
|
|
|
|
else if (strcmp(type, "int") == 0)
|
|
|
|
|
size = sizeof(int);
|
|
|
|
|
else if (strcmp(type, "unsigned int") == 0)
|
|
|
|
|
size = sizeof(unsigned int);
|
|
|
|
|
else if (strcmp(type, "long") == 0)
|
|
|
|
|
size = sizeof(long);
|
|
|
|
|
else if (strcmp(type, "unsigned long") == 0)
|
|
|
|
|
size = sizeof(unsigned long);
|
|
|
|
|
else if (strcmp(type, "pid_t") == 0)
|
|
|
|
|
size = sizeof(pid_t);
|
|
|
|
|
else if (synth_field_is_string(type))
|
|
|
|
|
size = synth_field_string_size(type);
|
|
|
|
|
|
|
|
|
|
return size;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static const char *synth_field_fmt(char *type)
|
|
|
|
|
{
|
|
|
|
|
const char *fmt = "%llu";
|
|
|
|
|
|
|
|
|
|
if (strcmp(type, "s64") == 0)
|
|
|
|
|
fmt = "%lld";
|
|
|
|
|
else if (strcmp(type, "u64") == 0)
|
|
|
|
|
fmt = "%llu";
|
|
|
|
|
else if (strcmp(type, "s32") == 0)
|
|
|
|
|
fmt = "%d";
|
|
|
|
|
else if (strcmp(type, "u32") == 0)
|
|
|
|
|
fmt = "%u";
|
|
|
|
|
else if (strcmp(type, "s16") == 0)
|
|
|
|
|
fmt = "%d";
|
|
|
|
|
else if (strcmp(type, "u16") == 0)
|
|
|
|
|
fmt = "%u";
|
|
|
|
|
else if (strcmp(type, "s8") == 0)
|
|
|
|
|
fmt = "%d";
|
|
|
|
|
else if (strcmp(type, "u8") == 0)
|
|
|
|
|
fmt = "%u";
|
|
|
|
|
else if (strcmp(type, "char") == 0)
|
|
|
|
|
fmt = "%d";
|
|
|
|
|
else if (strcmp(type, "unsigned char") == 0)
|
|
|
|
|
fmt = "%u";
|
|
|
|
|
else if (strcmp(type, "int") == 0)
|
|
|
|
|
fmt = "%d";
|
|
|
|
|
else if (strcmp(type, "unsigned int") == 0)
|
|
|
|
|
fmt = "%u";
|
|
|
|
|
else if (strcmp(type, "long") == 0)
|
|
|
|
|
fmt = "%ld";
|
|
|
|
|
else if (strcmp(type, "unsigned long") == 0)
|
|
|
|
|
fmt = "%lu";
|
|
|
|
|
else if (strcmp(type, "pid_t") == 0)
|
|
|
|
|
fmt = "%d";
|
|
|
|
|
else if (synth_field_is_string(type))
|
|
|
|
|
fmt = "%s";
|
|
|
|
|
|
|
|
|
|
return fmt;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static enum print_line_t print_synth_event(struct trace_iterator *iter,
|
|
|
|
|
int flags,
|
|
|
|
|
struct trace_event *event)
|
|
|
|
|
{
|
|
|
|
|
struct trace_array *tr = iter->tr;
|
|
|
|
|
struct trace_seq *s = &iter->seq;
|
|
|
|
|
struct synth_trace_event *entry;
|
|
|
|
|
struct synth_event *se;
|
|
|
|
|
unsigned int i, n_u64;
|
|
|
|
|
char print_fmt[32];
|
|
|
|
|
const char *fmt;
|
|
|
|
|
|
|
|
|
|
entry = (struct synth_trace_event *)iter->ent;
|
|
|
|
|
se = container_of(event, struct synth_event, call.event);
|
|
|
|
|
|
|
|
|
|
trace_seq_printf(s, "%s: ", se->name);
|
|
|
|
|
|
|
|
|
|
for (i = 0, n_u64 = 0; i < se->n_fields; i++) {
|
|
|
|
|
if (trace_seq_has_overflowed(s))
|
|
|
|
|
goto end;
|
|
|
|
|
|
|
|
|
|
fmt = synth_field_fmt(se->fields[i]->type);
|
|
|
|
|
|
|
|
|
|
/* parameter types */
|
|
|
|
|
if (tr->trace_flags & TRACE_ITER_VERBOSE)
|
|
|
|
|
trace_seq_printf(s, "%s ", fmt);
|
|
|
|
|
|
|
|
|
|
snprintf(print_fmt, sizeof(print_fmt), "%%s=%s%%s", fmt);
|
|
|
|
|
|
|
|
|
|
/* parameter values */
|
|
|
|
|
if (se->fields[i]->is_string) {
|
|
|
|
|
trace_seq_printf(s, print_fmt, se->fields[i]->name,
|
|
|
|
|
(char *)&entry->fields[n_u64],
|
|
|
|
|
i == se->n_fields - 1 ? "" : " ");
|
|
|
|
|
n_u64 += STR_VAR_LEN_MAX / sizeof(u64);
|
|
|
|
|
} else {
|
|
|
|
|
trace_seq_printf(s, print_fmt, se->fields[i]->name,
|
|
|
|
|
entry->fields[n_u64],
|
|
|
|
|
i == se->n_fields - 1 ? "" : " ");
|
|
|
|
|
n_u64++;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
end:
|
|
|
|
|
trace_seq_putc(s, '\n');
|
|
|
|
|
|
|
|
|
|
return trace_handle_return(s);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static struct trace_event_functions synth_event_funcs = {
|
|
|
|
|
.trace = print_synth_event
|
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
static notrace void trace_event_raw_event_synth(void *__data,
|
|
|
|
|
u64 *var_ref_vals,
|
|
|
|
|
unsigned int var_ref_idx)
|
|
|
|
|
{
|
|
|
|
|
struct trace_event_file *trace_file = __data;
|
|
|
|
|
struct synth_trace_event *entry;
|
|
|
|
|
struct trace_event_buffer fbuffer;
|
2018-02-08 06:29:46 +08:00
|
|
|
struct ring_buffer *buffer;
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:51:58 +08:00
|
|
|
struct synth_event *event;
|
|
|
|
|
unsigned int i, n_u64;
|
|
|
|
|
int fields_size = 0;
|
|
|
|
|
|
|
|
|
|
event = trace_file->event_call->data;
|
|
|
|
|
|
|
|
|
|
if (trace_trigger_soft_disabled(trace_file))
|
|
|
|
|
return;
|
|
|
|
|
|
|
|
|
|
fields_size = event->n_u64 * sizeof(u64);
|
|
|
|
|
|
2018-02-08 06:29:46 +08:00
|
|
|
/*
|
|
|
|
|
* Avoid ring buffer recursion detection, as this event
|
|
|
|
|
* is being performed within another event.
|
|
|
|
|
*/
|
|
|
|
|
buffer = trace_file->tr->trace_buffer.buffer;
|
|
|
|
|
ring_buffer_nest_start(buffer);
|
|
|
|
|
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:51:58 +08:00
|
|
|
entry = trace_event_buffer_reserve(&fbuffer, trace_file,
|
|
|
|
|
sizeof(*entry) + fields_size);
|
|
|
|
|
if (!entry)
|
2018-02-08 06:29:46 +08:00
|
|
|
goto out;
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:51:58 +08:00
|
|
|
|
|
|
|
|
for (i = 0, n_u64 = 0; i < event->n_fields; i++) {
|
|
|
|
|
if (event->fields[i]->is_string) {
|
|
|
|
|
char *str_val = (char *)(long)var_ref_vals[var_ref_idx + i];
|
|
|
|
|
char *str_field = (char *)&entry->fields[n_u64];
|
|
|
|
|
|
|
|
|
|
strncpy(str_field, str_val, STR_VAR_LEN_MAX);
|
|
|
|
|
n_u64 += STR_VAR_LEN_MAX / sizeof(u64);
|
|
|
|
|
} else {
|
|
|
|
|
entry->fields[n_u64] = var_ref_vals[var_ref_idx + i];
|
|
|
|
|
n_u64++;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
trace_event_buffer_commit(&fbuffer);
|
2018-02-08 06:29:46 +08:00
|
|
|
out:
|
|
|
|
|
ring_buffer_nest_end(buffer);
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:51:58 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void free_synth_event_print_fmt(struct trace_event_call *call)
|
|
|
|
|
{
|
|
|
|
|
if (call) {
|
|
|
|
|
kfree(call->print_fmt);
|
|
|
|
|
call->print_fmt = NULL;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int __set_synth_event_print_fmt(struct synth_event *event,
|
|
|
|
|
char *buf, int len)
|
|
|
|
|
{
|
|
|
|
|
const char *fmt;
|
|
|
|
|
int pos = 0;
|
|
|
|
|
int i;
|
|
|
|
|
|
|
|
|
|
/* When len=0, we just calculate the needed length */
|
|
|
|
|
#define LEN_OR_ZERO (len ? len - pos : 0)
|
|
|
|
|
|
|
|
|
|
pos += snprintf(buf + pos, LEN_OR_ZERO, "\"");
|
|
|
|
|
for (i = 0; i < event->n_fields; i++) {
|
|
|
|
|
fmt = synth_field_fmt(event->fields[i]->type);
|
|
|
|
|
pos += snprintf(buf + pos, LEN_OR_ZERO, "%s=%s%s",
|
|
|
|
|
event->fields[i]->name, fmt,
|
|
|
|
|
i == event->n_fields - 1 ? "" : ", ");
|
|
|
|
|
}
|
|
|
|
|
pos += snprintf(buf + pos, LEN_OR_ZERO, "\"");
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < event->n_fields; i++) {
|
|
|
|
|
pos += snprintf(buf + pos, LEN_OR_ZERO,
|
|
|
|
|
", REC->%s", event->fields[i]->name);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
#undef LEN_OR_ZERO
|
|
|
|
|
|
|
|
|
|
/* return the length of print_fmt */
|
|
|
|
|
return pos;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int set_synth_event_print_fmt(struct trace_event_call *call)
|
|
|
|
|
{
|
|
|
|
|
struct synth_event *event = call->data;
|
|
|
|
|
char *print_fmt;
|
|
|
|
|
int len;
|
|
|
|
|
|
|
|
|
|
/* First: called with 0 length to calculate the needed length */
|
|
|
|
|
len = __set_synth_event_print_fmt(event, NULL, 0);
|
|
|
|
|
|
|
|
|
|
print_fmt = kmalloc(len + 1, GFP_KERNEL);
|
|
|
|
|
if (!print_fmt)
|
|
|
|
|
return -ENOMEM;
|
|
|
|
|
|
|
|
|
|
/* Second: actually write the @print_fmt */
|
|
|
|
|
__set_synth_event_print_fmt(event, print_fmt, len + 1);
|
|
|
|
|
call->print_fmt = print_fmt;
|
|
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void free_synth_field(struct synth_field *field)
|
|
|
|
|
{
|
|
|
|
|
kfree(field->type);
|
|
|
|
|
kfree(field->name);
|
|
|
|
|
kfree(field);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static struct synth_field *parse_synth_field(char *field_type,
|
|
|
|
|
char *field_name)
|
|
|
|
|
{
|
|
|
|
|
struct synth_field *field;
|
|
|
|
|
int len, ret = 0;
|
|
|
|
|
char *array;
|
|
|
|
|
|
|
|
|
|
if (field_type[0] == ';')
|
|
|
|
|
field_type++;
|
|
|
|
|
|
|
|
|
|
len = strlen(field_name);
|
|
|
|
|
if (field_name[len - 1] == ';')
|
|
|
|
|
field_name[len - 1] = '\0';
|
|
|
|
|
|
|
|
|
|
field = kzalloc(sizeof(*field), GFP_KERNEL);
|
|
|
|
|
if (!field)
|
|
|
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
|
|
|
|
|
|
len = strlen(field_type) + 1;
|
|
|
|
|
array = strchr(field_name, '[');
|
|
|
|
|
if (array)
|
|
|
|
|
len += strlen(array);
|
|
|
|
|
field->type = kzalloc(len, GFP_KERNEL);
|
|
|
|
|
if (!field->type) {
|
|
|
|
|
ret = -ENOMEM;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
|
|
|
|
strcat(field->type, field_type);
|
|
|
|
|
if (array) {
|
|
|
|
|
strcat(field->type, array);
|
|
|
|
|
*array = '\0';
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
field->size = synth_field_size(field->type);
|
|
|
|
|
if (!field->size) {
|
|
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if (synth_field_is_string(field->type))
|
|
|
|
|
field->is_string = true;
|
|
|
|
|
|
|
|
|
|
field->is_signed = synth_field_signed(field->type);
|
|
|
|
|
|
|
|
|
|
field->name = kstrdup(field_name, GFP_KERNEL);
|
|
|
|
|
if (!field->name) {
|
|
|
|
|
ret = -ENOMEM;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
|
|
|
|
out:
|
|
|
|
|
return field;
|
|
|
|
|
free:
|
|
|
|
|
free_synth_field(field);
|
|
|
|
|
field = ERR_PTR(ret);
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void free_synth_tracepoint(struct tracepoint *tp)
|
|
|
|
|
{
|
|
|
|
|
if (!tp)
|
|
|
|
|
return;
|
|
|
|
|
|
|
|
|
|
kfree(tp->name);
|
|
|
|
|
kfree(tp);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static struct tracepoint *alloc_synth_tracepoint(char *name)
|
|
|
|
|
{
|
|
|
|
|
struct tracepoint *tp;
|
|
|
|
|
|
|
|
|
|
tp = kzalloc(sizeof(*tp), GFP_KERNEL);
|
|
|
|
|
if (!tp)
|
|
|
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
|
|
|
|
|
|
tp->name = kstrdup(name, GFP_KERNEL);
|
|
|
|
|
if (!tp->name) {
|
|
|
|
|
kfree(tp);
|
|
|
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return tp;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
typedef void (*synth_probe_func_t) (void *__data, u64 *var_ref_vals,
|
|
|
|
|
unsigned int var_ref_idx);
|
|
|
|
|
|
|
|
|
|
static inline void trace_synth(struct synth_event *event, u64 *var_ref_vals,
|
|
|
|
|
unsigned int var_ref_idx)
|
|
|
|
|
{
|
|
|
|
|
struct tracepoint *tp = event->tp;
|
|
|
|
|
|
|
|
|
|
if (unlikely(atomic_read(&tp->key.enabled) > 0)) {
|
|
|
|
|
struct tracepoint_func *probe_func_ptr;
|
|
|
|
|
synth_probe_func_t probe_func;
|
|
|
|
|
void *__data;
|
|
|
|
|
|
|
|
|
|
if (!(cpu_online(raw_smp_processor_id())))
|
|
|
|
|
return;
|
|
|
|
|
|
|
|
|
|
probe_func_ptr = rcu_dereference_sched((tp)->funcs);
|
|
|
|
|
if (probe_func_ptr) {
|
|
|
|
|
do {
|
|
|
|
|
probe_func = probe_func_ptr->func;
|
|
|
|
|
__data = probe_func_ptr->data;
|
|
|
|
|
probe_func(__data, var_ref_vals, var_ref_idx);
|
|
|
|
|
} while ((++probe_func_ptr)->func);
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static struct synth_event *find_synth_event(const char *name)
|
|
|
|
|
{
|
|
|
|
|
struct synth_event *event;
|
|
|
|
|
|
|
|
|
|
list_for_each_entry(event, &synth_event_list, list) {
|
|
|
|
|
if (strcmp(event->name, name) == 0)
|
|
|
|
|
return event;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return NULL;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int register_synth_event(struct synth_event *event)
|
|
|
|
|
{
|
|
|
|
|
struct trace_event_call *call = &event->call;
|
|
|
|
|
int ret = 0;
|
|
|
|
|
|
|
|
|
|
event->call.class = &event->class;
|
|
|
|
|
event->class.system = kstrdup(SYNTH_SYSTEM, GFP_KERNEL);
|
|
|
|
|
if (!event->class.system) {
|
|
|
|
|
ret = -ENOMEM;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
event->tp = alloc_synth_tracepoint(event->name);
|
|
|
|
|
if (IS_ERR(event->tp)) {
|
|
|
|
|
ret = PTR_ERR(event->tp);
|
|
|
|
|
event->tp = NULL;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
INIT_LIST_HEAD(&call->class->fields);
|
|
|
|
|
call->event.funcs = &synth_event_funcs;
|
|
|
|
|
call->class->define_fields = synth_event_define_fields;
|
|
|
|
|
|
|
|
|
|
ret = register_trace_event(&call->event);
|
|
|
|
|
if (!ret) {
|
|
|
|
|
ret = -ENODEV;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
call->flags = TRACE_EVENT_FL_TRACEPOINT;
|
|
|
|
|
call->class->reg = trace_event_reg;
|
|
|
|
|
call->class->probe = trace_event_raw_event_synth;
|
|
|
|
|
call->data = event;
|
|
|
|
|
call->tp = event->tp;
|
|
|
|
|
|
|
|
|
|
ret = trace_add_event_call(call);
|
|
|
|
|
if (ret) {
|
|
|
|
|
pr_warn("Failed to register synthetic event: %s\n",
|
|
|
|
|
trace_event_name(call));
|
|
|
|
|
goto err;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
ret = set_synth_event_print_fmt(call);
|
|
|
|
|
if (ret < 0) {
|
|
|
|
|
trace_remove_event_call(call);
|
|
|
|
|
goto err;
|
|
|
|
|
}
|
|
|
|
|
out:
|
|
|
|
|
return ret;
|
|
|
|
|
err:
|
|
|
|
|
unregister_trace_event(&call->event);
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int unregister_synth_event(struct synth_event *event)
|
|
|
|
|
{
|
|
|
|
|
struct trace_event_call *call = &event->call;
|
|
|
|
|
int ret;
|
|
|
|
|
|
|
|
|
|
ret = trace_remove_event_call(call);
|
|
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void free_synth_event(struct synth_event *event)
|
|
|
|
|
{
|
|
|
|
|
unsigned int i;
|
|
|
|
|
|
|
|
|
|
if (!event)
|
|
|
|
|
return;
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < event->n_fields; i++)
|
|
|
|
|
free_synth_field(event->fields[i]);
|
|
|
|
|
|
|
|
|
|
kfree(event->fields);
|
|
|
|
|
kfree(event->name);
|
|
|
|
|
kfree(event->class.system);
|
|
|
|
|
free_synth_tracepoint(event->tp);
|
|
|
|
|
free_synth_event_print_fmt(&event->call);
|
|
|
|
|
kfree(event);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static struct synth_event *alloc_synth_event(char *event_name, int n_fields,
|
|
|
|
|
struct synth_field **fields)
|
|
|
|
|
{
|
|
|
|
|
struct synth_event *event;
|
|
|
|
|
unsigned int i;
|
|
|
|
|
|
|
|
|
|
event = kzalloc(sizeof(*event), GFP_KERNEL);
|
|
|
|
|
if (!event) {
|
|
|
|
|
event = ERR_PTR(-ENOMEM);
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
event->name = kstrdup(event_name, GFP_KERNEL);
|
|
|
|
|
if (!event->name) {
|
|
|
|
|
kfree(event);
|
|
|
|
|
event = ERR_PTR(-ENOMEM);
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
event->fields = kcalloc(n_fields, sizeof(*event->fields), GFP_KERNEL);
|
|
|
|
|
if (!event->fields) {
|
|
|
|
|
free_synth_event(event);
|
|
|
|
|
event = ERR_PTR(-ENOMEM);
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < n_fields; i++)
|
|
|
|
|
event->fields[i] = fields[i];
|
|
|
|
|
|
|
|
|
|
event->n_fields = n_fields;
|
|
|
|
|
out:
|
|
|
|
|
return event;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:52:00 +08:00
|
|
|
static void action_trace(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct tracing_map_elt *elt, void *rec,
|
|
|
|
|
struct ring_buffer_event *rbe,
|
|
|
|
|
struct action_data *data, u64 *var_ref_vals)
|
|
|
|
|
{
|
|
|
|
|
struct synth_event *event = data->onmatch.synth_event;
|
|
|
|
|
|
|
|
|
|
trace_synth(event, var_ref_vals, data->onmatch.var_ref_idx);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
struct hist_var_data {
|
|
|
|
|
struct list_head list;
|
|
|
|
|
struct hist_trigger_data *hist_data;
|
|
|
|
|
};
|
|
|
|
|
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:51:58 +08:00
|
|
|
static void add_or_delete_synth_event(struct synth_event *event, int delete)
|
|
|
|
|
{
|
|
|
|
|
if (delete)
|
|
|
|
|
free_synth_event(event);
|
|
|
|
|
else {
|
|
|
|
|
mutex_lock(&synth_event_mutex);
|
|
|
|
|
if (!find_synth_event(event->name))
|
|
|
|
|
list_add(&event->list, &synth_event_list);
|
|
|
|
|
else
|
|
|
|
|
free_synth_event(event);
|
|
|
|
|
mutex_unlock(&synth_event_mutex);
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int create_synth_event(int argc, char **argv)
|
|
|
|
|
{
|
|
|
|
|
struct synth_field *field, *fields[SYNTH_FIELDS_MAX];
|
|
|
|
|
struct synth_event *event = NULL;
|
|
|
|
|
bool delete_event = false;
|
|
|
|
|
int i, n_fields = 0, ret = 0;
|
|
|
|
|
char *name;
|
|
|
|
|
|
|
|
|
|
mutex_lock(&synth_event_mutex);
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Argument syntax:
|
|
|
|
|
* - Add synthetic event: <event_name> field[;field] ...
|
|
|
|
|
* - Remove synthetic event: !<event_name> field[;field] ...
|
|
|
|
|
* where 'field' = type field_name
|
|
|
|
|
*/
|
|
|
|
|
if (argc < 1) {
|
|
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
name = argv[0];
|
|
|
|
|
if (name[0] == '!') {
|
|
|
|
|
delete_event = true;
|
|
|
|
|
name++;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
event = find_synth_event(name);
|
|
|
|
|
if (event) {
|
|
|
|
|
if (delete_event) {
|
|
|
|
|
if (event->ref) {
|
|
|
|
|
event = NULL;
|
|
|
|
|
ret = -EBUSY;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
list_del(&event->list);
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
event = NULL;
|
|
|
|
|
ret = -EEXIST;
|
|
|
|
|
goto out;
|
|
|
|
|
} else if (delete_event)
|
|
|
|
|
goto out;
|
|
|
|
|
|
|
|
|
|
if (argc < 2) {
|
|
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
for (i = 1; i < argc - 1; i++) {
|
|
|
|
|
if (strcmp(argv[i], ";") == 0)
|
|
|
|
|
continue;
|
|
|
|
|
if (n_fields == SYNTH_FIELDS_MAX) {
|
|
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto err;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
field = parse_synth_field(argv[i], argv[i + 1]);
|
|
|
|
|
if (IS_ERR(field)) {
|
|
|
|
|
ret = PTR_ERR(field);
|
|
|
|
|
goto err;
|
|
|
|
|
}
|
|
|
|
|
fields[n_fields] = field;
|
|
|
|
|
i++; n_fields++;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if (i < argc) {
|
|
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto err;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
event = alloc_synth_event(name, n_fields, fields);
|
|
|
|
|
if (IS_ERR(event)) {
|
|
|
|
|
ret = PTR_ERR(event);
|
|
|
|
|
event = NULL;
|
|
|
|
|
goto err;
|
|
|
|
|
}
|
|
|
|
|
out:
|
|
|
|
|
mutex_unlock(&synth_event_mutex);
|
|
|
|
|
|
|
|
|
|
if (event) {
|
|
|
|
|
if (delete_event) {
|
|
|
|
|
ret = unregister_synth_event(event);
|
|
|
|
|
add_or_delete_synth_event(event, !ret);
|
|
|
|
|
} else {
|
|
|
|
|
ret = register_synth_event(event);
|
|
|
|
|
add_or_delete_synth_event(event, ret);
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
|
err:
|
|
|
|
|
mutex_unlock(&synth_event_mutex);
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < n_fields; i++)
|
|
|
|
|
free_synth_field(fields[i]);
|
|
|
|
|
free_synth_event(event);
|
|
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int release_all_synth_events(void)
|
|
|
|
|
{
|
|
|
|
|
struct list_head release_events;
|
|
|
|
|
struct synth_event *event, *e;
|
|
|
|
|
int ret = 0;
|
|
|
|
|
|
|
|
|
|
INIT_LIST_HEAD(&release_events);
|
|
|
|
|
|
|
|
|
|
mutex_lock(&synth_event_mutex);
|
|
|
|
|
|
|
|
|
|
list_for_each_entry(event, &synth_event_list, list) {
|
|
|
|
|
if (event->ref) {
|
|
|
|
|
mutex_unlock(&synth_event_mutex);
|
|
|
|
|
return -EBUSY;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
list_splice_init(&event->list, &release_events);
|
|
|
|
|
|
|
|
|
|
mutex_unlock(&synth_event_mutex);
|
|
|
|
|
|
|
|
|
|
list_for_each_entry_safe(event, e, &release_events, list) {
|
|
|
|
|
list_del(&event->list);
|
|
|
|
|
|
|
|
|
|
ret = unregister_synth_event(event);
|
|
|
|
|
add_or_delete_synth_event(event, !ret);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
static void *synth_events_seq_start(struct seq_file *m, loff_t *pos)
|
|
|
|
|
{
|
|
|
|
|
mutex_lock(&synth_event_mutex);
|
|
|
|
|
|
|
|
|
|
return seq_list_start(&synth_event_list, *pos);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void *synth_events_seq_next(struct seq_file *m, void *v, loff_t *pos)
|
|
|
|
|
{
|
|
|
|
|
return seq_list_next(v, &synth_event_list, pos);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void synth_events_seq_stop(struct seq_file *m, void *v)
|
|
|
|
|
{
|
|
|
|
|
mutex_unlock(&synth_event_mutex);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int synth_events_seq_show(struct seq_file *m, void *v)
|
|
|
|
|
{
|
|
|
|
|
struct synth_field *field;
|
|
|
|
|
struct synth_event *event = v;
|
|
|
|
|
unsigned int i;
|
|
|
|
|
|
|
|
|
|
seq_printf(m, "%s\t", event->name);
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < event->n_fields; i++) {
|
|
|
|
|
field = event->fields[i];
|
|
|
|
|
|
|
|
|
|
/* parameter values */
|
|
|
|
|
seq_printf(m, "%s %s%s", field->type, field->name,
|
|
|
|
|
i == event->n_fields - 1 ? "" : "; ");
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
seq_putc(m, '\n');
|
|
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static const struct seq_operations synth_events_seq_op = {
|
|
|
|
|
.start = synth_events_seq_start,
|
|
|
|
|
.next = synth_events_seq_next,
|
|
|
|
|
.stop = synth_events_seq_stop,
|
|
|
|
|
.show = synth_events_seq_show
|
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
static int synth_events_open(struct inode *inode, struct file *file)
|
|
|
|
|
{
|
|
|
|
|
int ret;
|
|
|
|
|
|
|
|
|
|
if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
|
|
|
|
|
ret = release_all_synth_events();
|
|
|
|
|
if (ret < 0)
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return seq_open(file, &synth_events_seq_op);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static ssize_t synth_events_write(struct file *file,
|
|
|
|
|
const char __user *buffer,
|
|
|
|
|
size_t count, loff_t *ppos)
|
|
|
|
|
{
|
|
|
|
|
return trace_parse_run_command(file, buffer, count, ppos,
|
|
|
|
|
create_synth_event);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static const struct file_operations synth_events_fops = {
|
|
|
|
|
.open = synth_events_open,
|
|
|
|
|
.write = synth_events_write,
|
|
|
|
|
.read = seq_read,
|
|
|
|
|
.llseek = seq_lseek,
|
|
|
|
|
.release = seq_release,
|
|
|
|
|
};
|
|
|
|
|
|
2018-01-16 10:51:54 +08:00
|
|
|
static u64 hist_field_timestamp(struct hist_field *hist_field,
|
|
|
|
|
struct tracing_map_elt *elt,
|
|
|
|
|
struct ring_buffer_event *rbe,
|
|
|
|
|
void *event)
|
2018-01-16 10:51:48 +08:00
|
|
|
{
|
|
|
|
|
struct hist_trigger_data *hist_data = hist_field->hist_data;
|
|
|
|
|
struct trace_array *tr = hist_data->event_file->tr;
|
|
|
|
|
|
|
|
|
|
u64 ts = ring_buffer_event_time_stamp(rbe);
|
|
|
|
|
|
|
|
|
|
if (hist_data->attrs->ts_in_usecs && trace_clock_in_ns(tr))
|
|
|
|
|
ts = ns2usecs(ts);
|
|
|
|
|
|
|
|
|
|
return ts;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:52:03 +08:00
|
|
|
static u64 hist_field_cpu(struct hist_field *hist_field,
|
|
|
|
|
struct tracing_map_elt *elt,
|
|
|
|
|
struct ring_buffer_event *rbe,
|
|
|
|
|
void *event)
|
|
|
|
|
{
|
|
|
|
|
int cpu = smp_processor_id();
|
|
|
|
|
|
|
|
|
|
return cpu;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:51:56 +08:00
|
|
|
static struct hist_field *
|
|
|
|
|
check_field_for_var_ref(struct hist_field *hist_field,
|
|
|
|
|
struct hist_trigger_data *var_data,
|
|
|
|
|
unsigned int var_idx)
|
|
|
|
|
{
|
|
|
|
|
struct hist_field *found = NULL;
|
|
|
|
|
|
|
|
|
|
if (hist_field && hist_field->flags & HIST_FIELD_FL_VAR_REF) {
|
|
|
|
|
if (hist_field->var.idx == var_idx &&
|
|
|
|
|
hist_field->var.hist_data == var_data) {
|
|
|
|
|
found = hist_field;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return found;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static struct hist_field *
|
|
|
|
|
check_field_for_var_refs(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct hist_field *hist_field,
|
|
|
|
|
struct hist_trigger_data *var_data,
|
|
|
|
|
unsigned int var_idx,
|
|
|
|
|
unsigned int level)
|
|
|
|
|
{
|
|
|
|
|
struct hist_field *found = NULL;
|
|
|
|
|
unsigned int i;
|
|
|
|
|
|
|
|
|
|
if (level > 3)
|
|
|
|
|
return found;
|
|
|
|
|
|
|
|
|
|
if (!hist_field)
|
|
|
|
|
return found;
|
|
|
|
|
|
|
|
|
|
found = check_field_for_var_ref(hist_field, var_data, var_idx);
|
|
|
|
|
if (found)
|
|
|
|
|
return found;
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < HIST_FIELD_OPERANDS_MAX; i++) {
|
|
|
|
|
struct hist_field *operand;
|
|
|
|
|
|
|
|
|
|
operand = hist_field->operands[i];
|
|
|
|
|
found = check_field_for_var_refs(hist_data, operand, var_data,
|
|
|
|
|
var_idx, level + 1);
|
|
|
|
|
if (found)
|
|
|
|
|
return found;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return found;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static struct hist_field *find_var_ref(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct hist_trigger_data *var_data,
|
|
|
|
|
unsigned int var_idx)
|
|
|
|
|
{
|
|
|
|
|
struct hist_field *hist_field, *found = NULL;
|
|
|
|
|
unsigned int i;
|
|
|
|
|
|
|
|
|
|
for_each_hist_field(i, hist_data) {
|
|
|
|
|
hist_field = hist_data->fields[i];
|
|
|
|
|
found = check_field_for_var_refs(hist_data, hist_field,
|
|
|
|
|
var_data, var_idx, 0);
|
|
|
|
|
if (found)
|
|
|
|
|
return found;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:52:00 +08:00
|
|
|
for (i = 0; i < hist_data->n_synth_var_refs; i++) {
|
|
|
|
|
hist_field = hist_data->synth_var_refs[i];
|
|
|
|
|
found = check_field_for_var_refs(hist_data, hist_field,
|
|
|
|
|
var_data, var_idx, 0);
|
|
|
|
|
if (found)
|
|
|
|
|
return found;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:51:56 +08:00
|
|
|
return found;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static struct hist_field *find_any_var_ref(struct hist_trigger_data *hist_data,
|
|
|
|
|
unsigned int var_idx)
|
|
|
|
|
{
|
|
|
|
|
struct trace_array *tr = hist_data->event_file->tr;
|
|
|
|
|
struct hist_field *found = NULL;
|
|
|
|
|
struct hist_var_data *var_data;
|
|
|
|
|
|
|
|
|
|
list_for_each_entry(var_data, &tr->hist_vars, list) {
|
|
|
|
|
if (var_data->hist_data == hist_data)
|
|
|
|
|
continue;
|
|
|
|
|
found = find_var_ref(var_data->hist_data, hist_data, var_idx);
|
|
|
|
|
if (found)
|
|
|
|
|
break;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return found;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static bool check_var_refs(struct hist_trigger_data *hist_data)
|
|
|
|
|
{
|
|
|
|
|
struct hist_field *field;
|
|
|
|
|
bool found = false;
|
|
|
|
|
int i;
|
|
|
|
|
|
|
|
|
|
for_each_hist_field(i, hist_data) {
|
|
|
|
|
field = hist_data->fields[i];
|
|
|
|
|
if (field && field->flags & HIST_FIELD_FL_VAR) {
|
|
|
|
|
if (find_any_var_ref(hist_data, field->var.idx)) {
|
|
|
|
|
found = true;
|
|
|
|
|
break;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return found;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static struct hist_var_data *find_hist_vars(struct hist_trigger_data *hist_data)
|
|
|
|
|
{
|
|
|
|
|
struct trace_array *tr = hist_data->event_file->tr;
|
|
|
|
|
struct hist_var_data *var_data, *found = NULL;
|
|
|
|
|
|
|
|
|
|
list_for_each_entry(var_data, &tr->hist_vars, list) {
|
|
|
|
|
if (var_data->hist_data == hist_data) {
|
|
|
|
|
found = var_data;
|
|
|
|
|
break;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return found;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static bool field_has_hist_vars(struct hist_field *hist_field,
|
|
|
|
|
unsigned int level)
|
|
|
|
|
{
|
|
|
|
|
int i;
|
|
|
|
|
|
|
|
|
|
if (level > 3)
|
|
|
|
|
return false;
|
|
|
|
|
|
|
|
|
|
if (!hist_field)
|
|
|
|
|
return false;
|
|
|
|
|
|
|
|
|
|
if (hist_field->flags & HIST_FIELD_FL_VAR ||
|
|
|
|
|
hist_field->flags & HIST_FIELD_FL_VAR_REF)
|
|
|
|
|
return true;
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < HIST_FIELD_OPERANDS_MAX; i++) {
|
|
|
|
|
struct hist_field *operand;
|
|
|
|
|
|
|
|
|
|
operand = hist_field->operands[i];
|
|
|
|
|
if (field_has_hist_vars(operand, level + 1))
|
|
|
|
|
return true;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return false;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static bool has_hist_vars(struct hist_trigger_data *hist_data)
|
|
|
|
|
{
|
|
|
|
|
struct hist_field *hist_field;
|
|
|
|
|
int i;
|
|
|
|
|
|
|
|
|
|
for_each_hist_field(i, hist_data) {
|
|
|
|
|
hist_field = hist_data->fields[i];
|
|
|
|
|
if (field_has_hist_vars(hist_field, 0))
|
|
|
|
|
return true;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return false;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int save_hist_vars(struct hist_trigger_data *hist_data)
|
|
|
|
|
{
|
|
|
|
|
struct trace_array *tr = hist_data->event_file->tr;
|
|
|
|
|
struct hist_var_data *var_data;
|
|
|
|
|
|
|
|
|
|
var_data = find_hist_vars(hist_data);
|
|
|
|
|
if (var_data)
|
|
|
|
|
return 0;
|
|
|
|
|
|
|
|
|
|
if (trace_array_get(tr) < 0)
|
|
|
|
|
return -ENODEV;
|
|
|
|
|
|
|
|
|
|
var_data = kzalloc(sizeof(*var_data), GFP_KERNEL);
|
|
|
|
|
if (!var_data) {
|
|
|
|
|
trace_array_put(tr);
|
|
|
|
|
return -ENOMEM;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
var_data->hist_data = hist_data;
|
|
|
|
|
list_add(&var_data->list, &tr->hist_vars);
|
|
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void remove_hist_vars(struct hist_trigger_data *hist_data)
|
|
|
|
|
{
|
|
|
|
|
struct trace_array *tr = hist_data->event_file->tr;
|
|
|
|
|
struct hist_var_data *var_data;
|
|
|
|
|
|
|
|
|
|
var_data = find_hist_vars(hist_data);
|
|
|
|
|
if (!var_data)
|
|
|
|
|
return;
|
|
|
|
|
|
|
|
|
|
if (WARN_ON(check_var_refs(hist_data)))
|
|
|
|
|
return;
|
|
|
|
|
|
|
|
|
|
list_del(&var_data->list);
|
|
|
|
|
|
|
|
|
|
kfree(var_data);
|
|
|
|
|
|
|
|
|
|
trace_array_put(tr);
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:51:49 +08:00
|
|
|
static struct hist_field *find_var_field(struct hist_trigger_data *hist_data,
|
|
|
|
|
const char *var_name)
|
|
|
|
|
{
|
|
|
|
|
struct hist_field *hist_field, *found = NULL;
|
|
|
|
|
int i;
|
|
|
|
|
|
|
|
|
|
for_each_hist_field(i, hist_data) {
|
|
|
|
|
hist_field = hist_data->fields[i];
|
|
|
|
|
if (hist_field && hist_field->flags & HIST_FIELD_FL_VAR &&
|
|
|
|
|
strcmp(hist_field->var.name, var_name) == 0) {
|
|
|
|
|
found = hist_field;
|
|
|
|
|
break;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return found;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static struct hist_field *find_var(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct trace_event_file *file,
|
|
|
|
|
const char *var_name)
|
|
|
|
|
{
|
|
|
|
|
struct hist_trigger_data *test_data;
|
|
|
|
|
struct event_trigger_data *test;
|
|
|
|
|
struct hist_field *hist_field;
|
|
|
|
|
|
|
|
|
|
hist_field = find_var_field(hist_data, var_name);
|
|
|
|
|
if (hist_field)
|
|
|
|
|
return hist_field;
|
|
|
|
|
|
|
|
|
|
list_for_each_entry_rcu(test, &file->triggers, list) {
|
|
|
|
|
if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
|
|
|
|
|
test_data = test->private_data;
|
|
|
|
|
hist_field = find_var_field(test_data, var_name);
|
|
|
|
|
if (hist_field)
|
|
|
|
|
return hist_field;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return NULL;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:51:56 +08:00
|
|
|
static struct trace_event_file *find_var_file(struct trace_array *tr,
|
|
|
|
|
char *system,
|
|
|
|
|
char *event_name,
|
|
|
|
|
char *var_name)
|
|
|
|
|
{
|
|
|
|
|
struct hist_trigger_data *var_hist_data;
|
|
|
|
|
struct hist_var_data *var_data;
|
|
|
|
|
struct trace_event_file *file, *found = NULL;
|
|
|
|
|
|
|
|
|
|
if (system)
|
|
|
|
|
return find_event_file(tr, system, event_name);
|
|
|
|
|
|
|
|
|
|
list_for_each_entry(var_data, &tr->hist_vars, list) {
|
|
|
|
|
var_hist_data = var_data->hist_data;
|
|
|
|
|
file = var_hist_data->event_file;
|
|
|
|
|
if (file == found)
|
|
|
|
|
continue;
|
|
|
|
|
|
|
|
|
|
if (find_var_field(var_hist_data, var_name)) {
|
2018-01-16 10:52:05 +08:00
|
|
|
if (found) {
|
|
|
|
|
hist_err_event("Variable name not unique, need to use fully qualified name (subsys.event.var) for variable: ", system, event_name, var_name);
|
2018-01-16 10:51:56 +08:00
|
|
|
return NULL;
|
2018-01-16 10:52:05 +08:00
|
|
|
}
|
2018-01-16 10:51:56 +08:00
|
|
|
|
|
|
|
|
found = file;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return found;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static struct hist_field *find_file_var(struct trace_event_file *file,
|
|
|
|
|
const char *var_name)
|
|
|
|
|
{
|
|
|
|
|
struct hist_trigger_data *test_data;
|
|
|
|
|
struct event_trigger_data *test;
|
|
|
|
|
struct hist_field *hist_field;
|
|
|
|
|
|
|
|
|
|
list_for_each_entry_rcu(test, &file->triggers, list) {
|
|
|
|
|
if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
|
|
|
|
|
test_data = test->private_data;
|
|
|
|
|
hist_field = find_var_field(test_data, var_name);
|
|
|
|
|
if (hist_field)
|
|
|
|
|
return hist_field;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return NULL;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:52:00 +08:00
|
|
|
static struct hist_field *
|
|
|
|
|
find_match_var(struct hist_trigger_data *hist_data, char *var_name)
|
|
|
|
|
{
|
|
|
|
|
struct trace_array *tr = hist_data->event_file->tr;
|
|
|
|
|
struct hist_field *hist_field, *found = NULL;
|
|
|
|
|
struct trace_event_file *file;
|
|
|
|
|
unsigned int i;
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < hist_data->n_actions; i++) {
|
|
|
|
|
struct action_data *data = hist_data->actions[i];
|
|
|
|
|
|
|
|
|
|
if (data->fn == action_trace) {
|
|
|
|
|
char *system = data->onmatch.match_event_system;
|
|
|
|
|
char *event_name = data->onmatch.match_event;
|
|
|
|
|
|
|
|
|
|
file = find_var_file(tr, system, event_name, var_name);
|
|
|
|
|
if (!file)
|
|
|
|
|
continue;
|
|
|
|
|
hist_field = find_file_var(file, var_name);
|
|
|
|
|
if (hist_field) {
|
|
|
|
|
if (found) {
|
2018-01-16 10:52:05 +08:00
|
|
|
hist_err_event("Variable name not unique, need to use fully qualified name (subsys.event.var) for variable: ", system, event_name, var_name);
|
2018-01-16 10:52:00 +08:00
|
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
found = hist_field;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
return found;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:51:56 +08:00
|
|
|
static struct hist_field *find_event_var(struct hist_trigger_data *hist_data,
|
|
|
|
|
char *system,
|
|
|
|
|
char *event_name,
|
|
|
|
|
char *var_name)
|
|
|
|
|
{
|
|
|
|
|
struct trace_array *tr = hist_data->event_file->tr;
|
|
|
|
|
struct hist_field *hist_field = NULL;
|
|
|
|
|
struct trace_event_file *file;
|
|
|
|
|
|
2018-01-16 10:52:00 +08:00
|
|
|
if (!system || !event_name) {
|
|
|
|
|
hist_field = find_match_var(hist_data, var_name);
|
|
|
|
|
if (IS_ERR(hist_field))
|
|
|
|
|
return NULL;
|
|
|
|
|
if (hist_field)
|
|
|
|
|
return hist_field;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:51:56 +08:00
|
|
|
file = find_var_file(tr, system, event_name, var_name);
|
|
|
|
|
if (!file)
|
|
|
|
|
return NULL;
|
|
|
|
|
|
|
|
|
|
hist_field = find_file_var(file, var_name);
|
|
|
|
|
|
|
|
|
|
return hist_field;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:51:53 +08:00
|
|
|
struct hist_elt_data {
|
|
|
|
|
char *comm;
|
2018-01-16 10:51:56 +08:00
|
|
|
u64 *var_ref_vals;
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:51:59 +08:00
|
|
|
char *field_var_str[SYNTH_FIELDS_MAX];
|
2018-01-16 10:51:53 +08:00
|
|
|
};
|
|
|
|
|
|
2018-01-16 10:51:56 +08:00
|
|
|
static u64 hist_field_var_ref(struct hist_field *hist_field,
|
|
|
|
|
struct tracing_map_elt *elt,
|
|
|
|
|
struct ring_buffer_event *rbe,
|
|
|
|
|
void *event)
|
|
|
|
|
{
|
|
|
|
|
struct hist_elt_data *elt_data;
|
|
|
|
|
u64 var_val = 0;
|
|
|
|
|
|
|
|
|
|
elt_data = elt->private_data;
|
|
|
|
|
var_val = elt_data->var_ref_vals[hist_field->var_ref_idx];
|
|
|
|
|
|
|
|
|
|
return var_val;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static bool resolve_var_refs(struct hist_trigger_data *hist_data, void *key,
|
|
|
|
|
u64 *var_ref_vals, bool self)
|
|
|
|
|
{
|
|
|
|
|
struct hist_trigger_data *var_data;
|
|
|
|
|
struct tracing_map_elt *var_elt;
|
|
|
|
|
struct hist_field *hist_field;
|
|
|
|
|
unsigned int i, var_idx;
|
|
|
|
|
bool resolved = true;
|
|
|
|
|
u64 var_val = 0;
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < hist_data->n_var_refs; i++) {
|
|
|
|
|
hist_field = hist_data->var_refs[i];
|
|
|
|
|
var_idx = hist_field->var.idx;
|
|
|
|
|
var_data = hist_field->var.hist_data;
|
|
|
|
|
|
|
|
|
|
if (var_data == NULL) {
|
|
|
|
|
resolved = false;
|
|
|
|
|
break;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if ((self && var_data != hist_data) ||
|
|
|
|
|
(!self && var_data == hist_data))
|
|
|
|
|
continue;
|
|
|
|
|
|
|
|
|
|
var_elt = tracing_map_lookup(var_data->map, key);
|
|
|
|
|
if (!var_elt) {
|
|
|
|
|
resolved = false;
|
|
|
|
|
break;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if (!tracing_map_var_set(var_elt, var_idx)) {
|
|
|
|
|
resolved = false;
|
|
|
|
|
break;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if (self || !hist_field->read_once)
|
|
|
|
|
var_val = tracing_map_read_var(var_elt, var_idx);
|
|
|
|
|
else
|
|
|
|
|
var_val = tracing_map_read_var_once(var_elt, var_idx);
|
|
|
|
|
|
|
|
|
|
var_ref_vals[i] = var_val;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return resolved;
|
|
|
|
|
}
|
|
|
|
|
|
2017-09-23 03:58:22 +08:00
|
|
|
static const char *hist_field_name(struct hist_field *field,
|
|
|
|
|
unsigned int level)
|
|
|
|
|
{
|
|
|
|
|
const char *field_name = "";
|
|
|
|
|
|
|
|
|
|
if (level > 1)
|
|
|
|
|
return field_name;
|
|
|
|
|
|
|
|
|
|
if (field->field)
|
|
|
|
|
field_name = field->field->name;
|
2018-01-16 10:52:04 +08:00
|
|
|
else if (field->flags & HIST_FIELD_FL_LOG2 ||
|
|
|
|
|
field->flags & HIST_FIELD_FL_ALIAS)
|
2017-09-23 03:58:23 +08:00
|
|
|
field_name = hist_field_name(field->operands[0], ++level);
|
2018-01-16 10:51:45 +08:00
|
|
|
else if (field->flags & HIST_FIELD_FL_TIMESTAMP)
|
|
|
|
|
field_name = "common_timestamp";
|
2018-01-16 10:52:03 +08:00
|
|
|
else if (field->flags & HIST_FIELD_FL_CPU)
|
|
|
|
|
field_name = "cpu";
|
2018-01-16 10:51:56 +08:00
|
|
|
else if (field->flags & HIST_FIELD_FL_EXPR ||
|
|
|
|
|
field->flags & HIST_FIELD_FL_VAR_REF) {
|
|
|
|
|
if (field->system) {
|
|
|
|
|
static char full_name[MAX_FILTER_STR_VAL];
|
|
|
|
|
|
|
|
|
|
strcat(full_name, field->system);
|
|
|
|
|
strcat(full_name, ".");
|
|
|
|
|
strcat(full_name, field->event_name);
|
|
|
|
|
strcat(full_name, ".");
|
|
|
|
|
strcat(full_name, field->name);
|
|
|
|
|
field_name = full_name;
|
|
|
|
|
} else
|
|
|
|
|
field_name = field->name;
|
|
|
|
|
}
|
2017-09-23 03:58:22 +08:00
|
|
|
|
|
|
|
|
if (field_name == NULL)
|
|
|
|
|
field_name = "";
|
|
|
|
|
|
|
|
|
|
return field_name;
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
static hist_field_fn_t select_value_fn(int field_size, int field_is_signed)
|
|
|
|
|
{
|
|
|
|
|
hist_field_fn_t fn = NULL;
|
|
|
|
|
|
|
|
|
|
switch (field_size) {
|
|
|
|
|
case 8:
|
|
|
|
|
if (field_is_signed)
|
|
|
|
|
fn = hist_field_s64;
|
|
|
|
|
else
|
|
|
|
|
fn = hist_field_u64;
|
|
|
|
|
break;
|
|
|
|
|
case 4:
|
|
|
|
|
if (field_is_signed)
|
|
|
|
|
fn = hist_field_s32;
|
|
|
|
|
else
|
|
|
|
|
fn = hist_field_u32;
|
|
|
|
|
break;
|
|
|
|
|
case 2:
|
|
|
|
|
if (field_is_signed)
|
|
|
|
|
fn = hist_field_s16;
|
|
|
|
|
else
|
|
|
|
|
fn = hist_field_u16;
|
|
|
|
|
break;
|
|
|
|
|
case 1:
|
|
|
|
|
if (field_is_signed)
|
|
|
|
|
fn = hist_field_s8;
|
|
|
|
|
else
|
|
|
|
|
fn = hist_field_u8;
|
|
|
|
|
break;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return fn;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int parse_map_size(char *str)
|
|
|
|
|
{
|
|
|
|
|
unsigned long size, map_bits;
|
|
|
|
|
int ret;
|
|
|
|
|
|
|
|
|
|
strsep(&str, "=");
|
|
|
|
|
if (!str) {
|
|
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
ret = kstrtoul(str, 0, &size);
|
|
|
|
|
if (ret)
|
|
|
|
|
goto out;
|
|
|
|
|
|
|
|
|
|
map_bits = ilog2(roundup_pow_of_two(size));
|
|
|
|
|
if (map_bits < TRACING_MAP_BITS_MIN ||
|
|
|
|
|
map_bits > TRACING_MAP_BITS_MAX)
|
|
|
|
|
ret = -EINVAL;
|
|
|
|
|
else
|
|
|
|
|
ret = map_bits;
|
|
|
|
|
out:
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void destroy_hist_trigger_attrs(struct hist_trigger_attrs *attrs)
|
|
|
|
|
{
|
2018-01-16 10:51:49 +08:00
|
|
|
unsigned int i;
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
if (!attrs)
|
|
|
|
|
return;
|
|
|
|
|
|
2018-01-16 10:51:49 +08:00
|
|
|
for (i = 0; i < attrs->n_assignments; i++)
|
|
|
|
|
kfree(attrs->assignment_str[i]);
|
|
|
|
|
|
2018-01-16 10:51:57 +08:00
|
|
|
for (i = 0; i < attrs->n_actions; i++)
|
|
|
|
|
kfree(attrs->action_str[i]);
|
|
|
|
|
|
2016-03-04 02:54:59 +08:00
|
|
|
kfree(attrs->name);
|
2016-03-04 02:54:45 +08:00
|
|
|
kfree(attrs->sort_key_str);
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
kfree(attrs->keys_str);
|
2016-03-04 02:54:43 +08:00
|
|
|
kfree(attrs->vals_str);
|
2018-01-16 10:52:08 +08:00
|
|
|
kfree(attrs->clock);
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
kfree(attrs);
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:51:57 +08:00
|
|
|
static int parse_action(char *str, struct hist_trigger_attrs *attrs)
|
|
|
|
|
{
|
2018-01-16 10:52:00 +08:00
|
|
|
int ret = -EINVAL;
|
2018-01-16 10:51:57 +08:00
|
|
|
|
|
|
|
|
if (attrs->n_actions >= HIST_ACTIONS_MAX)
|
|
|
|
|
return ret;
|
|
|
|
|
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:52:01 +08:00
|
|
|
if ((strncmp(str, "onmatch(", strlen("onmatch(")) == 0) ||
|
|
|
|
|
(strncmp(str, "onmax(", strlen("onmax(")) == 0)) {
|
2018-01-16 10:52:00 +08:00
|
|
|
attrs->action_str[attrs->n_actions] = kstrdup(str, GFP_KERNEL);
|
|
|
|
|
if (!attrs->action_str[attrs->n_actions]) {
|
|
|
|
|
ret = -ENOMEM;
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
attrs->n_actions++;
|
|
|
|
|
ret = 0;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:51:57 +08:00
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:51:44 +08:00
|
|
|
static int parse_assignment(char *str, struct hist_trigger_attrs *attrs)
|
|
|
|
|
{
|
|
|
|
|
int ret = 0;
|
|
|
|
|
|
|
|
|
|
if ((strncmp(str, "key=", strlen("key=")) == 0) ||
|
|
|
|
|
(strncmp(str, "keys=", strlen("keys=")) == 0)) {
|
|
|
|
|
attrs->keys_str = kstrdup(str, GFP_KERNEL);
|
|
|
|
|
if (!attrs->keys_str) {
|
|
|
|
|
ret = -ENOMEM;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
} else if ((strncmp(str, "val=", strlen("val=")) == 0) ||
|
|
|
|
|
(strncmp(str, "vals=", strlen("vals=")) == 0) ||
|
|
|
|
|
(strncmp(str, "values=", strlen("values=")) == 0)) {
|
|
|
|
|
attrs->vals_str = kstrdup(str, GFP_KERNEL);
|
|
|
|
|
if (!attrs->vals_str) {
|
|
|
|
|
ret = -ENOMEM;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
} else if (strncmp(str, "sort=", strlen("sort=")) == 0) {
|
|
|
|
|
attrs->sort_key_str = kstrdup(str, GFP_KERNEL);
|
|
|
|
|
if (!attrs->sort_key_str) {
|
|
|
|
|
ret = -ENOMEM;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
} else if (strncmp(str, "name=", strlen("name=")) == 0) {
|
|
|
|
|
attrs->name = kstrdup(str, GFP_KERNEL);
|
|
|
|
|
if (!attrs->name) {
|
|
|
|
|
ret = -ENOMEM;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
2018-01-16 10:52:08 +08:00
|
|
|
} else if (strncmp(str, "clock=", strlen("clock=")) == 0) {
|
|
|
|
|
strsep(&str, "=");
|
|
|
|
|
if (!str) {
|
|
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
str = strstrip(str);
|
|
|
|
|
attrs->clock = kstrdup(str, GFP_KERNEL);
|
|
|
|
|
if (!attrs->clock) {
|
|
|
|
|
ret = -ENOMEM;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
2018-01-16 10:51:44 +08:00
|
|
|
} else if (strncmp(str, "size=", strlen("size=")) == 0) {
|
|
|
|
|
int map_bits = parse_map_size(str);
|
|
|
|
|
|
|
|
|
|
if (map_bits < 0) {
|
|
|
|
|
ret = map_bits;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
attrs->map_bits = map_bits;
|
2018-01-16 10:51:49 +08:00
|
|
|
} else {
|
|
|
|
|
char *assignment;
|
|
|
|
|
|
|
|
|
|
if (attrs->n_assignments == TRACING_MAP_VARS_MAX) {
|
2018-01-16 10:52:05 +08:00
|
|
|
hist_err("Too many variables defined: ", str);
|
2018-01-16 10:51:49 +08:00
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
assignment = kstrdup(str, GFP_KERNEL);
|
|
|
|
|
if (!assignment) {
|
|
|
|
|
ret = -ENOMEM;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
attrs->assignment_str[attrs->n_assignments++] = assignment;
|
|
|
|
|
}
|
2018-01-16 10:51:44 +08:00
|
|
|
out:
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
static struct hist_trigger_attrs *parse_hist_trigger_attrs(char *trigger_str)
|
|
|
|
|
{
|
|
|
|
|
struct hist_trigger_attrs *attrs;
|
|
|
|
|
int ret = 0;
|
|
|
|
|
|
|
|
|
|
attrs = kzalloc(sizeof(*attrs), GFP_KERNEL);
|
|
|
|
|
if (!attrs)
|
|
|
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
|
|
|
|
|
|
while (trigger_str) {
|
|
|
|
|
char *str = strsep(&trigger_str, ":");
|
|
|
|
|
|
2018-01-16 10:51:44 +08:00
|
|
|
if (strchr(str, '=')) {
|
|
|
|
|
ret = parse_assignment(str, attrs);
|
|
|
|
|
if (ret)
|
|
|
|
|
goto free;
|
|
|
|
|
} else if (strcmp(str, "pause") == 0)
|
2016-03-04 02:54:46 +08:00
|
|
|
attrs->pause = true;
|
|
|
|
|
else if ((strcmp(str, "cont") == 0) ||
|
|
|
|
|
(strcmp(str, "continue") == 0))
|
|
|
|
|
attrs->cont = true;
|
2016-03-04 02:54:47 +08:00
|
|
|
else if (strcmp(str, "clear") == 0)
|
|
|
|
|
attrs->clear = true;
|
2018-01-16 10:51:44 +08:00
|
|
|
else {
|
2018-01-16 10:51:57 +08:00
|
|
|
ret = parse_action(str, attrs);
|
|
|
|
|
if (ret)
|
|
|
|
|
goto free;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if (!attrs->keys_str) {
|
|
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:52:08 +08:00
|
|
|
if (!attrs->clock) {
|
|
|
|
|
attrs->clock = kstrdup("global", GFP_KERNEL);
|
|
|
|
|
if (!attrs->clock) {
|
|
|
|
|
ret = -ENOMEM;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
return attrs;
|
|
|
|
|
free:
|
|
|
|
|
destroy_hist_trigger_attrs(attrs);
|
|
|
|
|
|
|
|
|
|
return ERR_PTR(ret);
|
|
|
|
|
}
|
|
|
|
|
|
2016-03-04 02:54:50 +08:00
|
|
|
static inline void save_comm(char *comm, struct task_struct *task)
|
|
|
|
|
{
|
|
|
|
|
if (!task->pid) {
|
|
|
|
|
strcpy(comm, "<idle>");
|
|
|
|
|
return;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if (WARN_ON_ONCE(task->pid < 0)) {
|
|
|
|
|
strcpy(comm, "<XXX>");
|
|
|
|
|
return;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
memcpy(comm, task->comm, TASK_COMM_LEN);
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:51:53 +08:00
|
|
|
static void hist_elt_data_free(struct hist_elt_data *elt_data)
|
|
|
|
|
{
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:51:59 +08:00
|
|
|
unsigned int i;
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < SYNTH_FIELDS_MAX; i++)
|
|
|
|
|
kfree(elt_data->field_var_str[i]);
|
|
|
|
|
|
2018-01-16 10:51:53 +08:00
|
|
|
kfree(elt_data->comm);
|
|
|
|
|
kfree(elt_data);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void hist_trigger_elt_data_free(struct tracing_map_elt *elt)
|
2016-03-04 02:54:50 +08:00
|
|
|
{
|
2018-01-16 10:51:53 +08:00
|
|
|
struct hist_elt_data *elt_data = elt->private_data;
|
|
|
|
|
|
|
|
|
|
hist_elt_data_free(elt_data);
|
2016-03-04 02:54:50 +08:00
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:51:53 +08:00
|
|
|
static int hist_trigger_elt_data_alloc(struct tracing_map_elt *elt)
|
2016-03-04 02:54:50 +08:00
|
|
|
{
|
|
|
|
|
struct hist_trigger_data *hist_data = elt->map->private_data;
|
2018-01-16 10:51:53 +08:00
|
|
|
unsigned int size = TASK_COMM_LEN;
|
|
|
|
|
struct hist_elt_data *elt_data;
|
2016-03-04 02:54:50 +08:00
|
|
|
struct hist_field *key_field;
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:51:59 +08:00
|
|
|
unsigned int i, n_str;
|
2016-03-04 02:54:50 +08:00
|
|
|
|
2018-01-16 10:51:53 +08:00
|
|
|
elt_data = kzalloc(sizeof(*elt_data), GFP_KERNEL);
|
|
|
|
|
if (!elt_data)
|
|
|
|
|
return -ENOMEM;
|
|
|
|
|
|
2016-03-04 02:54:50 +08:00
|
|
|
for_each_hist_key_field(i, hist_data) {
|
|
|
|
|
key_field = hist_data->fields[i];
|
|
|
|
|
|
|
|
|
|
if (key_field->flags & HIST_FIELD_FL_EXECNAME) {
|
2018-01-16 10:51:53 +08:00
|
|
|
elt_data->comm = kzalloc(size, GFP_KERNEL);
|
|
|
|
|
if (!elt_data->comm) {
|
|
|
|
|
kfree(elt_data);
|
2016-03-04 02:54:50 +08:00
|
|
|
return -ENOMEM;
|
2018-01-16 10:51:53 +08:00
|
|
|
}
|
2016-03-04 02:54:50 +08:00
|
|
|
break;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:52:01 +08:00
|
|
|
n_str = hist_data->n_field_var_str + hist_data->n_max_var_str;
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:51:59 +08:00
|
|
|
|
|
|
|
|
size = STR_VAR_LEN_MAX;
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < n_str; i++) {
|
|
|
|
|
elt_data->field_var_str[i] = kzalloc(size, GFP_KERNEL);
|
|
|
|
|
if (!elt_data->field_var_str[i]) {
|
|
|
|
|
hist_elt_data_free(elt_data);
|
|
|
|
|
return -ENOMEM;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:51:53 +08:00
|
|
|
elt->private_data = elt_data;
|
|
|
|
|
|
2016-03-04 02:54:50 +08:00
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:51:53 +08:00
|
|
|
static void hist_trigger_elt_data_init(struct tracing_map_elt *elt)
|
2016-03-04 02:54:50 +08:00
|
|
|
{
|
2018-01-16 10:51:53 +08:00
|
|
|
struct hist_elt_data *elt_data = elt->private_data;
|
2016-03-04 02:54:50 +08:00
|
|
|
|
2018-01-16 10:51:53 +08:00
|
|
|
if (elt_data->comm)
|
|
|
|
|
save_comm(elt_data->comm, current);
|
2016-03-04 02:54:50 +08:00
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:51:53 +08:00
|
|
|
static const struct tracing_map_ops hist_trigger_elt_data_ops = {
|
|
|
|
|
.elt_alloc = hist_trigger_elt_data_alloc,
|
|
|
|
|
.elt_free = hist_trigger_elt_data_free,
|
|
|
|
|
.elt_init = hist_trigger_elt_data_init,
|
2016-03-04 02:54:50 +08:00
|
|
|
};
|
|
|
|
|
|
2018-01-16 10:51:51 +08:00
|
|
|
static const char *get_hist_field_flags(struct hist_field *hist_field)
|
|
|
|
|
{
|
|
|
|
|
const char *flags_str = NULL;
|
|
|
|
|
|
|
|
|
|
if (hist_field->flags & HIST_FIELD_FL_HEX)
|
|
|
|
|
flags_str = "hex";
|
|
|
|
|
else if (hist_field->flags & HIST_FIELD_FL_SYM)
|
|
|
|
|
flags_str = "sym";
|
|
|
|
|
else if (hist_field->flags & HIST_FIELD_FL_SYM_OFFSET)
|
|
|
|
|
flags_str = "sym-offset";
|
|
|
|
|
else if (hist_field->flags & HIST_FIELD_FL_EXECNAME)
|
|
|
|
|
flags_str = "execname";
|
|
|
|
|
else if (hist_field->flags & HIST_FIELD_FL_SYSCALL)
|
|
|
|
|
flags_str = "syscall";
|
|
|
|
|
else if (hist_field->flags & HIST_FIELD_FL_LOG2)
|
|
|
|
|
flags_str = "log2";
|
|
|
|
|
else if (hist_field->flags & HIST_FIELD_FL_TIMESTAMP_USECS)
|
|
|
|
|
flags_str = "usecs";
|
|
|
|
|
|
|
|
|
|
return flags_str;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:51:52 +08:00
|
|
|
static void expr_field_str(struct hist_field *field, char *expr)
|
|
|
|
|
{
|
2018-01-16 10:51:56 +08:00
|
|
|
if (field->flags & HIST_FIELD_FL_VAR_REF)
|
|
|
|
|
strcat(expr, "$");
|
|
|
|
|
|
2018-01-16 10:51:52 +08:00
|
|
|
strcat(expr, hist_field_name(field, 0));
|
|
|
|
|
|
|
|
|
|
if (field->flags) {
|
|
|
|
|
const char *flags_str = get_hist_field_flags(field);
|
|
|
|
|
|
|
|
|
|
if (flags_str) {
|
|
|
|
|
strcat(expr, ".");
|
|
|
|
|
strcat(expr, flags_str);
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static char *expr_str(struct hist_field *field, unsigned int level)
|
|
|
|
|
{
|
|
|
|
|
char *expr;
|
|
|
|
|
|
|
|
|
|
if (level > 1)
|
|
|
|
|
return NULL;
|
|
|
|
|
|
|
|
|
|
expr = kzalloc(MAX_FILTER_STR_VAL, GFP_KERNEL);
|
|
|
|
|
if (!expr)
|
|
|
|
|
return NULL;
|
|
|
|
|
|
|
|
|
|
if (!field->operands[0]) {
|
|
|
|
|
expr_field_str(field, expr);
|
|
|
|
|
return expr;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if (field->operator == FIELD_OP_UNARY_MINUS) {
|
|
|
|
|
char *subexpr;
|
|
|
|
|
|
|
|
|
|
strcat(expr, "-(");
|
|
|
|
|
subexpr = expr_str(field->operands[0], ++level);
|
|
|
|
|
if (!subexpr) {
|
|
|
|
|
kfree(expr);
|
|
|
|
|
return NULL;
|
|
|
|
|
}
|
|
|
|
|
strcat(expr, subexpr);
|
|
|
|
|
strcat(expr, ")");
|
|
|
|
|
|
|
|
|
|
kfree(subexpr);
|
|
|
|
|
|
|
|
|
|
return expr;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
expr_field_str(field->operands[0], expr);
|
|
|
|
|
|
|
|
|
|
switch (field->operator) {
|
|
|
|
|
case FIELD_OP_MINUS:
|
|
|
|
|
strcat(expr, "-");
|
|
|
|
|
break;
|
|
|
|
|
case FIELD_OP_PLUS:
|
|
|
|
|
strcat(expr, "+");
|
|
|
|
|
break;
|
|
|
|
|
default:
|
|
|
|
|
kfree(expr);
|
|
|
|
|
return NULL;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
expr_field_str(field->operands[1], expr);
|
|
|
|
|
|
|
|
|
|
return expr;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int contains_operator(char *str)
|
|
|
|
|
{
|
|
|
|
|
enum field_op_id field_op = FIELD_OP_NONE;
|
|
|
|
|
char *op;
|
|
|
|
|
|
|
|
|
|
op = strpbrk(str, "+-");
|
|
|
|
|
if (!op)
|
|
|
|
|
return FIELD_OP_NONE;
|
|
|
|
|
|
|
|
|
|
switch (*op) {
|
|
|
|
|
case '-':
|
|
|
|
|
if (*str == '-')
|
|
|
|
|
field_op = FIELD_OP_UNARY_MINUS;
|
|
|
|
|
else
|
|
|
|
|
field_op = FIELD_OP_MINUS;
|
|
|
|
|
break;
|
|
|
|
|
case '+':
|
|
|
|
|
field_op = FIELD_OP_PLUS;
|
|
|
|
|
break;
|
|
|
|
|
default:
|
|
|
|
|
break;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return field_op;
|
|
|
|
|
}
|
|
|
|
|
|
2017-09-23 03:58:23 +08:00
|
|
|
static void destroy_hist_field(struct hist_field *hist_field,
|
|
|
|
|
unsigned int level)
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
{
|
2017-09-23 03:58:23 +08:00
|
|
|
unsigned int i;
|
|
|
|
|
|
2018-01-16 10:51:52 +08:00
|
|
|
if (level > 3)
|
2017-09-23 03:58:23 +08:00
|
|
|
return;
|
|
|
|
|
|
|
|
|
|
if (!hist_field)
|
|
|
|
|
return;
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < HIST_FIELD_OPERANDS_MAX; i++)
|
|
|
|
|
destroy_hist_field(hist_field->operands[i], level + 1);
|
|
|
|
|
|
2018-01-16 10:51:49 +08:00
|
|
|
kfree(hist_field->var.name);
|
2018-01-16 10:51:52 +08:00
|
|
|
kfree(hist_field->name);
|
2018-01-16 10:51:55 +08:00
|
|
|
kfree(hist_field->type);
|
2018-01-16 10:51:49 +08:00
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
kfree(hist_field);
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:51:47 +08:00
|
|
|
static struct hist_field *create_hist_field(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct ftrace_event_field *field,
|
2018-01-16 10:51:49 +08:00
|
|
|
unsigned long flags,
|
|
|
|
|
char *var_name)
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
{
|
|
|
|
|
struct hist_field *hist_field;
|
|
|
|
|
|
|
|
|
|
if (field && is_function_field(field))
|
|
|
|
|
return NULL;
|
|
|
|
|
|
|
|
|
|
hist_field = kzalloc(sizeof(struct hist_field), GFP_KERNEL);
|
|
|
|
|
if (!hist_field)
|
|
|
|
|
return NULL;
|
|
|
|
|
|
2018-01-16 10:51:47 +08:00
|
|
|
hist_field->hist_data = hist_data;
|
|
|
|
|
|
2018-01-16 10:52:04 +08:00
|
|
|
if (flags & HIST_FIELD_FL_EXPR || flags & HIST_FIELD_FL_ALIAS)
|
2018-01-16 10:51:52 +08:00
|
|
|
goto out; /* caller will populate */
|
|
|
|
|
|
2018-01-16 10:51:56 +08:00
|
|
|
if (flags & HIST_FIELD_FL_VAR_REF) {
|
|
|
|
|
hist_field->fn = hist_field_var_ref;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
if (flags & HIST_FIELD_FL_HITCOUNT) {
|
|
|
|
|
hist_field->fn = hist_field_counter;
|
2018-01-16 10:51:55 +08:00
|
|
|
hist_field->size = sizeof(u64);
|
|
|
|
|
hist_field->type = kstrdup("u64", GFP_KERNEL);
|
|
|
|
|
if (!hist_field->type)
|
|
|
|
|
goto free;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
2016-03-04 02:54:52 +08:00
|
|
|
if (flags & HIST_FIELD_FL_STACKTRACE) {
|
|
|
|
|
hist_field->fn = hist_field_none;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
2016-03-04 02:55:02 +08:00
|
|
|
if (flags & HIST_FIELD_FL_LOG2) {
|
2017-09-23 03:58:23 +08:00
|
|
|
unsigned long fl = flags & ~HIST_FIELD_FL_LOG2;
|
2016-03-04 02:55:02 +08:00
|
|
|
hist_field->fn = hist_field_log2;
|
2018-01-16 10:51:49 +08:00
|
|
|
hist_field->operands[0] = create_hist_field(hist_data, field, fl, NULL);
|
2017-09-23 03:58:23 +08:00
|
|
|
hist_field->size = hist_field->operands[0]->size;
|
2018-01-16 10:51:55 +08:00
|
|
|
hist_field->type = kstrdup(hist_field->operands[0]->type, GFP_KERNEL);
|
|
|
|
|
if (!hist_field->type)
|
|
|
|
|
goto free;
|
2016-03-04 02:55:02 +08:00
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:51:45 +08:00
|
|
|
if (flags & HIST_FIELD_FL_TIMESTAMP) {
|
|
|
|
|
hist_field->fn = hist_field_timestamp;
|
|
|
|
|
hist_field->size = sizeof(u64);
|
2018-01-16 10:51:55 +08:00
|
|
|
hist_field->type = kstrdup("u64", GFP_KERNEL);
|
|
|
|
|
if (!hist_field->type)
|
|
|
|
|
goto free;
|
2018-01-16 10:51:45 +08:00
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:52:03 +08:00
|
|
|
if (flags & HIST_FIELD_FL_CPU) {
|
|
|
|
|
hist_field->fn = hist_field_cpu;
|
|
|
|
|
hist_field->size = sizeof(int);
|
|
|
|
|
hist_field->type = kstrdup("unsigned int", GFP_KERNEL);
|
|
|
|
|
if (!hist_field->type)
|
|
|
|
|
goto free;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
2016-04-26 03:01:27 +08:00
|
|
|
if (WARN_ON_ONCE(!field))
|
|
|
|
|
goto out;
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
if (is_string_field(field)) {
|
|
|
|
|
flags |= HIST_FIELD_FL_STRING;
|
2016-03-04 02:54:53 +08:00
|
|
|
|
2018-01-16 10:51:55 +08:00
|
|
|
hist_field->size = MAX_FILTER_STR_VAL;
|
|
|
|
|
hist_field->type = kstrdup(field->type, GFP_KERNEL);
|
|
|
|
|
if (!hist_field->type)
|
|
|
|
|
goto free;
|
|
|
|
|
|
2016-03-04 02:54:53 +08:00
|
|
|
if (field->filter_type == FILTER_STATIC_STRING)
|
|
|
|
|
hist_field->fn = hist_field_string;
|
|
|
|
|
else if (field->filter_type == FILTER_DYN_STRING)
|
|
|
|
|
hist_field->fn = hist_field_dynstring;
|
|
|
|
|
else
|
|
|
|
|
hist_field->fn = hist_field_pstring;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
} else {
|
2018-01-16 10:51:55 +08:00
|
|
|
hist_field->size = field->size;
|
|
|
|
|
hist_field->is_signed = field->is_signed;
|
|
|
|
|
hist_field->type = kstrdup(field->type, GFP_KERNEL);
|
|
|
|
|
if (!hist_field->type)
|
|
|
|
|
goto free;
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
hist_field->fn = select_value_fn(field->size,
|
|
|
|
|
field->is_signed);
|
|
|
|
|
if (!hist_field->fn) {
|
2017-09-23 03:58:23 +08:00
|
|
|
destroy_hist_field(hist_field, 0);
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
return NULL;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
out:
|
|
|
|
|
hist_field->field = field;
|
|
|
|
|
hist_field->flags = flags;
|
|
|
|
|
|
2018-01-16 10:51:49 +08:00
|
|
|
if (var_name) {
|
|
|
|
|
hist_field->var.name = kstrdup(var_name, GFP_KERNEL);
|
|
|
|
|
if (!hist_field->var.name)
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
return hist_field;
|
2018-01-16 10:51:49 +08:00
|
|
|
free:
|
|
|
|
|
destroy_hist_field(hist_field, 0);
|
|
|
|
|
return NULL;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void destroy_hist_fields(struct hist_trigger_data *hist_data)
|
|
|
|
|
{
|
|
|
|
|
unsigned int i;
|
|
|
|
|
|
2018-01-16 10:51:49 +08:00
|
|
|
for (i = 0; i < HIST_FIELDS_MAX; i++) {
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
if (hist_data->fields[i]) {
|
2017-09-23 03:58:23 +08:00
|
|
|
destroy_hist_field(hist_data->fields[i], 0);
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
hist_data->fields[i] = NULL;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:51:56 +08:00
|
|
|
static int init_var_ref(struct hist_field *ref_field,
|
|
|
|
|
struct hist_field *var_field,
|
|
|
|
|
char *system, char *event_name)
|
|
|
|
|
{
|
|
|
|
|
int err = 0;
|
|
|
|
|
|
|
|
|
|
ref_field->var.idx = var_field->var.idx;
|
|
|
|
|
ref_field->var.hist_data = var_field->hist_data;
|
|
|
|
|
ref_field->size = var_field->size;
|
|
|
|
|
ref_field->is_signed = var_field->is_signed;
|
|
|
|
|
ref_field->flags |= var_field->flags &
|
|
|
|
|
(HIST_FIELD_FL_TIMESTAMP | HIST_FIELD_FL_TIMESTAMP_USECS);
|
|
|
|
|
|
|
|
|
|
if (system) {
|
|
|
|
|
ref_field->system = kstrdup(system, GFP_KERNEL);
|
|
|
|
|
if (!ref_field->system)
|
|
|
|
|
return -ENOMEM;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if (event_name) {
|
|
|
|
|
ref_field->event_name = kstrdup(event_name, GFP_KERNEL);
|
|
|
|
|
if (!ref_field->event_name) {
|
|
|
|
|
err = -ENOMEM;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:52:04 +08:00
|
|
|
if (var_field->var.name) {
|
|
|
|
|
ref_field->name = kstrdup(var_field->var.name, GFP_KERNEL);
|
|
|
|
|
if (!ref_field->name) {
|
|
|
|
|
err = -ENOMEM;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
|
|
|
|
} else if (var_field->name) {
|
|
|
|
|
ref_field->name = kstrdup(var_field->name, GFP_KERNEL);
|
|
|
|
|
if (!ref_field->name) {
|
|
|
|
|
err = -ENOMEM;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
2018-01-16 10:51:56 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
ref_field->type = kstrdup(var_field->type, GFP_KERNEL);
|
|
|
|
|
if (!ref_field->type) {
|
|
|
|
|
err = -ENOMEM;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
|
|
|
|
out:
|
|
|
|
|
return err;
|
|
|
|
|
free:
|
|
|
|
|
kfree(ref_field->system);
|
|
|
|
|
kfree(ref_field->event_name);
|
|
|
|
|
kfree(ref_field->name);
|
|
|
|
|
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static struct hist_field *create_var_ref(struct hist_field *var_field,
|
|
|
|
|
char *system, char *event_name)
|
|
|
|
|
{
|
|
|
|
|
unsigned long flags = HIST_FIELD_FL_VAR_REF;
|
|
|
|
|
struct hist_field *ref_field;
|
|
|
|
|
|
|
|
|
|
ref_field = create_hist_field(var_field->hist_data, NULL, flags, NULL);
|
|
|
|
|
if (ref_field) {
|
|
|
|
|
if (init_var_ref(ref_field, var_field, system, event_name)) {
|
|
|
|
|
destroy_hist_field(ref_field, 0);
|
|
|
|
|
return NULL;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return ref_field;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static bool is_var_ref(char *var_name)
|
|
|
|
|
{
|
|
|
|
|
if (!var_name || strlen(var_name) < 2 || var_name[0] != '$')
|
|
|
|
|
return false;
|
|
|
|
|
|
|
|
|
|
return true;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static char *field_name_from_var(struct hist_trigger_data *hist_data,
|
|
|
|
|
char *var_name)
|
|
|
|
|
{
|
|
|
|
|
char *name, *field;
|
|
|
|
|
unsigned int i;
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < hist_data->attrs->var_defs.n_vars; i++) {
|
|
|
|
|
name = hist_data->attrs->var_defs.name[i];
|
|
|
|
|
|
|
|
|
|
if (strcmp(var_name, name) == 0) {
|
|
|
|
|
field = hist_data->attrs->var_defs.expr[i];
|
|
|
|
|
if (contains_operator(field) || is_var_ref(field))
|
|
|
|
|
continue;
|
|
|
|
|
return field;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return NULL;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static char *local_field_var_ref(struct hist_trigger_data *hist_data,
|
|
|
|
|
char *system, char *event_name,
|
|
|
|
|
char *var_name)
|
|
|
|
|
{
|
|
|
|
|
struct trace_event_call *call;
|
|
|
|
|
|
|
|
|
|
if (system && event_name) {
|
|
|
|
|
call = hist_data->event_file->event_call;
|
|
|
|
|
|
|
|
|
|
if (strcmp(system, call->class->system) != 0)
|
|
|
|
|
return NULL;
|
|
|
|
|
|
|
|
|
|
if (strcmp(event_name, trace_event_name(call)) != 0)
|
|
|
|
|
return NULL;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if (!!system != !!event_name)
|
|
|
|
|
return NULL;
|
|
|
|
|
|
|
|
|
|
if (!is_var_ref(var_name))
|
|
|
|
|
return NULL;
|
|
|
|
|
|
|
|
|
|
var_name++;
|
|
|
|
|
|
|
|
|
|
return field_name_from_var(hist_data, var_name);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static struct hist_field *parse_var_ref(struct hist_trigger_data *hist_data,
|
|
|
|
|
char *system, char *event_name,
|
|
|
|
|
char *var_name)
|
|
|
|
|
{
|
|
|
|
|
struct hist_field *var_field = NULL, *ref_field = NULL;
|
|
|
|
|
|
|
|
|
|
if (!is_var_ref(var_name))
|
|
|
|
|
return NULL;
|
|
|
|
|
|
|
|
|
|
var_name++;
|
|
|
|
|
|
|
|
|
|
var_field = find_event_var(hist_data, system, event_name, var_name);
|
|
|
|
|
if (var_field)
|
|
|
|
|
ref_field = create_var_ref(var_field, system, event_name);
|
|
|
|
|
|
2018-01-16 10:52:05 +08:00
|
|
|
if (!ref_field)
|
|
|
|
|
hist_err_event("Couldn't find variable: $",
|
|
|
|
|
system, event_name, var_name);
|
|
|
|
|
|
2018-01-16 10:51:56 +08:00
|
|
|
return ref_field;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:51:52 +08:00
|
|
|
static struct ftrace_event_field *
|
|
|
|
|
parse_field(struct hist_trigger_data *hist_data, struct trace_event_file *file,
|
|
|
|
|
char *field_str, unsigned long *flags)
|
|
|
|
|
{
|
|
|
|
|
struct ftrace_event_field *field = NULL;
|
|
|
|
|
char *field_name, *modifier, *str;
|
|
|
|
|
|
|
|
|
|
modifier = str = kstrdup(field_str, GFP_KERNEL);
|
|
|
|
|
if (!modifier)
|
|
|
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
|
|
|
|
|
|
field_name = strsep(&modifier, ".");
|
|
|
|
|
if (modifier) {
|
|
|
|
|
if (strcmp(modifier, "hex") == 0)
|
|
|
|
|
*flags |= HIST_FIELD_FL_HEX;
|
|
|
|
|
else if (strcmp(modifier, "sym") == 0)
|
|
|
|
|
*flags |= HIST_FIELD_FL_SYM;
|
|
|
|
|
else if (strcmp(modifier, "sym-offset") == 0)
|
|
|
|
|
*flags |= HIST_FIELD_FL_SYM_OFFSET;
|
|
|
|
|
else if ((strcmp(modifier, "execname") == 0) &&
|
|
|
|
|
(strcmp(field_name, "common_pid") == 0))
|
|
|
|
|
*flags |= HIST_FIELD_FL_EXECNAME;
|
|
|
|
|
else if (strcmp(modifier, "syscall") == 0)
|
|
|
|
|
*flags |= HIST_FIELD_FL_SYSCALL;
|
|
|
|
|
else if (strcmp(modifier, "log2") == 0)
|
|
|
|
|
*flags |= HIST_FIELD_FL_LOG2;
|
|
|
|
|
else if (strcmp(modifier, "usecs") == 0)
|
|
|
|
|
*flags |= HIST_FIELD_FL_TIMESTAMP_USECS;
|
|
|
|
|
else {
|
|
|
|
|
field = ERR_PTR(-EINVAL);
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if (strcmp(field_name, "common_timestamp") == 0) {
|
|
|
|
|
*flags |= HIST_FIELD_FL_TIMESTAMP;
|
|
|
|
|
hist_data->enable_timestamps = true;
|
|
|
|
|
if (*flags & HIST_FIELD_FL_TIMESTAMP_USECS)
|
|
|
|
|
hist_data->attrs->ts_in_usecs = true;
|
2018-01-16 10:52:03 +08:00
|
|
|
} else if (strcmp(field_name, "cpu") == 0)
|
|
|
|
|
*flags |= HIST_FIELD_FL_CPU;
|
|
|
|
|
else {
|
2018-01-16 10:51:52 +08:00
|
|
|
field = trace_find_event_field(file->event_call, field_name);
|
|
|
|
|
if (!field || !field->size) {
|
|
|
|
|
field = ERR_PTR(-EINVAL);
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
out:
|
|
|
|
|
kfree(str);
|
|
|
|
|
|
|
|
|
|
return field;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:52:04 +08:00
|
|
|
static struct hist_field *create_alias(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct hist_field *var_ref,
|
|
|
|
|
char *var_name)
|
|
|
|
|
{
|
|
|
|
|
struct hist_field *alias = NULL;
|
|
|
|
|
unsigned long flags = HIST_FIELD_FL_ALIAS | HIST_FIELD_FL_VAR;
|
|
|
|
|
|
|
|
|
|
alias = create_hist_field(hist_data, NULL, flags, var_name);
|
|
|
|
|
if (!alias)
|
|
|
|
|
return NULL;
|
|
|
|
|
|
|
|
|
|
alias->fn = var_ref->fn;
|
|
|
|
|
alias->operands[0] = var_ref;
|
|
|
|
|
|
|
|
|
|
if (init_var_ref(alias, var_ref, var_ref->system, var_ref->event_name)) {
|
|
|
|
|
destroy_hist_field(alias, 0);
|
|
|
|
|
return NULL;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return alias;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:51:52 +08:00
|
|
|
static struct hist_field *parse_atom(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct trace_event_file *file, char *str,
|
|
|
|
|
unsigned long *flags, char *var_name)
|
|
|
|
|
{
|
2018-01-16 10:51:56 +08:00
|
|
|
char *s, *ref_system = NULL, *ref_event = NULL, *ref_var = str;
|
2018-01-16 10:51:52 +08:00
|
|
|
struct ftrace_event_field *field = NULL;
|
|
|
|
|
struct hist_field *hist_field = NULL;
|
|
|
|
|
int ret = 0;
|
|
|
|
|
|
2018-01-16 10:51:56 +08:00
|
|
|
s = strchr(str, '.');
|
|
|
|
|
if (s) {
|
|
|
|
|
s = strchr(++s, '.');
|
|
|
|
|
if (s) {
|
|
|
|
|
ref_system = strsep(&str, ".");
|
|
|
|
|
if (!str) {
|
|
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
ref_event = strsep(&str, ".");
|
|
|
|
|
if (!str) {
|
|
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
ref_var = str;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
s = local_field_var_ref(hist_data, ref_system, ref_event, ref_var);
|
|
|
|
|
if (!s) {
|
|
|
|
|
hist_field = parse_var_ref(hist_data, ref_system, ref_event, ref_var);
|
|
|
|
|
if (hist_field) {
|
|
|
|
|
hist_data->var_refs[hist_data->n_var_refs] = hist_field;
|
|
|
|
|
hist_field->var_ref_idx = hist_data->n_var_refs++;
|
2018-01-16 10:52:04 +08:00
|
|
|
if (var_name) {
|
|
|
|
|
hist_field = create_alias(hist_data, hist_field, var_name);
|
|
|
|
|
if (!hist_field) {
|
|
|
|
|
ret = -ENOMEM;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
}
|
2018-01-16 10:51:56 +08:00
|
|
|
return hist_field;
|
|
|
|
|
}
|
|
|
|
|
} else
|
|
|
|
|
str = s;
|
|
|
|
|
|
2018-01-16 10:51:52 +08:00
|
|
|
field = parse_field(hist_data, file, str, flags);
|
|
|
|
|
if (IS_ERR(field)) {
|
|
|
|
|
ret = PTR_ERR(field);
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
hist_field = create_hist_field(hist_data, field, *flags, var_name);
|
|
|
|
|
if (!hist_field) {
|
|
|
|
|
ret = -ENOMEM;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return hist_field;
|
|
|
|
|
out:
|
|
|
|
|
return ERR_PTR(ret);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static struct hist_field *parse_expr(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct trace_event_file *file,
|
|
|
|
|
char *str, unsigned long flags,
|
|
|
|
|
char *var_name, unsigned int level);
|
|
|
|
|
|
|
|
|
|
static struct hist_field *parse_unary(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct trace_event_file *file,
|
|
|
|
|
char *str, unsigned long flags,
|
|
|
|
|
char *var_name, unsigned int level)
|
|
|
|
|
{
|
|
|
|
|
struct hist_field *operand1, *expr = NULL;
|
|
|
|
|
unsigned long operand_flags;
|
|
|
|
|
int ret = 0;
|
|
|
|
|
char *s;
|
|
|
|
|
|
|
|
|
|
/* we support only -(xxx) i.e. explicit parens required */
|
|
|
|
|
|
|
|
|
|
if (level > 3) {
|
2018-01-16 10:52:05 +08:00
|
|
|
hist_err("Too many subexpressions (3 max): ", str);
|
2018-01-16 10:51:52 +08:00
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
str++; /* skip leading '-' */
|
|
|
|
|
|
|
|
|
|
s = strchr(str, '(');
|
|
|
|
|
if (s)
|
|
|
|
|
str++;
|
|
|
|
|
else {
|
|
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
s = strrchr(str, ')');
|
|
|
|
|
if (s)
|
|
|
|
|
*s = '\0';
|
|
|
|
|
else {
|
|
|
|
|
ret = -EINVAL; /* no closing ')' */
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
flags |= HIST_FIELD_FL_EXPR;
|
|
|
|
|
expr = create_hist_field(hist_data, NULL, flags, var_name);
|
|
|
|
|
if (!expr) {
|
|
|
|
|
ret = -ENOMEM;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
operand_flags = 0;
|
|
|
|
|
operand1 = parse_expr(hist_data, file, str, operand_flags, NULL, ++level);
|
|
|
|
|
if (IS_ERR(operand1)) {
|
|
|
|
|
ret = PTR_ERR(operand1);
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
expr->flags |= operand1->flags &
|
|
|
|
|
(HIST_FIELD_FL_TIMESTAMP | HIST_FIELD_FL_TIMESTAMP_USECS);
|
|
|
|
|
expr->fn = hist_field_unary_minus;
|
|
|
|
|
expr->operands[0] = operand1;
|
|
|
|
|
expr->operator = FIELD_OP_UNARY_MINUS;
|
|
|
|
|
expr->name = expr_str(expr, 0);
|
2018-01-16 10:51:55 +08:00
|
|
|
expr->type = kstrdup(operand1->type, GFP_KERNEL);
|
|
|
|
|
if (!expr->type) {
|
|
|
|
|
ret = -ENOMEM;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
2018-01-16 10:51:52 +08:00
|
|
|
|
|
|
|
|
return expr;
|
|
|
|
|
free:
|
|
|
|
|
destroy_hist_field(expr, 0);
|
|
|
|
|
return ERR_PTR(ret);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int check_expr_operands(struct hist_field *operand1,
|
|
|
|
|
struct hist_field *operand2)
|
|
|
|
|
{
|
|
|
|
|
unsigned long operand1_flags = operand1->flags;
|
|
|
|
|
unsigned long operand2_flags = operand2->flags;
|
|
|
|
|
|
2018-01-16 10:52:04 +08:00
|
|
|
if ((operand1_flags & HIST_FIELD_FL_VAR_REF) ||
|
|
|
|
|
(operand1_flags & HIST_FIELD_FL_ALIAS)) {
|
|
|
|
|
struct hist_field *var;
|
|
|
|
|
|
|
|
|
|
var = find_var_field(operand1->var.hist_data, operand1->name);
|
|
|
|
|
if (!var)
|
|
|
|
|
return -EINVAL;
|
|
|
|
|
operand1_flags = var->flags;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if ((operand2_flags & HIST_FIELD_FL_VAR_REF) ||
|
|
|
|
|
(operand2_flags & HIST_FIELD_FL_ALIAS)) {
|
|
|
|
|
struct hist_field *var;
|
|
|
|
|
|
|
|
|
|
var = find_var_field(operand2->var.hist_data, operand2->name);
|
|
|
|
|
if (!var)
|
|
|
|
|
return -EINVAL;
|
|
|
|
|
operand2_flags = var->flags;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:51:52 +08:00
|
|
|
if ((operand1_flags & HIST_FIELD_FL_TIMESTAMP_USECS) !=
|
2018-01-16 10:52:05 +08:00
|
|
|
(operand2_flags & HIST_FIELD_FL_TIMESTAMP_USECS)) {
|
|
|
|
|
hist_err("Timestamp units in expression don't match", NULL);
|
2018-01-16 10:51:52 +08:00
|
|
|
return -EINVAL;
|
2018-01-16 10:52:05 +08:00
|
|
|
}
|
2018-01-16 10:51:52 +08:00
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static struct hist_field *parse_expr(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct trace_event_file *file,
|
|
|
|
|
char *str, unsigned long flags,
|
|
|
|
|
char *var_name, unsigned int level)
|
|
|
|
|
{
|
|
|
|
|
struct hist_field *operand1 = NULL, *operand2 = NULL, *expr = NULL;
|
|
|
|
|
unsigned long operand_flags;
|
|
|
|
|
int field_op, ret = -EINVAL;
|
|
|
|
|
char *sep, *operand1_str;
|
|
|
|
|
|
2018-01-16 10:52:05 +08:00
|
|
|
if (level > 3) {
|
|
|
|
|
hist_err("Too many subexpressions (3 max): ", str);
|
2018-01-16 10:51:52 +08:00
|
|
|
return ERR_PTR(-EINVAL);
|
2018-01-16 10:52:05 +08:00
|
|
|
}
|
2018-01-16 10:51:52 +08:00
|
|
|
|
|
|
|
|
field_op = contains_operator(str);
|
|
|
|
|
|
|
|
|
|
if (field_op == FIELD_OP_NONE)
|
|
|
|
|
return parse_atom(hist_data, file, str, &flags, var_name);
|
|
|
|
|
|
|
|
|
|
if (field_op == FIELD_OP_UNARY_MINUS)
|
|
|
|
|
return parse_unary(hist_data, file, str, flags, var_name, ++level);
|
|
|
|
|
|
|
|
|
|
switch (field_op) {
|
|
|
|
|
case FIELD_OP_MINUS:
|
|
|
|
|
sep = "-";
|
|
|
|
|
break;
|
|
|
|
|
case FIELD_OP_PLUS:
|
|
|
|
|
sep = "+";
|
|
|
|
|
break;
|
|
|
|
|
default:
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
operand1_str = strsep(&str, sep);
|
|
|
|
|
if (!operand1_str || !str)
|
|
|
|
|
goto free;
|
|
|
|
|
|
|
|
|
|
operand_flags = 0;
|
|
|
|
|
operand1 = parse_atom(hist_data, file, operand1_str,
|
|
|
|
|
&operand_flags, NULL);
|
|
|
|
|
if (IS_ERR(operand1)) {
|
|
|
|
|
ret = PTR_ERR(operand1);
|
|
|
|
|
operand1 = NULL;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/* rest of string could be another expression e.g. b+c in a+b+c */
|
|
|
|
|
operand_flags = 0;
|
|
|
|
|
operand2 = parse_expr(hist_data, file, str, operand_flags, NULL, ++level);
|
|
|
|
|
if (IS_ERR(operand2)) {
|
|
|
|
|
ret = PTR_ERR(operand2);
|
|
|
|
|
operand2 = NULL;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
ret = check_expr_operands(operand1, operand2);
|
|
|
|
|
if (ret)
|
|
|
|
|
goto free;
|
|
|
|
|
|
|
|
|
|
flags |= HIST_FIELD_FL_EXPR;
|
|
|
|
|
|
|
|
|
|
flags |= operand1->flags &
|
|
|
|
|
(HIST_FIELD_FL_TIMESTAMP | HIST_FIELD_FL_TIMESTAMP_USECS);
|
|
|
|
|
|
|
|
|
|
expr = create_hist_field(hist_data, NULL, flags, var_name);
|
|
|
|
|
if (!expr) {
|
|
|
|
|
ret = -ENOMEM;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:51:56 +08:00
|
|
|
operand1->read_once = true;
|
|
|
|
|
operand2->read_once = true;
|
|
|
|
|
|
2018-01-16 10:51:52 +08:00
|
|
|
expr->operands[0] = operand1;
|
|
|
|
|
expr->operands[1] = operand2;
|
|
|
|
|
expr->operator = field_op;
|
|
|
|
|
expr->name = expr_str(expr, 0);
|
2018-01-16 10:51:55 +08:00
|
|
|
expr->type = kstrdup(operand1->type, GFP_KERNEL);
|
|
|
|
|
if (!expr->type) {
|
|
|
|
|
ret = -ENOMEM;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
2018-01-16 10:51:52 +08:00
|
|
|
|
|
|
|
|
switch (field_op) {
|
|
|
|
|
case FIELD_OP_MINUS:
|
|
|
|
|
expr->fn = hist_field_minus;
|
|
|
|
|
break;
|
|
|
|
|
case FIELD_OP_PLUS:
|
|
|
|
|
expr->fn = hist_field_plus;
|
|
|
|
|
break;
|
|
|
|
|
default:
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return expr;
|
|
|
|
|
free:
|
|
|
|
|
destroy_hist_field(operand1, 0);
|
|
|
|
|
destroy_hist_field(operand2, 0);
|
|
|
|
|
destroy_hist_field(expr, 0);
|
|
|
|
|
|
|
|
|
|
return ERR_PTR(ret);
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:51:59 +08:00
|
|
|
static char *find_trigger_filter(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct trace_event_file *file)
|
|
|
|
|
{
|
|
|
|
|
struct event_trigger_data *test;
|
|
|
|
|
|
|
|
|
|
list_for_each_entry_rcu(test, &file->triggers, list) {
|
|
|
|
|
if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
|
|
|
|
|
if (test->private_data == hist_data)
|
|
|
|
|
return test->filter_str;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return NULL;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static struct event_command trigger_hist_cmd;
|
|
|
|
|
static int event_hist_trigger_func(struct event_command *cmd_ops,
|
|
|
|
|
struct trace_event_file *file,
|
|
|
|
|
char *glob, char *cmd, char *param);
|
|
|
|
|
|
|
|
|
|
static bool compatible_keys(struct hist_trigger_data *target_hist_data,
|
|
|
|
|
struct hist_trigger_data *hist_data,
|
|
|
|
|
unsigned int n_keys)
|
|
|
|
|
{
|
|
|
|
|
struct hist_field *target_hist_field, *hist_field;
|
|
|
|
|
unsigned int n, i, j;
|
|
|
|
|
|
|
|
|
|
if (hist_data->n_fields - hist_data->n_vals != n_keys)
|
|
|
|
|
return false;
|
|
|
|
|
|
|
|
|
|
i = hist_data->n_vals;
|
|
|
|
|
j = target_hist_data->n_vals;
|
|
|
|
|
|
|
|
|
|
for (n = 0; n < n_keys; n++) {
|
|
|
|
|
hist_field = hist_data->fields[i + n];
|
|
|
|
|
target_hist_field = target_hist_data->fields[j + n];
|
|
|
|
|
|
|
|
|
|
if (strcmp(hist_field->type, target_hist_field->type) != 0)
|
|
|
|
|
return false;
|
|
|
|
|
if (hist_field->size != target_hist_field->size)
|
|
|
|
|
return false;
|
|
|
|
|
if (hist_field->is_signed != target_hist_field->is_signed)
|
|
|
|
|
return false;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return true;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static struct hist_trigger_data *
|
|
|
|
|
find_compatible_hist(struct hist_trigger_data *target_hist_data,
|
|
|
|
|
struct trace_event_file *file)
|
|
|
|
|
{
|
|
|
|
|
struct hist_trigger_data *hist_data;
|
|
|
|
|
struct event_trigger_data *test;
|
|
|
|
|
unsigned int n_keys;
|
|
|
|
|
|
|
|
|
|
n_keys = target_hist_data->n_fields - target_hist_data->n_vals;
|
|
|
|
|
|
|
|
|
|
list_for_each_entry_rcu(test, &file->triggers, list) {
|
|
|
|
|
if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
|
|
|
|
|
hist_data = test->private_data;
|
|
|
|
|
|
|
|
|
|
if (compatible_keys(target_hist_data, hist_data, n_keys))
|
|
|
|
|
return hist_data;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return NULL;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static struct trace_event_file *event_file(struct trace_array *tr,
|
|
|
|
|
char *system, char *event_name)
|
|
|
|
|
{
|
|
|
|
|
struct trace_event_file *file;
|
|
|
|
|
|
|
|
|
|
file = find_event_file(tr, system, event_name);
|
|
|
|
|
if (!file)
|
|
|
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
|
|
|
|
|
|
return file;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static struct hist_field *
|
|
|
|
|
find_synthetic_field_var(struct hist_trigger_data *target_hist_data,
|
|
|
|
|
char *system, char *event_name, char *field_name)
|
|
|
|
|
{
|
|
|
|
|
struct hist_field *event_var;
|
|
|
|
|
char *synthetic_name;
|
|
|
|
|
|
|
|
|
|
synthetic_name = kzalloc(MAX_FILTER_STR_VAL, GFP_KERNEL);
|
|
|
|
|
if (!synthetic_name)
|
|
|
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
|
|
|
|
|
|
strcpy(synthetic_name, "synthetic_");
|
|
|
|
|
strcat(synthetic_name, field_name);
|
|
|
|
|
|
|
|
|
|
event_var = find_event_var(target_hist_data, system, event_name, synthetic_name);
|
|
|
|
|
|
|
|
|
|
kfree(synthetic_name);
|
|
|
|
|
|
|
|
|
|
return event_var;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/**
|
|
|
|
|
* create_field_var_hist - Automatically create a histogram and var for a field
|
|
|
|
|
* @target_hist_data: The target hist trigger
|
|
|
|
|
* @subsys_name: Optional subsystem name
|
|
|
|
|
* @event_name: Optional event name
|
|
|
|
|
* @field_name: The name of the field (and the resulting variable)
|
|
|
|
|
*
|
|
|
|
|
* Hist trigger actions fetch data from variables, not directly from
|
|
|
|
|
* events. However, for convenience, users are allowed to directly
|
|
|
|
|
* specify an event field in an action, which will be automatically
|
|
|
|
|
* converted into a variable on their behalf.
|
|
|
|
|
|
|
|
|
|
* If a user specifies a field on an event that isn't the event the
|
|
|
|
|
* histogram currently being defined (the target event histogram), the
|
|
|
|
|
* only way that can be accomplished is if a new hist trigger is
|
|
|
|
|
* created and the field variable defined on that.
|
|
|
|
|
*
|
|
|
|
|
* This function creates a new histogram compatible with the target
|
|
|
|
|
* event (meaning a histogram with the same key as the target
|
|
|
|
|
* histogram), and creates a variable for the specified field, but
|
|
|
|
|
* with 'synthetic_' prepended to the variable name in order to avoid
|
|
|
|
|
* collision with normal field variables.
|
|
|
|
|
*
|
|
|
|
|
* Return: The variable created for the field.
|
|
|
|
|
*/
|
2018-01-16 10:52:00 +08:00
|
|
|
static struct hist_field *
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:51:59 +08:00
|
|
|
create_field_var_hist(struct hist_trigger_data *target_hist_data,
|
|
|
|
|
char *subsys_name, char *event_name, char *field_name)
|
|
|
|
|
{
|
|
|
|
|
struct trace_array *tr = target_hist_data->event_file->tr;
|
|
|
|
|
struct hist_field *event_var = ERR_PTR(-EINVAL);
|
|
|
|
|
struct hist_trigger_data *hist_data;
|
|
|
|
|
unsigned int i, n, first = true;
|
|
|
|
|
struct field_var_hist *var_hist;
|
|
|
|
|
struct trace_event_file *file;
|
|
|
|
|
struct hist_field *key_field;
|
|
|
|
|
char *saved_filter;
|
|
|
|
|
char *cmd;
|
|
|
|
|
int ret;
|
|
|
|
|
|
2018-01-16 10:52:05 +08:00
|
|
|
if (target_hist_data->n_field_var_hists >= SYNTH_FIELDS_MAX) {
|
|
|
|
|
hist_err_event("onmatch: Too many field variables defined: ",
|
|
|
|
|
subsys_name, event_name, field_name);
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:51:59 +08:00
|
|
|
return ERR_PTR(-EINVAL);
|
2018-01-16 10:52:05 +08:00
|
|
|
}
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:51:59 +08:00
|
|
|
|
|
|
|
|
file = event_file(tr, subsys_name, event_name);
|
|
|
|
|
|
|
|
|
|
if (IS_ERR(file)) {
|
2018-01-16 10:52:05 +08:00
|
|
|
hist_err_event("onmatch: Event file not found: ",
|
|
|
|
|
subsys_name, event_name, field_name);
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:51:59 +08:00
|
|
|
ret = PTR_ERR(file);
|
|
|
|
|
return ERR_PTR(ret);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Look for a histogram compatible with target. We'll use the
|
|
|
|
|
* found histogram specification to create a new matching
|
|
|
|
|
* histogram with our variable on it. target_hist_data is not
|
|
|
|
|
* yet a registered histogram so we can't use that.
|
|
|
|
|
*/
|
|
|
|
|
hist_data = find_compatible_hist(target_hist_data, file);
|
2018-01-16 10:52:05 +08:00
|
|
|
if (!hist_data) {
|
|
|
|
|
hist_err_event("onmatch: Matching event histogram not found: ",
|
|
|
|
|
subsys_name, event_name, field_name);
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:51:59 +08:00
|
|
|
return ERR_PTR(-EINVAL);
|
2018-01-16 10:52:05 +08:00
|
|
|
}
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:51:59 +08:00
|
|
|
|
|
|
|
|
/* See if a synthetic field variable has already been created */
|
|
|
|
|
event_var = find_synthetic_field_var(target_hist_data, subsys_name,
|
|
|
|
|
event_name, field_name);
|
|
|
|
|
if (!IS_ERR_OR_NULL(event_var))
|
|
|
|
|
return event_var;
|
|
|
|
|
|
|
|
|
|
var_hist = kzalloc(sizeof(*var_hist), GFP_KERNEL);
|
|
|
|
|
if (!var_hist)
|
|
|
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
|
|
|
|
|
|
cmd = kzalloc(MAX_FILTER_STR_VAL, GFP_KERNEL);
|
|
|
|
|
if (!cmd) {
|
|
|
|
|
kfree(var_hist);
|
|
|
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/* Use the same keys as the compatible histogram */
|
|
|
|
|
strcat(cmd, "keys=");
|
|
|
|
|
|
|
|
|
|
for_each_hist_key_field(i, hist_data) {
|
|
|
|
|
key_field = hist_data->fields[i];
|
|
|
|
|
if (!first)
|
|
|
|
|
strcat(cmd, ",");
|
|
|
|
|
strcat(cmd, key_field->field->name);
|
|
|
|
|
first = false;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/* Create the synthetic field variable specification */
|
|
|
|
|
strcat(cmd, ":synthetic_");
|
|
|
|
|
strcat(cmd, field_name);
|
|
|
|
|
strcat(cmd, "=");
|
|
|
|
|
strcat(cmd, field_name);
|
|
|
|
|
|
|
|
|
|
/* Use the same filter as the compatible histogram */
|
|
|
|
|
saved_filter = find_trigger_filter(hist_data, file);
|
|
|
|
|
if (saved_filter) {
|
|
|
|
|
strcat(cmd, " if ");
|
|
|
|
|
strcat(cmd, saved_filter);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
var_hist->cmd = kstrdup(cmd, GFP_KERNEL);
|
|
|
|
|
if (!var_hist->cmd) {
|
|
|
|
|
kfree(cmd);
|
|
|
|
|
kfree(var_hist);
|
|
|
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/* Save the compatible histogram information */
|
|
|
|
|
var_hist->hist_data = hist_data;
|
|
|
|
|
|
|
|
|
|
/* Create the new histogram with our variable */
|
|
|
|
|
ret = event_hist_trigger_func(&trigger_hist_cmd, file,
|
|
|
|
|
"", "hist", cmd);
|
|
|
|
|
if (ret) {
|
|
|
|
|
kfree(cmd);
|
|
|
|
|
kfree(var_hist->cmd);
|
|
|
|
|
kfree(var_hist);
|
2018-01-16 10:52:05 +08:00
|
|
|
hist_err_event("onmatch: Couldn't create histogram for field: ",
|
|
|
|
|
subsys_name, event_name, field_name);
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:51:59 +08:00
|
|
|
return ERR_PTR(ret);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
kfree(cmd);
|
|
|
|
|
|
|
|
|
|
/* If we can't find the variable, something went wrong */
|
|
|
|
|
event_var = find_synthetic_field_var(target_hist_data, subsys_name,
|
|
|
|
|
event_name, field_name);
|
|
|
|
|
if (IS_ERR_OR_NULL(event_var)) {
|
|
|
|
|
kfree(var_hist->cmd);
|
|
|
|
|
kfree(var_hist);
|
2018-01-16 10:52:05 +08:00
|
|
|
hist_err_event("onmatch: Couldn't find synthetic variable: ",
|
|
|
|
|
subsys_name, event_name, field_name);
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:51:59 +08:00
|
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
n = target_hist_data->n_field_var_hists;
|
|
|
|
|
target_hist_data->field_var_hists[n] = var_hist;
|
|
|
|
|
target_hist_data->n_field_var_hists++;
|
|
|
|
|
|
|
|
|
|
return event_var;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:52:00 +08:00
|
|
|
static struct hist_field *
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:51:59 +08:00
|
|
|
find_target_event_var(struct hist_trigger_data *hist_data,
|
|
|
|
|
char *subsys_name, char *event_name, char *var_name)
|
|
|
|
|
{
|
|
|
|
|
struct trace_event_file *file = hist_data->event_file;
|
|
|
|
|
struct hist_field *hist_field = NULL;
|
|
|
|
|
|
|
|
|
|
if (subsys_name) {
|
|
|
|
|
struct trace_event_call *call;
|
|
|
|
|
|
|
|
|
|
if (!event_name)
|
|
|
|
|
return NULL;
|
|
|
|
|
|
|
|
|
|
call = file->event_call;
|
|
|
|
|
|
|
|
|
|
if (strcmp(subsys_name, call->class->system) != 0)
|
|
|
|
|
return NULL;
|
|
|
|
|
|
|
|
|
|
if (strcmp(event_name, trace_event_name(call)) != 0)
|
|
|
|
|
return NULL;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
hist_field = find_var_field(hist_data, var_name);
|
|
|
|
|
|
|
|
|
|
return hist_field;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static inline void __update_field_vars(struct tracing_map_elt *elt,
|
|
|
|
|
struct ring_buffer_event *rbe,
|
|
|
|
|
void *rec,
|
|
|
|
|
struct field_var **field_vars,
|
|
|
|
|
unsigned int n_field_vars,
|
|
|
|
|
unsigned int field_var_str_start)
|
|
|
|
|
{
|
|
|
|
|
struct hist_elt_data *elt_data = elt->private_data;
|
|
|
|
|
unsigned int i, j, var_idx;
|
|
|
|
|
u64 var_val;
|
|
|
|
|
|
|
|
|
|
for (i = 0, j = field_var_str_start; i < n_field_vars; i++) {
|
|
|
|
|
struct field_var *field_var = field_vars[i];
|
|
|
|
|
struct hist_field *var = field_var->var;
|
|
|
|
|
struct hist_field *val = field_var->val;
|
|
|
|
|
|
|
|
|
|
var_val = val->fn(val, elt, rbe, rec);
|
|
|
|
|
var_idx = var->var.idx;
|
|
|
|
|
|
|
|
|
|
if (val->flags & HIST_FIELD_FL_STRING) {
|
|
|
|
|
char *str = elt_data->field_var_str[j++];
|
|
|
|
|
char *val_str = (char *)(uintptr_t)var_val;
|
|
|
|
|
|
|
|
|
|
strncpy(str, val_str, STR_VAR_LEN_MAX);
|
|
|
|
|
var_val = (u64)(uintptr_t)str;
|
|
|
|
|
}
|
|
|
|
|
tracing_map_set_var(elt, var_idx, var_val);
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void update_field_vars(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct tracing_map_elt *elt,
|
|
|
|
|
struct ring_buffer_event *rbe,
|
|
|
|
|
void *rec)
|
|
|
|
|
{
|
|
|
|
|
__update_field_vars(elt, rbe, rec, hist_data->field_vars,
|
|
|
|
|
hist_data->n_field_vars, 0);
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:52:01 +08:00
|
|
|
static void update_max_vars(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct tracing_map_elt *elt,
|
|
|
|
|
struct ring_buffer_event *rbe,
|
|
|
|
|
void *rec)
|
|
|
|
|
{
|
|
|
|
|
__update_field_vars(elt, rbe, rec, hist_data->max_vars,
|
|
|
|
|
hist_data->n_max_vars, hist_data->n_field_var_str);
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:51:59 +08:00
|
|
|
static struct hist_field *create_var(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct trace_event_file *file,
|
|
|
|
|
char *name, int size, const char *type)
|
|
|
|
|
{
|
|
|
|
|
struct hist_field *var;
|
|
|
|
|
int idx;
|
|
|
|
|
|
|
|
|
|
if (find_var(hist_data, file, name) && !hist_data->remove) {
|
|
|
|
|
var = ERR_PTR(-EINVAL);
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
var = kzalloc(sizeof(struct hist_field), GFP_KERNEL);
|
|
|
|
|
if (!var) {
|
|
|
|
|
var = ERR_PTR(-ENOMEM);
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
idx = tracing_map_add_var(hist_data->map);
|
|
|
|
|
if (idx < 0) {
|
|
|
|
|
kfree(var);
|
|
|
|
|
var = ERR_PTR(-EINVAL);
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
var->flags = HIST_FIELD_FL_VAR;
|
|
|
|
|
var->var.idx = idx;
|
|
|
|
|
var->var.hist_data = var->hist_data = hist_data;
|
|
|
|
|
var->size = size;
|
|
|
|
|
var->var.name = kstrdup(name, GFP_KERNEL);
|
|
|
|
|
var->type = kstrdup(type, GFP_KERNEL);
|
|
|
|
|
if (!var->var.name || !var->type) {
|
|
|
|
|
kfree(var->var.name);
|
|
|
|
|
kfree(var->type);
|
|
|
|
|
kfree(var);
|
|
|
|
|
var = ERR_PTR(-ENOMEM);
|
|
|
|
|
}
|
|
|
|
|
out:
|
|
|
|
|
return var;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static struct field_var *create_field_var(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct trace_event_file *file,
|
|
|
|
|
char *field_name)
|
|
|
|
|
{
|
|
|
|
|
struct hist_field *val = NULL, *var = NULL;
|
|
|
|
|
unsigned long flags = HIST_FIELD_FL_VAR;
|
|
|
|
|
struct field_var *field_var;
|
|
|
|
|
int ret = 0;
|
|
|
|
|
|
|
|
|
|
if (hist_data->n_field_vars >= SYNTH_FIELDS_MAX) {
|
2018-01-16 10:52:05 +08:00
|
|
|
hist_err("Too many field variables defined: ", field_name);
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:51:59 +08:00
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto err;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
val = parse_atom(hist_data, file, field_name, &flags, NULL);
|
|
|
|
|
if (IS_ERR(val)) {
|
2018-01-16 10:52:05 +08:00
|
|
|
hist_err("Couldn't parse field variable: ", field_name);
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:51:59 +08:00
|
|
|
ret = PTR_ERR(val);
|
|
|
|
|
goto err;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
var = create_var(hist_data, file, field_name, val->size, val->type);
|
|
|
|
|
if (IS_ERR(var)) {
|
2018-01-16 10:52:05 +08:00
|
|
|
hist_err("Couldn't create or find variable: ", field_name);
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:51:59 +08:00
|
|
|
kfree(val);
|
|
|
|
|
ret = PTR_ERR(var);
|
|
|
|
|
goto err;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
field_var = kzalloc(sizeof(struct field_var), GFP_KERNEL);
|
|
|
|
|
if (!field_var) {
|
|
|
|
|
kfree(val);
|
|
|
|
|
kfree(var);
|
|
|
|
|
ret = -ENOMEM;
|
|
|
|
|
goto err;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
field_var->var = var;
|
|
|
|
|
field_var->val = val;
|
|
|
|
|
out:
|
|
|
|
|
return field_var;
|
|
|
|
|
err:
|
|
|
|
|
field_var = ERR_PTR(ret);
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/**
|
|
|
|
|
* create_target_field_var - Automatically create a variable for a field
|
|
|
|
|
* @target_hist_data: The target hist trigger
|
|
|
|
|
* @subsys_name: Optional subsystem name
|
|
|
|
|
* @event_name: Optional event name
|
|
|
|
|
* @var_name: The name of the field (and the resulting variable)
|
|
|
|
|
*
|
|
|
|
|
* Hist trigger actions fetch data from variables, not directly from
|
|
|
|
|
* events. However, for convenience, users are allowed to directly
|
|
|
|
|
* specify an event field in an action, which will be automatically
|
|
|
|
|
* converted into a variable on their behalf.
|
|
|
|
|
|
|
|
|
|
* This function creates a field variable with the name var_name on
|
|
|
|
|
* the hist trigger currently being defined on the target event. If
|
|
|
|
|
* subsys_name and event_name are specified, this function simply
|
|
|
|
|
* verifies that they do in fact match the target event subsystem and
|
|
|
|
|
* event name.
|
|
|
|
|
*
|
|
|
|
|
* Return: The variable created for the field.
|
|
|
|
|
*/
|
2018-01-16 10:52:00 +08:00
|
|
|
static struct field_var *
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:51:59 +08:00
|
|
|
create_target_field_var(struct hist_trigger_data *target_hist_data,
|
|
|
|
|
char *subsys_name, char *event_name, char *var_name)
|
|
|
|
|
{
|
|
|
|
|
struct trace_event_file *file = target_hist_data->event_file;
|
|
|
|
|
|
|
|
|
|
if (subsys_name) {
|
|
|
|
|
struct trace_event_call *call;
|
|
|
|
|
|
|
|
|
|
if (!event_name)
|
|
|
|
|
return NULL;
|
|
|
|
|
|
|
|
|
|
call = file->event_call;
|
|
|
|
|
|
|
|
|
|
if (strcmp(subsys_name, call->class->system) != 0)
|
|
|
|
|
return NULL;
|
|
|
|
|
|
|
|
|
|
if (strcmp(event_name, trace_event_name(call)) != 0)
|
|
|
|
|
return NULL;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return create_field_var(target_hist_data, file, var_name);
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:52:01 +08:00
|
|
|
static void onmax_print(struct seq_file *m,
|
|
|
|
|
struct hist_trigger_data *hist_data,
|
|
|
|
|
struct tracing_map_elt *elt,
|
|
|
|
|
struct action_data *data)
|
|
|
|
|
{
|
|
|
|
|
unsigned int i, save_var_idx, max_idx = data->onmax.max_var->var.idx;
|
|
|
|
|
|
|
|
|
|
seq_printf(m, "\n\tmax: %10llu", tracing_map_read_var(elt, max_idx));
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < hist_data->n_max_vars; i++) {
|
|
|
|
|
struct hist_field *save_val = hist_data->max_vars[i]->val;
|
|
|
|
|
struct hist_field *save_var = hist_data->max_vars[i]->var;
|
|
|
|
|
u64 val;
|
|
|
|
|
|
|
|
|
|
save_var_idx = save_var->var.idx;
|
|
|
|
|
|
|
|
|
|
val = tracing_map_read_var(elt, save_var_idx);
|
|
|
|
|
|
|
|
|
|
if (save_val->flags & HIST_FIELD_FL_STRING) {
|
|
|
|
|
seq_printf(m, " %s: %-32s", save_var->var.name,
|
|
|
|
|
(char *)(uintptr_t)(val));
|
|
|
|
|
} else
|
|
|
|
|
seq_printf(m, " %s: %10llu", save_var->var.name, val);
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void onmax_save(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct tracing_map_elt *elt, void *rec,
|
|
|
|
|
struct ring_buffer_event *rbe,
|
|
|
|
|
struct action_data *data, u64 *var_ref_vals)
|
|
|
|
|
{
|
|
|
|
|
unsigned int max_idx = data->onmax.max_var->var.idx;
|
|
|
|
|
unsigned int max_var_ref_idx = data->onmax.max_var_ref_idx;
|
|
|
|
|
|
|
|
|
|
u64 var_val, max_val;
|
|
|
|
|
|
|
|
|
|
var_val = var_ref_vals[max_var_ref_idx];
|
|
|
|
|
max_val = tracing_map_read_var(elt, max_idx);
|
|
|
|
|
|
|
|
|
|
if (var_val <= max_val)
|
|
|
|
|
return;
|
|
|
|
|
|
|
|
|
|
tracing_map_set_var(elt, max_idx, var_val);
|
|
|
|
|
|
|
|
|
|
update_max_vars(hist_data, elt, rbe, rec);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void onmax_destroy(struct action_data *data)
|
|
|
|
|
{
|
|
|
|
|
unsigned int i;
|
|
|
|
|
|
|
|
|
|
destroy_hist_field(data->onmax.max_var, 0);
|
|
|
|
|
destroy_hist_field(data->onmax.var, 0);
|
|
|
|
|
|
|
|
|
|
kfree(data->onmax.var_str);
|
|
|
|
|
kfree(data->onmax.fn_name);
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < data->n_params; i++)
|
|
|
|
|
kfree(data->params[i]);
|
|
|
|
|
|
|
|
|
|
kfree(data);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int onmax_create(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct action_data *data)
|
|
|
|
|
{
|
|
|
|
|
struct trace_event_file *file = hist_data->event_file;
|
|
|
|
|
struct hist_field *var_field, *ref_field, *max_var;
|
|
|
|
|
unsigned int var_ref_idx = hist_data->n_var_refs;
|
|
|
|
|
struct field_var *field_var;
|
|
|
|
|
char *onmax_var_str, *param;
|
|
|
|
|
unsigned long flags;
|
|
|
|
|
unsigned int i;
|
|
|
|
|
int ret = 0;
|
|
|
|
|
|
|
|
|
|
onmax_var_str = data->onmax.var_str;
|
2018-01-16 10:52:05 +08:00
|
|
|
if (onmax_var_str[0] != '$') {
|
|
|
|
|
hist_err("onmax: For onmax(x), x must be a variable: ", onmax_var_str);
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:52:01 +08:00
|
|
|
return -EINVAL;
|
2018-01-16 10:52:05 +08:00
|
|
|
}
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:52:01 +08:00
|
|
|
onmax_var_str++;
|
|
|
|
|
|
|
|
|
|
var_field = find_target_event_var(hist_data, NULL, NULL, onmax_var_str);
|
2018-01-16 10:52:05 +08:00
|
|
|
if (!var_field) {
|
|
|
|
|
hist_err("onmax: Couldn't find onmax variable: ", onmax_var_str);
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:52:01 +08:00
|
|
|
return -EINVAL;
|
2018-01-16 10:52:05 +08:00
|
|
|
}
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:52:01 +08:00
|
|
|
|
|
|
|
|
flags = HIST_FIELD_FL_VAR_REF;
|
|
|
|
|
ref_field = create_hist_field(hist_data, NULL, flags, NULL);
|
|
|
|
|
if (!ref_field)
|
|
|
|
|
return -ENOMEM;
|
|
|
|
|
|
|
|
|
|
if (init_var_ref(ref_field, var_field, NULL, NULL)) {
|
|
|
|
|
destroy_hist_field(ref_field, 0);
|
|
|
|
|
ret = -ENOMEM;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
hist_data->var_refs[hist_data->n_var_refs] = ref_field;
|
|
|
|
|
ref_field->var_ref_idx = hist_data->n_var_refs++;
|
|
|
|
|
data->onmax.var = ref_field;
|
|
|
|
|
|
|
|
|
|
data->fn = onmax_save;
|
|
|
|
|
data->onmax.max_var_ref_idx = var_ref_idx;
|
|
|
|
|
max_var = create_var(hist_data, file, "max", sizeof(u64), "u64");
|
|
|
|
|
if (IS_ERR(max_var)) {
|
2018-01-16 10:52:05 +08:00
|
|
|
hist_err("onmax: Couldn't create onmax variable: ", "max");
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:52:01 +08:00
|
|
|
ret = PTR_ERR(max_var);
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
data->onmax.max_var = max_var;
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < data->n_params; i++) {
|
|
|
|
|
param = kstrdup(data->params[i], GFP_KERNEL);
|
|
|
|
|
if (!param) {
|
|
|
|
|
ret = -ENOMEM;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
field_var = create_target_field_var(hist_data, NULL, NULL, param);
|
|
|
|
|
if (IS_ERR(field_var)) {
|
2018-01-16 10:52:05 +08:00
|
|
|
hist_err("onmax: Couldn't create field variable: ", param);
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:52:01 +08:00
|
|
|
ret = PTR_ERR(field_var);
|
|
|
|
|
kfree(param);
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
hist_data->max_vars[hist_data->n_max_vars++] = field_var;
|
|
|
|
|
if (field_var->val->flags & HIST_FIELD_FL_STRING)
|
|
|
|
|
hist_data->n_max_var_str++;
|
|
|
|
|
|
|
|
|
|
kfree(param);
|
|
|
|
|
}
|
|
|
|
|
out:
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int parse_action_params(char *params, struct action_data *data)
|
|
|
|
|
{
|
|
|
|
|
char *param, *saved_param;
|
|
|
|
|
int ret = 0;
|
|
|
|
|
|
|
|
|
|
while (params) {
|
|
|
|
|
if (data->n_params >= SYNTH_FIELDS_MAX)
|
|
|
|
|
goto out;
|
|
|
|
|
|
|
|
|
|
param = strsep(¶ms, ",");
|
|
|
|
|
if (!param) {
|
|
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
param = strstrip(param);
|
|
|
|
|
if (strlen(param) < 2) {
|
2018-01-16 10:52:05 +08:00
|
|
|
hist_err("Invalid action param: ", param);
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:52:01 +08:00
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
saved_param = kstrdup(param, GFP_KERNEL);
|
|
|
|
|
if (!saved_param) {
|
|
|
|
|
ret = -ENOMEM;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
data->params[data->n_params++] = saved_param;
|
|
|
|
|
}
|
|
|
|
|
out:
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static struct action_data *onmax_parse(char *str)
|
|
|
|
|
{
|
|
|
|
|
char *onmax_fn_name, *onmax_var_str;
|
|
|
|
|
struct action_data *data;
|
|
|
|
|
int ret = -EINVAL;
|
|
|
|
|
|
|
|
|
|
data = kzalloc(sizeof(*data), GFP_KERNEL);
|
|
|
|
|
if (!data)
|
|
|
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
|
|
|
|
|
|
onmax_var_str = strsep(&str, ")");
|
|
|
|
|
if (!onmax_var_str || !str) {
|
|
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
data->onmax.var_str = kstrdup(onmax_var_str, GFP_KERNEL);
|
|
|
|
|
if (!data->onmax.var_str) {
|
|
|
|
|
ret = -ENOMEM;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
strsep(&str, ".");
|
|
|
|
|
if (!str)
|
|
|
|
|
goto free;
|
|
|
|
|
|
|
|
|
|
onmax_fn_name = strsep(&str, "(");
|
|
|
|
|
if (!onmax_fn_name || !str)
|
|
|
|
|
goto free;
|
|
|
|
|
|
|
|
|
|
if (strncmp(onmax_fn_name, "save", strlen("save")) == 0) {
|
|
|
|
|
char *params = strsep(&str, ")");
|
|
|
|
|
|
|
|
|
|
if (!params) {
|
|
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
ret = parse_action_params(params, data);
|
|
|
|
|
if (ret)
|
|
|
|
|
goto free;
|
|
|
|
|
} else
|
|
|
|
|
goto free;
|
|
|
|
|
|
|
|
|
|
data->onmax.fn_name = kstrdup(onmax_fn_name, GFP_KERNEL);
|
|
|
|
|
if (!data->onmax.fn_name) {
|
|
|
|
|
ret = -ENOMEM;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
|
|
|
|
out:
|
|
|
|
|
return data;
|
|
|
|
|
free:
|
|
|
|
|
onmax_destroy(data);
|
|
|
|
|
data = ERR_PTR(ret);
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:52:00 +08:00
|
|
|
static void onmatch_destroy(struct action_data *data)
|
|
|
|
|
{
|
|
|
|
|
unsigned int i;
|
|
|
|
|
|
|
|
|
|
mutex_lock(&synth_event_mutex);
|
|
|
|
|
|
|
|
|
|
kfree(data->onmatch.match_event);
|
|
|
|
|
kfree(data->onmatch.match_event_system);
|
|
|
|
|
kfree(data->onmatch.synth_event_name);
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < data->n_params; i++)
|
|
|
|
|
kfree(data->params[i]);
|
|
|
|
|
|
|
|
|
|
if (data->onmatch.synth_event)
|
|
|
|
|
data->onmatch.synth_event->ref--;
|
|
|
|
|
|
|
|
|
|
kfree(data);
|
|
|
|
|
|
|
|
|
|
mutex_unlock(&synth_event_mutex);
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:51:59 +08:00
|
|
|
static void destroy_field_var(struct field_var *field_var)
|
|
|
|
|
{
|
|
|
|
|
if (!field_var)
|
|
|
|
|
return;
|
|
|
|
|
|
|
|
|
|
destroy_hist_field(field_var->var, 0);
|
|
|
|
|
destroy_hist_field(field_var->val, 0);
|
|
|
|
|
|
|
|
|
|
kfree(field_var);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void destroy_field_vars(struct hist_trigger_data *hist_data)
|
|
|
|
|
{
|
|
|
|
|
unsigned int i;
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < hist_data->n_field_vars; i++)
|
|
|
|
|
destroy_field_var(hist_data->field_vars[i]);
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:52:00 +08:00
|
|
|
static void save_field_var(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct field_var *field_var)
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:51:59 +08:00
|
|
|
{
|
|
|
|
|
hist_data->field_vars[hist_data->n_field_vars++] = field_var;
|
|
|
|
|
|
|
|
|
|
if (field_var->val->flags & HIST_FIELD_FL_STRING)
|
|
|
|
|
hist_data->n_field_var_str++;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:52:00 +08:00
|
|
|
|
|
|
|
|
static void destroy_synth_var_refs(struct hist_trigger_data *hist_data)
|
|
|
|
|
{
|
|
|
|
|
unsigned int i;
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < hist_data->n_synth_var_refs; i++)
|
|
|
|
|
destroy_hist_field(hist_data->synth_var_refs[i], 0);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void save_synth_var_ref(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct hist_field *var_ref)
|
|
|
|
|
{
|
|
|
|
|
hist_data->synth_var_refs[hist_data->n_synth_var_refs++] = var_ref;
|
|
|
|
|
|
|
|
|
|
hist_data->var_refs[hist_data->n_var_refs] = var_ref;
|
|
|
|
|
var_ref->var_ref_idx = hist_data->n_var_refs++;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int check_synth_field(struct synth_event *event,
|
|
|
|
|
struct hist_field *hist_field,
|
|
|
|
|
unsigned int field_pos)
|
|
|
|
|
{
|
|
|
|
|
struct synth_field *field;
|
|
|
|
|
|
|
|
|
|
if (field_pos >= event->n_fields)
|
|
|
|
|
return -EINVAL;
|
|
|
|
|
|
|
|
|
|
field = event->fields[field_pos];
|
|
|
|
|
|
|
|
|
|
if (strcmp(field->type, hist_field->type) != 0)
|
|
|
|
|
return -EINVAL;
|
|
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static struct hist_field *
|
|
|
|
|
onmatch_find_var(struct hist_trigger_data *hist_data, struct action_data *data,
|
|
|
|
|
char *system, char *event, char *var)
|
|
|
|
|
{
|
|
|
|
|
struct hist_field *hist_field;
|
|
|
|
|
|
|
|
|
|
var++; /* skip '$' */
|
|
|
|
|
|
|
|
|
|
hist_field = find_target_event_var(hist_data, system, event, var);
|
|
|
|
|
if (!hist_field) {
|
|
|
|
|
if (!system) {
|
|
|
|
|
system = data->onmatch.match_event_system;
|
|
|
|
|
event = data->onmatch.match_event;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
hist_field = find_event_var(hist_data, system, event, var);
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:52:05 +08:00
|
|
|
if (!hist_field)
|
|
|
|
|
hist_err_event("onmatch: Couldn't find onmatch param: $", system, event, var);
|
|
|
|
|
|
2018-01-16 10:52:00 +08:00
|
|
|
return hist_field;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static struct hist_field *
|
|
|
|
|
onmatch_create_field_var(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct action_data *data, char *system,
|
|
|
|
|
char *event, char *var)
|
|
|
|
|
{
|
|
|
|
|
struct hist_field *hist_field = NULL;
|
|
|
|
|
struct field_var *field_var;
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* First try to create a field var on the target event (the
|
|
|
|
|
* currently being defined). This will create a variable for
|
|
|
|
|
* unqualified fields on the target event, or if qualified,
|
|
|
|
|
* target fields that have qualified names matching the target.
|
|
|
|
|
*/
|
|
|
|
|
field_var = create_target_field_var(hist_data, system, event, var);
|
|
|
|
|
|
|
|
|
|
if (field_var && !IS_ERR(field_var)) {
|
|
|
|
|
save_field_var(hist_data, field_var);
|
|
|
|
|
hist_field = field_var->var;
|
|
|
|
|
} else {
|
|
|
|
|
field_var = NULL;
|
|
|
|
|
/*
|
|
|
|
|
* If no explicit system.event is specfied, default to
|
|
|
|
|
* looking for fields on the onmatch(system.event.xxx)
|
|
|
|
|
* event.
|
|
|
|
|
*/
|
|
|
|
|
if (!system) {
|
|
|
|
|
system = data->onmatch.match_event_system;
|
|
|
|
|
event = data->onmatch.match_event;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* At this point, we're looking at a field on another
|
|
|
|
|
* event. Because we can't modify a hist trigger on
|
|
|
|
|
* another event to add a variable for a field, we need
|
|
|
|
|
* to create a new trigger on that event and create the
|
|
|
|
|
* variable at the same time.
|
|
|
|
|
*/
|
|
|
|
|
hist_field = create_field_var_hist(hist_data, system, event, var);
|
|
|
|
|
if (IS_ERR(hist_field))
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
|
|
|
|
out:
|
|
|
|
|
return hist_field;
|
|
|
|
|
free:
|
|
|
|
|
destroy_field_var(field_var);
|
|
|
|
|
hist_field = NULL;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int onmatch_create(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct trace_event_file *file,
|
|
|
|
|
struct action_data *data)
|
|
|
|
|
{
|
|
|
|
|
char *event_name, *param, *system = NULL;
|
|
|
|
|
struct hist_field *hist_field, *var_ref;
|
|
|
|
|
unsigned int i, var_ref_idx;
|
|
|
|
|
unsigned int field_pos = 0;
|
|
|
|
|
struct synth_event *event;
|
|
|
|
|
int ret = 0;
|
|
|
|
|
|
|
|
|
|
mutex_lock(&synth_event_mutex);
|
|
|
|
|
event = find_synth_event(data->onmatch.synth_event_name);
|
|
|
|
|
if (!event) {
|
2018-01-16 10:52:05 +08:00
|
|
|
hist_err("onmatch: Couldn't find synthetic event: ", data->onmatch.synth_event_name);
|
2018-01-16 10:52:00 +08:00
|
|
|
mutex_unlock(&synth_event_mutex);
|
|
|
|
|
return -EINVAL;
|
|
|
|
|
}
|
|
|
|
|
event->ref++;
|
|
|
|
|
mutex_unlock(&synth_event_mutex);
|
|
|
|
|
|
|
|
|
|
var_ref_idx = hist_data->n_var_refs;
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < data->n_params; i++) {
|
|
|
|
|
char *p;
|
|
|
|
|
|
|
|
|
|
p = param = kstrdup(data->params[i], GFP_KERNEL);
|
|
|
|
|
if (!param) {
|
|
|
|
|
ret = -ENOMEM;
|
|
|
|
|
goto err;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
system = strsep(¶m, ".");
|
|
|
|
|
if (!param) {
|
|
|
|
|
param = (char *)system;
|
|
|
|
|
system = event_name = NULL;
|
|
|
|
|
} else {
|
|
|
|
|
event_name = strsep(¶m, ".");
|
|
|
|
|
if (!param) {
|
|
|
|
|
kfree(p);
|
|
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto err;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if (param[0] == '$')
|
|
|
|
|
hist_field = onmatch_find_var(hist_data, data, system,
|
|
|
|
|
event_name, param);
|
|
|
|
|
else
|
|
|
|
|
hist_field = onmatch_create_field_var(hist_data, data,
|
|
|
|
|
system,
|
|
|
|
|
event_name,
|
|
|
|
|
param);
|
|
|
|
|
|
|
|
|
|
if (!hist_field) {
|
|
|
|
|
kfree(p);
|
|
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto err;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if (check_synth_field(event, hist_field, field_pos) == 0) {
|
|
|
|
|
var_ref = create_var_ref(hist_field, system, event_name);
|
|
|
|
|
if (!var_ref) {
|
|
|
|
|
kfree(p);
|
|
|
|
|
ret = -ENOMEM;
|
|
|
|
|
goto err;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
save_synth_var_ref(hist_data, var_ref);
|
|
|
|
|
field_pos++;
|
|
|
|
|
kfree(p);
|
|
|
|
|
continue;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:52:05 +08:00
|
|
|
hist_err_event("onmatch: Param type doesn't match synthetic event field type: ",
|
|
|
|
|
system, event_name, param);
|
2018-01-16 10:52:00 +08:00
|
|
|
kfree(p);
|
|
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto err;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if (field_pos != event->n_fields) {
|
2018-01-16 10:52:05 +08:00
|
|
|
hist_err("onmatch: Param count doesn't match synthetic event field count: ", event->name);
|
2018-01-16 10:52:00 +08:00
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto err;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
data->fn = action_trace;
|
|
|
|
|
data->onmatch.synth_event = event;
|
|
|
|
|
data->onmatch.var_ref_idx = var_ref_idx;
|
|
|
|
|
out:
|
|
|
|
|
return ret;
|
|
|
|
|
err:
|
|
|
|
|
mutex_lock(&synth_event_mutex);
|
|
|
|
|
event->ref--;
|
|
|
|
|
mutex_unlock(&synth_event_mutex);
|
|
|
|
|
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static struct action_data *onmatch_parse(struct trace_array *tr, char *str)
|
|
|
|
|
{
|
|
|
|
|
char *match_event, *match_event_system;
|
|
|
|
|
char *synth_event_name, *params;
|
|
|
|
|
struct action_data *data;
|
|
|
|
|
int ret = -EINVAL;
|
|
|
|
|
|
|
|
|
|
data = kzalloc(sizeof(*data), GFP_KERNEL);
|
|
|
|
|
if (!data)
|
|
|
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
|
|
|
|
|
|
match_event = strsep(&str, ")");
|
2018-01-16 10:52:05 +08:00
|
|
|
if (!match_event || !str) {
|
|
|
|
|
hist_err("onmatch: Missing closing paren: ", match_event);
|
2018-01-16 10:52:00 +08:00
|
|
|
goto free;
|
2018-01-16 10:52:05 +08:00
|
|
|
}
|
2018-01-16 10:52:00 +08:00
|
|
|
|
|
|
|
|
match_event_system = strsep(&match_event, ".");
|
2018-01-16 10:52:05 +08:00
|
|
|
if (!match_event) {
|
|
|
|
|
hist_err("onmatch: Missing subsystem for match event: ", match_event_system);
|
2018-01-16 10:52:00 +08:00
|
|
|
goto free;
|
2018-01-16 10:52:05 +08:00
|
|
|
}
|
2018-01-16 10:52:00 +08:00
|
|
|
|
2018-01-16 10:52:05 +08:00
|
|
|
if (IS_ERR(event_file(tr, match_event_system, match_event))) {
|
|
|
|
|
hist_err_event("onmatch: Invalid subsystem or event name: ",
|
|
|
|
|
match_event_system, match_event, NULL);
|
2018-01-16 10:52:00 +08:00
|
|
|
goto free;
|
2018-01-16 10:52:05 +08:00
|
|
|
}
|
2018-01-16 10:52:00 +08:00
|
|
|
|
|
|
|
|
data->onmatch.match_event = kstrdup(match_event, GFP_KERNEL);
|
|
|
|
|
if (!data->onmatch.match_event) {
|
|
|
|
|
ret = -ENOMEM;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
data->onmatch.match_event_system = kstrdup(match_event_system, GFP_KERNEL);
|
|
|
|
|
if (!data->onmatch.match_event_system) {
|
|
|
|
|
ret = -ENOMEM;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
strsep(&str, ".");
|
2018-01-16 10:52:05 +08:00
|
|
|
if (!str) {
|
|
|
|
|
hist_err("onmatch: Missing . after onmatch(): ", str);
|
2018-01-16 10:52:00 +08:00
|
|
|
goto free;
|
2018-01-16 10:52:05 +08:00
|
|
|
}
|
2018-01-16 10:52:00 +08:00
|
|
|
|
|
|
|
|
synth_event_name = strsep(&str, "(");
|
2018-01-16 10:52:05 +08:00
|
|
|
if (!synth_event_name || !str) {
|
|
|
|
|
hist_err("onmatch: Missing opening paramlist paren: ", synth_event_name);
|
2018-01-16 10:52:00 +08:00
|
|
|
goto free;
|
2018-01-16 10:52:05 +08:00
|
|
|
}
|
2018-01-16 10:52:00 +08:00
|
|
|
|
|
|
|
|
data->onmatch.synth_event_name = kstrdup(synth_event_name, GFP_KERNEL);
|
|
|
|
|
if (!data->onmatch.synth_event_name) {
|
|
|
|
|
ret = -ENOMEM;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
params = strsep(&str, ")");
|
2018-01-16 10:52:05 +08:00
|
|
|
if (!params || !str || (str && strlen(str))) {
|
|
|
|
|
hist_err("onmatch: Missing closing paramlist paren: ", params);
|
2018-01-16 10:52:00 +08:00
|
|
|
goto free;
|
2018-01-16 10:52:05 +08:00
|
|
|
}
|
2018-01-16 10:52:00 +08:00
|
|
|
|
|
|
|
|
ret = parse_action_params(params, data);
|
|
|
|
|
if (ret)
|
|
|
|
|
goto free;
|
|
|
|
|
out:
|
|
|
|
|
return data;
|
|
|
|
|
free:
|
|
|
|
|
onmatch_destroy(data);
|
|
|
|
|
data = ERR_PTR(ret);
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
static int create_hitcount_val(struct hist_trigger_data *hist_data)
|
|
|
|
|
{
|
|
|
|
|
hist_data->fields[HITCOUNT_IDX] =
|
2018-01-16 10:51:49 +08:00
|
|
|
create_hist_field(hist_data, NULL, HIST_FIELD_FL_HITCOUNT, NULL);
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
if (!hist_data->fields[HITCOUNT_IDX])
|
|
|
|
|
return -ENOMEM;
|
|
|
|
|
|
|
|
|
|
hist_data->n_vals++;
|
2018-01-16 10:51:49 +08:00
|
|
|
hist_data->n_fields++;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
|
|
|
|
|
if (WARN_ON(hist_data->n_vals > TRACING_MAP_VALS_MAX))
|
|
|
|
|
return -EINVAL;
|
|
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:51:49 +08:00
|
|
|
static int __create_val_field(struct hist_trigger_data *hist_data,
|
|
|
|
|
unsigned int val_idx,
|
|
|
|
|
struct trace_event_file *file,
|
|
|
|
|
char *var_name, char *field_str,
|
|
|
|
|
unsigned long flags)
|
2016-03-04 02:54:43 +08:00
|
|
|
{
|
2018-01-16 10:51:52 +08:00
|
|
|
struct hist_field *hist_field;
|
2016-03-04 02:54:43 +08:00
|
|
|
int ret = 0;
|
|
|
|
|
|
2018-01-16 10:51:52 +08:00
|
|
|
hist_field = parse_expr(hist_data, file, field_str, flags, var_name, 0);
|
|
|
|
|
if (IS_ERR(hist_field)) {
|
|
|
|
|
ret = PTR_ERR(hist_field);
|
2016-03-04 02:54:43 +08:00
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:51:52 +08:00
|
|
|
hist_data->fields[val_idx] = hist_field;
|
|
|
|
|
|
2016-03-04 02:54:43 +08:00
|
|
|
++hist_data->n_vals;
|
2018-01-16 10:51:49 +08:00
|
|
|
++hist_data->n_fields;
|
2016-03-04 02:54:43 +08:00
|
|
|
|
2018-01-16 10:51:49 +08:00
|
|
|
if (WARN_ON(hist_data->n_vals > TRACING_MAP_VALS_MAX + TRACING_MAP_VARS_MAX))
|
2016-03-04 02:54:43 +08:00
|
|
|
ret = -EINVAL;
|
|
|
|
|
out:
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:51:49 +08:00
|
|
|
static int create_val_field(struct hist_trigger_data *hist_data,
|
|
|
|
|
unsigned int val_idx,
|
|
|
|
|
struct trace_event_file *file,
|
|
|
|
|
char *field_str)
|
|
|
|
|
{
|
|
|
|
|
if (WARN_ON(val_idx >= TRACING_MAP_VALS_MAX))
|
|
|
|
|
return -EINVAL;
|
|
|
|
|
|
|
|
|
|
return __create_val_field(hist_data, val_idx, file, NULL, field_str, 0);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int create_var_field(struct hist_trigger_data *hist_data,
|
|
|
|
|
unsigned int val_idx,
|
|
|
|
|
struct trace_event_file *file,
|
|
|
|
|
char *var_name, char *expr_str)
|
|
|
|
|
{
|
|
|
|
|
unsigned long flags = 0;
|
|
|
|
|
|
|
|
|
|
if (WARN_ON(val_idx >= TRACING_MAP_VALS_MAX + TRACING_MAP_VARS_MAX))
|
|
|
|
|
return -EINVAL;
|
2018-01-16 10:52:05 +08:00
|
|
|
|
2018-01-16 10:51:49 +08:00
|
|
|
if (find_var(hist_data, file, var_name) && !hist_data->remove) {
|
2018-01-16 10:52:05 +08:00
|
|
|
hist_err("Variable already defined: ", var_name);
|
2018-01-16 10:51:49 +08:00
|
|
|
return -EINVAL;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
flags |= HIST_FIELD_FL_VAR;
|
|
|
|
|
hist_data->n_vars++;
|
|
|
|
|
if (WARN_ON(hist_data->n_vars > TRACING_MAP_VARS_MAX))
|
|
|
|
|
return -EINVAL;
|
|
|
|
|
|
|
|
|
|
return __create_val_field(hist_data, val_idx, file, var_name, expr_str, flags);
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
static int create_val_fields(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct trace_event_file *file)
|
|
|
|
|
{
|
2016-03-04 02:54:43 +08:00
|
|
|
char *fields_str, *field_str;
|
2018-01-16 10:51:49 +08:00
|
|
|
unsigned int i, j = 1;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
int ret;
|
|
|
|
|
|
|
|
|
|
ret = create_hitcount_val(hist_data);
|
2016-03-04 02:54:43 +08:00
|
|
|
if (ret)
|
|
|
|
|
goto out;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
|
2016-03-04 02:54:43 +08:00
|
|
|
fields_str = hist_data->attrs->vals_str;
|
|
|
|
|
if (!fields_str)
|
|
|
|
|
goto out;
|
|
|
|
|
|
|
|
|
|
strsep(&fields_str, "=");
|
|
|
|
|
if (!fields_str)
|
|
|
|
|
goto out;
|
|
|
|
|
|
|
|
|
|
for (i = 0, j = 1; i < TRACING_MAP_VALS_MAX &&
|
|
|
|
|
j < TRACING_MAP_VALS_MAX; i++) {
|
|
|
|
|
field_str = strsep(&fields_str, ",");
|
|
|
|
|
if (!field_str)
|
|
|
|
|
break;
|
2018-01-16 10:51:49 +08:00
|
|
|
|
2016-03-04 02:54:43 +08:00
|
|
|
if (strcmp(field_str, "hitcount") == 0)
|
|
|
|
|
continue;
|
2018-01-16 10:51:49 +08:00
|
|
|
|
2016-03-04 02:54:43 +08:00
|
|
|
ret = create_val_field(hist_data, j++, file, field_str);
|
|
|
|
|
if (ret)
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
2018-01-16 10:51:49 +08:00
|
|
|
|
2016-03-04 02:54:43 +08:00
|
|
|
if (fields_str && (strcmp(fields_str, "hitcount") != 0))
|
|
|
|
|
ret = -EINVAL;
|
|
|
|
|
out:
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int create_key_field(struct hist_trigger_data *hist_data,
|
|
|
|
|
unsigned int key_idx,
|
2016-03-04 02:54:44 +08:00
|
|
|
unsigned int key_offset,
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
struct trace_event_file *file,
|
|
|
|
|
char *field_str)
|
|
|
|
|
{
|
2018-01-16 10:51:49 +08:00
|
|
|
struct hist_field *hist_field = NULL;
|
2018-01-16 10:51:52 +08:00
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
unsigned long flags = 0;
|
|
|
|
|
unsigned int key_size;
|
|
|
|
|
int ret = 0;
|
|
|
|
|
|
2018-01-16 10:51:49 +08:00
|
|
|
if (WARN_ON(key_idx >= HIST_FIELDS_MAX))
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
return -EINVAL;
|
|
|
|
|
|
|
|
|
|
flags |= HIST_FIELD_FL_KEY;
|
|
|
|
|
|
2016-03-04 02:54:52 +08:00
|
|
|
if (strcmp(field_str, "stacktrace") == 0) {
|
|
|
|
|
flags |= HIST_FIELD_FL_STACKTRACE;
|
|
|
|
|
key_size = sizeof(unsigned long) * HIST_STACKTRACE_DEPTH;
|
2018-01-16 10:51:49 +08:00
|
|
|
hist_field = create_hist_field(hist_data, NULL, flags, NULL);
|
2016-03-04 02:54:52 +08:00
|
|
|
} else {
|
2018-01-16 10:51:52 +08:00
|
|
|
hist_field = parse_expr(hist_data, file, field_str, flags,
|
|
|
|
|
NULL, 0);
|
|
|
|
|
if (IS_ERR(hist_field)) {
|
|
|
|
|
ret = PTR_ERR(hist_field);
|
|
|
|
|
goto out;
|
2016-03-04 02:54:52 +08:00
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:51:56 +08:00
|
|
|
if (hist_field->flags & HIST_FIELD_FL_VAR_REF) {
|
2018-01-16 10:52:05 +08:00
|
|
|
hist_err("Using variable references as keys not supported: ", field_str);
|
2018-01-16 10:51:56 +08:00
|
|
|
destroy_hist_field(hist_field, 0);
|
|
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:51:52 +08:00
|
|
|
key_size = hist_field->size;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:51:52 +08:00
|
|
|
hist_data->fields[key_idx] = hist_field;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
|
|
|
|
|
key_size = ALIGN(key_size, sizeof(u64));
|
|
|
|
|
hist_data->fields[key_idx]->size = key_size;
|
2016-03-04 02:54:44 +08:00
|
|
|
hist_data->fields[key_idx]->offset = key_offset;
|
2018-01-16 10:51:52 +08:00
|
|
|
|
2016-03-04 02:54:44 +08:00
|
|
|
hist_data->key_size += key_size;
|
2018-01-16 10:51:52 +08:00
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
if (hist_data->key_size > HIST_KEY_SIZE_MAX) {
|
|
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
hist_data->n_keys++;
|
2018-01-16 10:51:49 +08:00
|
|
|
hist_data->n_fields++;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
|
|
|
|
|
if (WARN_ON(hist_data->n_keys > TRACING_MAP_KEYS_MAX))
|
|
|
|
|
return -EINVAL;
|
|
|
|
|
|
|
|
|
|
ret = key_size;
|
|
|
|
|
out:
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int create_key_fields(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct trace_event_file *file)
|
|
|
|
|
{
|
2016-03-04 02:54:44 +08:00
|
|
|
unsigned int i, key_offset = 0, n_vals = hist_data->n_vals;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
char *fields_str, *field_str;
|
|
|
|
|
int ret = -EINVAL;
|
|
|
|
|
|
|
|
|
|
fields_str = hist_data->attrs->keys_str;
|
|
|
|
|
if (!fields_str)
|
|
|
|
|
goto out;
|
|
|
|
|
|
|
|
|
|
strsep(&fields_str, "=");
|
|
|
|
|
if (!fields_str)
|
|
|
|
|
goto out;
|
|
|
|
|
|
2016-03-04 02:54:44 +08:00
|
|
|
for (i = n_vals; i < n_vals + TRACING_MAP_KEYS_MAX; i++) {
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
field_str = strsep(&fields_str, ",");
|
|
|
|
|
if (!field_str)
|
|
|
|
|
break;
|
2016-03-04 02:54:44 +08:00
|
|
|
ret = create_key_field(hist_data, i, key_offset,
|
|
|
|
|
file, field_str);
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
if (ret < 0)
|
|
|
|
|
goto out;
|
2016-03-04 02:54:44 +08:00
|
|
|
key_offset += ret;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
}
|
|
|
|
|
if (fields_str) {
|
|
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
ret = 0;
|
|
|
|
|
out:
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:51:49 +08:00
|
|
|
static int create_var_fields(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct trace_event_file *file)
|
|
|
|
|
{
|
|
|
|
|
unsigned int i, j = hist_data->n_vals;
|
|
|
|
|
int ret = 0;
|
|
|
|
|
|
|
|
|
|
unsigned int n_vars = hist_data->attrs->var_defs.n_vars;
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < n_vars; i++) {
|
|
|
|
|
char *var_name = hist_data->attrs->var_defs.name[i];
|
|
|
|
|
char *expr = hist_data->attrs->var_defs.expr[i];
|
|
|
|
|
|
|
|
|
|
ret = create_var_field(hist_data, j++, file, var_name, expr);
|
|
|
|
|
if (ret)
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
out:
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void free_var_defs(struct hist_trigger_data *hist_data)
|
|
|
|
|
{
|
|
|
|
|
unsigned int i;
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < hist_data->attrs->var_defs.n_vars; i++) {
|
|
|
|
|
kfree(hist_data->attrs->var_defs.name[i]);
|
|
|
|
|
kfree(hist_data->attrs->var_defs.expr[i]);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
hist_data->attrs->var_defs.n_vars = 0;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int parse_var_defs(struct hist_trigger_data *hist_data)
|
|
|
|
|
{
|
|
|
|
|
char *s, *str, *var_name, *field_str;
|
|
|
|
|
unsigned int i, j, n_vars = 0;
|
|
|
|
|
int ret = 0;
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < hist_data->attrs->n_assignments; i++) {
|
|
|
|
|
str = hist_data->attrs->assignment_str[i];
|
|
|
|
|
for (j = 0; j < TRACING_MAP_VARS_MAX; j++) {
|
|
|
|
|
field_str = strsep(&str, ",");
|
|
|
|
|
if (!field_str)
|
|
|
|
|
break;
|
|
|
|
|
|
|
|
|
|
var_name = strsep(&field_str, "=");
|
|
|
|
|
if (!var_name || !field_str) {
|
2018-01-16 10:52:05 +08:00
|
|
|
hist_err("Malformed assignment: ", var_name);
|
2018-01-16 10:51:49 +08:00
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if (n_vars == TRACING_MAP_VARS_MAX) {
|
2018-01-16 10:52:05 +08:00
|
|
|
hist_err("Too many variables defined: ", var_name);
|
2018-01-16 10:51:49 +08:00
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
s = kstrdup(var_name, GFP_KERNEL);
|
|
|
|
|
if (!s) {
|
|
|
|
|
ret = -ENOMEM;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
|
|
|
|
hist_data->attrs->var_defs.name[n_vars] = s;
|
|
|
|
|
|
|
|
|
|
s = kstrdup(field_str, GFP_KERNEL);
|
|
|
|
|
if (!s) {
|
|
|
|
|
kfree(hist_data->attrs->var_defs.name[n_vars]);
|
|
|
|
|
ret = -ENOMEM;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
|
|
|
|
hist_data->attrs->var_defs.expr[n_vars++] = s;
|
|
|
|
|
|
|
|
|
|
hist_data->attrs->var_defs.n_vars = n_vars;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
|
free:
|
|
|
|
|
free_var_defs(hist_data);
|
|
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
static int create_hist_fields(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct trace_event_file *file)
|
|
|
|
|
{
|
|
|
|
|
int ret;
|
|
|
|
|
|
2018-01-16 10:51:49 +08:00
|
|
|
ret = parse_var_defs(hist_data);
|
|
|
|
|
if (ret)
|
|
|
|
|
goto out;
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
ret = create_val_fields(hist_data, file);
|
|
|
|
|
if (ret)
|
|
|
|
|
goto out;
|
|
|
|
|
|
2018-01-16 10:51:49 +08:00
|
|
|
ret = create_var_fields(hist_data, file);
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
if (ret)
|
|
|
|
|
goto out;
|
|
|
|
|
|
2018-01-16 10:51:49 +08:00
|
|
|
ret = create_key_fields(hist_data, file);
|
|
|
|
|
if (ret)
|
|
|
|
|
goto out;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
out:
|
2018-01-16 10:51:49 +08:00
|
|
|
free_var_defs(hist_data);
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
2016-03-04 02:54:45 +08:00
|
|
|
static int is_descending(const char *str)
|
|
|
|
|
{
|
|
|
|
|
if (!str)
|
|
|
|
|
return 0;
|
|
|
|
|
|
|
|
|
|
if (strcmp(str, "descending") == 0)
|
|
|
|
|
return 1;
|
|
|
|
|
|
|
|
|
|
if (strcmp(str, "ascending") == 0)
|
|
|
|
|
return 0;
|
|
|
|
|
|
|
|
|
|
return -EINVAL;
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
static int create_sort_keys(struct hist_trigger_data *hist_data)
|
|
|
|
|
{
|
2016-03-04 02:54:45 +08:00
|
|
|
char *fields_str = hist_data->attrs->sort_key_str;
|
|
|
|
|
struct tracing_map_sort_key *sort_key;
|
|
|
|
|
int descending, ret = 0;
|
2018-01-16 10:51:49 +08:00
|
|
|
unsigned int i, j, k;
|
2016-03-04 02:54:45 +08:00
|
|
|
|
|
|
|
|
hist_data->n_sort_keys = 1; /* we always have at least one, hitcount */
|
|
|
|
|
|
|
|
|
|
if (!fields_str)
|
|
|
|
|
goto out;
|
|
|
|
|
|
|
|
|
|
strsep(&fields_str, "=");
|
|
|
|
|
if (!fields_str) {
|
|
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < TRACING_MAP_SORT_KEYS_MAX; i++) {
|
2017-09-23 03:58:22 +08:00
|
|
|
struct hist_field *hist_field;
|
2016-03-04 02:54:45 +08:00
|
|
|
char *field_str, *field_name;
|
2017-09-23 03:58:22 +08:00
|
|
|
const char *test_name;
|
2016-03-04 02:54:45 +08:00
|
|
|
|
|
|
|
|
sort_key = &hist_data->sort_keys[i];
|
|
|
|
|
|
|
|
|
|
field_str = strsep(&fields_str, ",");
|
|
|
|
|
if (!field_str) {
|
|
|
|
|
if (i == 0)
|
|
|
|
|
ret = -EINVAL;
|
|
|
|
|
break;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if ((i == TRACING_MAP_SORT_KEYS_MAX - 1) && fields_str) {
|
|
|
|
|
ret = -EINVAL;
|
|
|
|
|
break;
|
|
|
|
|
}
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
|
2016-03-04 02:54:45 +08:00
|
|
|
field_name = strsep(&field_str, ".");
|
|
|
|
|
if (!field_name) {
|
|
|
|
|
ret = -EINVAL;
|
|
|
|
|
break;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if (strcmp(field_name, "hitcount") == 0) {
|
|
|
|
|
descending = is_descending(field_str);
|
|
|
|
|
if (descending < 0) {
|
|
|
|
|
ret = descending;
|
|
|
|
|
break;
|
|
|
|
|
}
|
|
|
|
|
sort_key->descending = descending;
|
|
|
|
|
continue;
|
|
|
|
|
}
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
|
2018-01-16 10:51:49 +08:00
|
|
|
for (j = 1, k = 1; j < hist_data->n_fields; j++) {
|
|
|
|
|
unsigned int idx;
|
|
|
|
|
|
2017-09-23 03:58:22 +08:00
|
|
|
hist_field = hist_data->fields[j];
|
2018-01-16 10:51:49 +08:00
|
|
|
if (hist_field->flags & HIST_FIELD_FL_VAR)
|
|
|
|
|
continue;
|
|
|
|
|
|
|
|
|
|
idx = k++;
|
|
|
|
|
|
2017-09-23 03:58:22 +08:00
|
|
|
test_name = hist_field_name(hist_field, 0);
|
|
|
|
|
|
|
|
|
|
if (strcmp(field_name, test_name) == 0) {
|
2018-01-16 10:51:49 +08:00
|
|
|
sort_key->field_idx = idx;
|
2016-03-04 02:54:45 +08:00
|
|
|
descending = is_descending(field_str);
|
|
|
|
|
if (descending < 0) {
|
|
|
|
|
ret = descending;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
sort_key->descending = descending;
|
|
|
|
|
break;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
if (j == hist_data->n_fields) {
|
|
|
|
|
ret = -EINVAL;
|
|
|
|
|
break;
|
|
|
|
|
}
|
|
|
|
|
}
|
2018-01-16 10:51:49 +08:00
|
|
|
|
2016-03-04 02:54:45 +08:00
|
|
|
hist_data->n_sort_keys = i;
|
|
|
|
|
out:
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:51:57 +08:00
|
|
|
static void destroy_actions(struct hist_trigger_data *hist_data)
|
|
|
|
|
{
|
|
|
|
|
unsigned int i;
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < hist_data->n_actions; i++) {
|
|
|
|
|
struct action_data *data = hist_data->actions[i];
|
|
|
|
|
|
2018-01-16 10:52:00 +08:00
|
|
|
if (data->fn == action_trace)
|
|
|
|
|
onmatch_destroy(data);
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:52:01 +08:00
|
|
|
else if (data->fn == onmax_save)
|
|
|
|
|
onmax_destroy(data);
|
2018-01-16 10:52:00 +08:00
|
|
|
else
|
|
|
|
|
kfree(data);
|
2018-01-16 10:51:57 +08:00
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int parse_actions(struct hist_trigger_data *hist_data)
|
|
|
|
|
{
|
2018-01-16 10:52:00 +08:00
|
|
|
struct trace_array *tr = hist_data->event_file->tr;
|
|
|
|
|
struct action_data *data;
|
2018-01-16 10:51:57 +08:00
|
|
|
unsigned int i;
|
|
|
|
|
int ret = 0;
|
|
|
|
|
char *str;
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < hist_data->attrs->n_actions; i++) {
|
|
|
|
|
str = hist_data->attrs->action_str[i];
|
2018-01-16 10:52:00 +08:00
|
|
|
|
|
|
|
|
if (strncmp(str, "onmatch(", strlen("onmatch(")) == 0) {
|
|
|
|
|
char *action_str = str + strlen("onmatch(");
|
|
|
|
|
|
|
|
|
|
data = onmatch_parse(tr, action_str);
|
|
|
|
|
if (IS_ERR(data)) {
|
|
|
|
|
ret = PTR_ERR(data);
|
|
|
|
|
break;
|
|
|
|
|
}
|
|
|
|
|
data->fn = action_trace;
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:52:01 +08:00
|
|
|
} else if (strncmp(str, "onmax(", strlen("onmax(")) == 0) {
|
|
|
|
|
char *action_str = str + strlen("onmax(");
|
|
|
|
|
|
|
|
|
|
data = onmax_parse(action_str);
|
|
|
|
|
if (IS_ERR(data)) {
|
|
|
|
|
ret = PTR_ERR(data);
|
|
|
|
|
break;
|
|
|
|
|
}
|
|
|
|
|
data->fn = onmax_save;
|
2018-01-16 10:52:00 +08:00
|
|
|
} else {
|
|
|
|
|
ret = -EINVAL;
|
|
|
|
|
break;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
hist_data->actions[hist_data->n_actions++] = data;
|
2018-01-16 10:51:57 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int create_actions(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct trace_event_file *file)
|
|
|
|
|
{
|
|
|
|
|
struct action_data *data;
|
|
|
|
|
unsigned int i;
|
|
|
|
|
int ret = 0;
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < hist_data->attrs->n_actions; i++) {
|
|
|
|
|
data = hist_data->actions[i];
|
2018-01-16 10:52:00 +08:00
|
|
|
|
|
|
|
|
if (data->fn == action_trace) {
|
|
|
|
|
ret = onmatch_create(hist_data, file, data);
|
|
|
|
|
if (ret)
|
|
|
|
|
return ret;
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:52:01 +08:00
|
|
|
} else if (data->fn == onmax_save) {
|
|
|
|
|
ret = onmax_create(hist_data, data);
|
|
|
|
|
if (ret)
|
|
|
|
|
return ret;
|
2018-01-16 10:52:00 +08:00
|
|
|
}
|
2018-01-16 10:51:57 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:52:01 +08:00
|
|
|
static void print_actions(struct seq_file *m,
|
|
|
|
|
struct hist_trigger_data *hist_data,
|
|
|
|
|
struct tracing_map_elt *elt)
|
|
|
|
|
{
|
|
|
|
|
unsigned int i;
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < hist_data->n_actions; i++) {
|
|
|
|
|
struct action_data *data = hist_data->actions[i];
|
|
|
|
|
|
|
|
|
|
if (data->fn == onmax_save)
|
|
|
|
|
onmax_print(m, hist_data, elt, data);
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void print_onmax_spec(struct seq_file *m,
|
|
|
|
|
struct hist_trigger_data *hist_data,
|
|
|
|
|
struct action_data *data)
|
|
|
|
|
{
|
|
|
|
|
unsigned int i;
|
|
|
|
|
|
|
|
|
|
seq_puts(m, ":onmax(");
|
|
|
|
|
seq_printf(m, "%s", data->onmax.var_str);
|
|
|
|
|
seq_printf(m, ").%s(", data->onmax.fn_name);
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < hist_data->n_max_vars; i++) {
|
|
|
|
|
seq_printf(m, "%s", hist_data->max_vars[i]->var->var.name);
|
|
|
|
|
if (i < hist_data->n_max_vars - 1)
|
|
|
|
|
seq_puts(m, ",");
|
|
|
|
|
}
|
|
|
|
|
seq_puts(m, ")");
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:52:00 +08:00
|
|
|
static void print_onmatch_spec(struct seq_file *m,
|
|
|
|
|
struct hist_trigger_data *hist_data,
|
|
|
|
|
struct action_data *data)
|
|
|
|
|
{
|
|
|
|
|
unsigned int i;
|
|
|
|
|
|
|
|
|
|
seq_printf(m, ":onmatch(%s.%s).", data->onmatch.match_event_system,
|
|
|
|
|
data->onmatch.match_event);
|
|
|
|
|
|
|
|
|
|
seq_printf(m, "%s(", data->onmatch.synth_event->name);
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < data->n_params; i++) {
|
|
|
|
|
if (i)
|
|
|
|
|
seq_puts(m, ",");
|
|
|
|
|
seq_printf(m, "%s", data->params[i]);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
seq_puts(m, ")");
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void print_actions_spec(struct seq_file *m,
|
|
|
|
|
struct hist_trigger_data *hist_data)
|
|
|
|
|
{
|
|
|
|
|
unsigned int i;
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < hist_data->n_actions; i++) {
|
|
|
|
|
struct action_data *data = hist_data->actions[i];
|
|
|
|
|
|
|
|
|
|
if (data->fn == action_trace)
|
|
|
|
|
print_onmatch_spec(m, hist_data, data);
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:52:01 +08:00
|
|
|
else if (data->fn == onmax_save)
|
|
|
|
|
print_onmax_spec(m, hist_data, data);
|
2018-01-16 10:52:00 +08:00
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:51:59 +08:00
|
|
|
static void destroy_field_var_hists(struct hist_trigger_data *hist_data)
|
|
|
|
|
{
|
|
|
|
|
unsigned int i;
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < hist_data->n_field_var_hists; i++) {
|
|
|
|
|
kfree(hist_data->field_var_hists[i]->cmd);
|
|
|
|
|
kfree(hist_data->field_var_hists[i]);
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
static void destroy_hist_data(struct hist_trigger_data *hist_data)
|
|
|
|
|
{
|
2018-01-16 10:51:57 +08:00
|
|
|
if (!hist_data)
|
|
|
|
|
return;
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
destroy_hist_trigger_attrs(hist_data->attrs);
|
|
|
|
|
destroy_hist_fields(hist_data);
|
|
|
|
|
tracing_map_destroy(hist_data->map);
|
2018-01-16 10:51:57 +08:00
|
|
|
|
|
|
|
|
destroy_actions(hist_data);
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:51:59 +08:00
|
|
|
destroy_field_vars(hist_data);
|
|
|
|
|
destroy_field_var_hists(hist_data);
|
2018-01-16 10:52:00 +08:00
|
|
|
destroy_synth_var_refs(hist_data);
|
2018-01-16 10:51:57 +08:00
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
kfree(hist_data);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int create_tracing_map_fields(struct hist_trigger_data *hist_data)
|
|
|
|
|
{
|
|
|
|
|
struct tracing_map *map = hist_data->map;
|
|
|
|
|
struct ftrace_event_field *field;
|
|
|
|
|
struct hist_field *hist_field;
|
2016-03-09 06:17:15 +08:00
|
|
|
int i, idx;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
|
|
|
|
|
for_each_hist_field(i, hist_data) {
|
|
|
|
|
hist_field = hist_data->fields[i];
|
|
|
|
|
if (hist_field->flags & HIST_FIELD_FL_KEY) {
|
|
|
|
|
tracing_map_cmp_fn_t cmp_fn;
|
|
|
|
|
|
|
|
|
|
field = hist_field->field;
|
|
|
|
|
|
2016-03-04 02:54:52 +08:00
|
|
|
if (hist_field->flags & HIST_FIELD_FL_STACKTRACE)
|
|
|
|
|
cmp_fn = tracing_map_cmp_none;
|
2018-01-16 10:51:45 +08:00
|
|
|
else if (!field)
|
|
|
|
|
cmp_fn = tracing_map_cmp_num(hist_field->size,
|
|
|
|
|
hist_field->is_signed);
|
2016-03-04 02:54:52 +08:00
|
|
|
else if (is_string_field(field))
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
cmp_fn = tracing_map_cmp_string;
|
|
|
|
|
else
|
|
|
|
|
cmp_fn = tracing_map_cmp_num(field->size,
|
|
|
|
|
field->is_signed);
|
2016-03-04 02:54:44 +08:00
|
|
|
idx = tracing_map_add_key_field(map,
|
|
|
|
|
hist_field->offset,
|
|
|
|
|
cmp_fn);
|
2018-01-16 10:51:49 +08:00
|
|
|
} else if (!(hist_field->flags & HIST_FIELD_FL_VAR))
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
idx = tracing_map_add_sum_field(map);
|
|
|
|
|
|
|
|
|
|
if (idx < 0)
|
|
|
|
|
return idx;
|
2018-01-16 10:51:49 +08:00
|
|
|
|
|
|
|
|
if (hist_field->flags & HIST_FIELD_FL_VAR) {
|
|
|
|
|
idx = tracing_map_add_var(map);
|
|
|
|
|
if (idx < 0)
|
|
|
|
|
return idx;
|
|
|
|
|
hist_field->var.idx = idx;
|
|
|
|
|
hist_field->var.hist_data = hist_data;
|
|
|
|
|
}
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static struct hist_trigger_data *
|
|
|
|
|
create_hist_data(unsigned int map_bits,
|
|
|
|
|
struct hist_trigger_attrs *attrs,
|
2018-01-16 10:51:49 +08:00
|
|
|
struct trace_event_file *file,
|
|
|
|
|
bool remove)
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
{
|
2016-03-04 02:54:50 +08:00
|
|
|
const struct tracing_map_ops *map_ops = NULL;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
struct hist_trigger_data *hist_data;
|
|
|
|
|
int ret = 0;
|
|
|
|
|
|
|
|
|
|
hist_data = kzalloc(sizeof(*hist_data), GFP_KERNEL);
|
|
|
|
|
if (!hist_data)
|
|
|
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
|
|
|
|
|
|
hist_data->attrs = attrs;
|
2018-01-16 10:51:49 +08:00
|
|
|
hist_data->remove = remove;
|
2018-01-16 10:51:56 +08:00
|
|
|
hist_data->event_file = file;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
|
2018-01-16 10:51:57 +08:00
|
|
|
ret = parse_actions(hist_data);
|
|
|
|
|
if (ret)
|
|
|
|
|
goto free;
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
ret = create_hist_fields(hist_data, file);
|
|
|
|
|
if (ret)
|
|
|
|
|
goto free;
|
|
|
|
|
|
|
|
|
|
ret = create_sort_keys(hist_data);
|
|
|
|
|
if (ret)
|
|
|
|
|
goto free;
|
|
|
|
|
|
2018-01-16 10:51:53 +08:00
|
|
|
map_ops = &hist_trigger_elt_data_ops;
|
2016-03-04 02:54:50 +08:00
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
hist_data->map = tracing_map_create(map_bits, hist_data->key_size,
|
2016-03-04 02:54:50 +08:00
|
|
|
map_ops, hist_data);
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
if (IS_ERR(hist_data->map)) {
|
|
|
|
|
ret = PTR_ERR(hist_data->map);
|
|
|
|
|
hist_data->map = NULL;
|
|
|
|
|
goto free;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
ret = create_tracing_map_fields(hist_data);
|
|
|
|
|
if (ret)
|
|
|
|
|
goto free;
|
|
|
|
|
out:
|
|
|
|
|
return hist_data;
|
|
|
|
|
free:
|
|
|
|
|
hist_data->attrs = NULL;
|
|
|
|
|
|
|
|
|
|
destroy_hist_data(hist_data);
|
|
|
|
|
|
|
|
|
|
hist_data = ERR_PTR(ret);
|
|
|
|
|
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void hist_trigger_elt_update(struct hist_trigger_data *hist_data,
|
2018-01-16 10:51:43 +08:00
|
|
|
struct tracing_map_elt *elt, void *rec,
|
2018-01-16 10:51:56 +08:00
|
|
|
struct ring_buffer_event *rbe,
|
|
|
|
|
u64 *var_ref_vals)
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
{
|
2018-01-16 10:51:56 +08:00
|
|
|
struct hist_elt_data *elt_data;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
struct hist_field *hist_field;
|
2018-01-16 10:51:49 +08:00
|
|
|
unsigned int i, var_idx;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
u64 hist_val;
|
|
|
|
|
|
2018-01-16 10:51:56 +08:00
|
|
|
elt_data = elt->private_data;
|
|
|
|
|
elt_data->var_ref_vals = var_ref_vals;
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
for_each_hist_val_field(i, hist_data) {
|
|
|
|
|
hist_field = hist_data->fields[i];
|
2018-01-16 10:51:54 +08:00
|
|
|
hist_val = hist_field->fn(hist_field, elt, rbe, rec);
|
2018-01-16 10:51:49 +08:00
|
|
|
if (hist_field->flags & HIST_FIELD_FL_VAR) {
|
|
|
|
|
var_idx = hist_field->var.idx;
|
|
|
|
|
tracing_map_set_var(elt, var_idx, hist_val);
|
|
|
|
|
continue;
|
|
|
|
|
}
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
tracing_map_update_sum(elt, i, hist_val);
|
|
|
|
|
}
|
2018-01-16 10:51:49 +08:00
|
|
|
|
|
|
|
|
for_each_hist_key_field(i, hist_data) {
|
|
|
|
|
hist_field = hist_data->fields[i];
|
|
|
|
|
if (hist_field->flags & HIST_FIELD_FL_VAR) {
|
2018-01-16 10:51:54 +08:00
|
|
|
hist_val = hist_field->fn(hist_field, elt, rbe, rec);
|
2018-01-16 10:51:49 +08:00
|
|
|
var_idx = hist_field->var.idx;
|
|
|
|
|
tracing_map_set_var(elt, var_idx, hist_val);
|
|
|
|
|
}
|
|
|
|
|
}
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:51:59 +08:00
|
|
|
|
|
|
|
|
update_field_vars(hist_data, elt, rbe, rec);
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
}
|
|
|
|
|
|
2016-03-04 02:54:54 +08:00
|
|
|
static inline void add_to_key(char *compound_key, void *key,
|
|
|
|
|
struct hist_field *key_field, void *rec)
|
|
|
|
|
{
|
|
|
|
|
size_t size = key_field->size;
|
|
|
|
|
|
|
|
|
|
if (key_field->flags & HIST_FIELD_FL_STRING) {
|
|
|
|
|
struct ftrace_event_field *field;
|
|
|
|
|
|
|
|
|
|
field = key_field->field;
|
|
|
|
|
if (field->filter_type == FILTER_DYN_STRING)
|
|
|
|
|
size = *(u32 *)(rec + field->offset) >> 16;
|
|
|
|
|
else if (field->filter_type == FILTER_PTR_STRING)
|
|
|
|
|
size = strlen(key);
|
|
|
|
|
else if (field->filter_type == FILTER_STATIC_STRING)
|
|
|
|
|
size = field->size;
|
|
|
|
|
|
|
|
|
|
/* ensure NULL-termination */
|
|
|
|
|
if (size > key_field->size - 1)
|
|
|
|
|
size = key_field->size - 1;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
memcpy(compound_key + key_field->offset, key, size);
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:51:57 +08:00
|
|
|
static void
|
|
|
|
|
hist_trigger_actions(struct hist_trigger_data *hist_data,
|
|
|
|
|
struct tracing_map_elt *elt, void *rec,
|
|
|
|
|
struct ring_buffer_event *rbe, u64 *var_ref_vals)
|
|
|
|
|
{
|
|
|
|
|
struct action_data *data;
|
|
|
|
|
unsigned int i;
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < hist_data->n_actions; i++) {
|
|
|
|
|
data = hist_data->actions[i];
|
|
|
|
|
data->fn(hist_data, elt, rec, rbe, data, var_ref_vals);
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:51:42 +08:00
|
|
|
static void event_hist_trigger(struct event_trigger_data *data, void *rec,
|
2018-01-16 10:51:43 +08:00
|
|
|
struct ring_buffer_event *rbe)
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
{
|
|
|
|
|
struct hist_trigger_data *hist_data = data->private_data;
|
2016-03-04 02:54:54 +08:00
|
|
|
bool use_compound_key = (hist_data->n_keys > 1);
|
2016-03-04 02:54:52 +08:00
|
|
|
unsigned long entries[HIST_STACKTRACE_DEPTH];
|
2018-01-16 10:51:56 +08:00
|
|
|
u64 var_ref_vals[TRACING_MAP_VARS_MAX];
|
2016-03-04 02:54:44 +08:00
|
|
|
char compound_key[HIST_KEY_SIZE_MAX];
|
2018-01-16 10:51:54 +08:00
|
|
|
struct tracing_map_elt *elt = NULL;
|
2016-03-04 02:54:52 +08:00
|
|
|
struct stack_trace stacktrace;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
struct hist_field *key_field;
|
|
|
|
|
u64 field_contents;
|
|
|
|
|
void *key = NULL;
|
|
|
|
|
unsigned int i;
|
|
|
|
|
|
2016-03-04 02:54:54 +08:00
|
|
|
memset(compound_key, 0, hist_data->key_size);
|
2016-03-04 02:54:44 +08:00
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
for_each_hist_key_field(i, hist_data) {
|
|
|
|
|
key_field = hist_data->fields[i];
|
|
|
|
|
|
2016-03-04 02:54:52 +08:00
|
|
|
if (key_field->flags & HIST_FIELD_FL_STACKTRACE) {
|
|
|
|
|
stacktrace.max_entries = HIST_STACKTRACE_DEPTH;
|
|
|
|
|
stacktrace.entries = entries;
|
|
|
|
|
stacktrace.nr_entries = 0;
|
|
|
|
|
stacktrace.skip = HIST_STACKTRACE_SKIP;
|
2016-03-04 02:54:44 +08:00
|
|
|
|
2016-03-04 02:54:52 +08:00
|
|
|
memset(stacktrace.entries, 0, HIST_STACKTRACE_SIZE);
|
|
|
|
|
save_stack_trace(&stacktrace);
|
|
|
|
|
|
|
|
|
|
key = entries;
|
|
|
|
|
} else {
|
2018-01-16 10:51:54 +08:00
|
|
|
field_contents = key_field->fn(key_field, elt, rbe, rec);
|
2016-03-04 02:54:54 +08:00
|
|
|
if (key_field->flags & HIST_FIELD_FL_STRING) {
|
2016-03-04 02:54:52 +08:00
|
|
|
key = (void *)(unsigned long)field_contents;
|
2016-03-04 02:54:54 +08:00
|
|
|
use_compound_key = true;
|
|
|
|
|
} else
|
2016-03-04 02:54:52 +08:00
|
|
|
key = (void *)&field_contents;
|
2016-03-04 02:54:44 +08:00
|
|
|
}
|
2016-03-04 02:54:54 +08:00
|
|
|
|
|
|
|
|
if (use_compound_key)
|
|
|
|
|
add_to_key(compound_key, key, key_field, rec);
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
}
|
|
|
|
|
|
2016-03-04 02:54:54 +08:00
|
|
|
if (use_compound_key)
|
2016-03-04 02:54:44 +08:00
|
|
|
key = compound_key;
|
|
|
|
|
|
2018-01-16 10:51:56 +08:00
|
|
|
if (hist_data->n_var_refs &&
|
|
|
|
|
!resolve_var_refs(hist_data, key, var_ref_vals, false))
|
|
|
|
|
return;
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
elt = tracing_map_insert(hist_data->map, key);
|
2018-01-16 10:51:56 +08:00
|
|
|
if (!elt)
|
|
|
|
|
return;
|
|
|
|
|
|
|
|
|
|
hist_trigger_elt_update(hist_data, elt, rec, rbe, var_ref_vals);
|
2018-01-16 10:51:57 +08:00
|
|
|
|
|
|
|
|
if (resolve_var_refs(hist_data, key, var_ref_vals, true))
|
|
|
|
|
hist_trigger_actions(hist_data, elt, rec, rbe, var_ref_vals);
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
}
|
|
|
|
|
|
2016-03-04 02:54:52 +08:00
|
|
|
static void hist_trigger_stacktrace_print(struct seq_file *m,
|
|
|
|
|
unsigned long *stacktrace_entries,
|
|
|
|
|
unsigned int max_entries)
|
|
|
|
|
{
|
|
|
|
|
char str[KSYM_SYMBOL_LEN];
|
|
|
|
|
unsigned int spaces = 8;
|
|
|
|
|
unsigned int i;
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < max_entries; i++) {
|
|
|
|
|
if (stacktrace_entries[i] == ULONG_MAX)
|
|
|
|
|
return;
|
|
|
|
|
|
|
|
|
|
seq_printf(m, "%*c", 1 + spaces, ' ');
|
|
|
|
|
sprint_symbol(str, stacktrace_entries[i]);
|
|
|
|
|
seq_printf(m, "%s\n", str);
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
static void
|
|
|
|
|
hist_trigger_entry_print(struct seq_file *m,
|
|
|
|
|
struct hist_trigger_data *hist_data, void *key,
|
|
|
|
|
struct tracing_map_elt *elt)
|
|
|
|
|
{
|
|
|
|
|
struct hist_field *key_field;
|
2016-03-04 02:54:49 +08:00
|
|
|
char str[KSYM_SYMBOL_LEN];
|
2016-03-04 02:54:52 +08:00
|
|
|
bool multiline = false;
|
2017-09-23 03:58:22 +08:00
|
|
|
const char *field_name;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
unsigned int i;
|
|
|
|
|
u64 uval;
|
|
|
|
|
|
|
|
|
|
seq_puts(m, "{ ");
|
|
|
|
|
|
|
|
|
|
for_each_hist_key_field(i, hist_data) {
|
|
|
|
|
key_field = hist_data->fields[i];
|
|
|
|
|
|
|
|
|
|
if (i > hist_data->n_vals)
|
|
|
|
|
seq_puts(m, ", ");
|
|
|
|
|
|
2017-09-23 03:58:22 +08:00
|
|
|
field_name = hist_field_name(key_field, 0);
|
|
|
|
|
|
2016-03-04 02:54:48 +08:00
|
|
|
if (key_field->flags & HIST_FIELD_FL_HEX) {
|
|
|
|
|
uval = *(u64 *)(key + key_field->offset);
|
2017-09-23 03:58:22 +08:00
|
|
|
seq_printf(m, "%s: %llx", field_name, uval);
|
2016-03-04 02:54:49 +08:00
|
|
|
} else if (key_field->flags & HIST_FIELD_FL_SYM) {
|
|
|
|
|
uval = *(u64 *)(key + key_field->offset);
|
|
|
|
|
sprint_symbol_no_offset(str, uval);
|
2017-09-23 03:58:22 +08:00
|
|
|
seq_printf(m, "%s: [%llx] %-45s", field_name,
|
|
|
|
|
uval, str);
|
2016-03-04 02:54:49 +08:00
|
|
|
} else if (key_field->flags & HIST_FIELD_FL_SYM_OFFSET) {
|
|
|
|
|
uval = *(u64 *)(key + key_field->offset);
|
|
|
|
|
sprint_symbol(str, uval);
|
2017-09-23 03:58:22 +08:00
|
|
|
seq_printf(m, "%s: [%llx] %-55s", field_name,
|
|
|
|
|
uval, str);
|
2016-03-04 02:54:50 +08:00
|
|
|
} else if (key_field->flags & HIST_FIELD_FL_EXECNAME) {
|
2018-01-16 10:51:53 +08:00
|
|
|
struct hist_elt_data *elt_data = elt->private_data;
|
|
|
|
|
char *comm;
|
|
|
|
|
|
|
|
|
|
if (WARN_ON_ONCE(!elt_data))
|
|
|
|
|
return;
|
|
|
|
|
|
|
|
|
|
comm = elt_data->comm;
|
2016-03-04 02:54:50 +08:00
|
|
|
|
|
|
|
|
uval = *(u64 *)(key + key_field->offset);
|
2017-09-23 03:58:22 +08:00
|
|
|
seq_printf(m, "%s: %-16s[%10llu]", field_name,
|
|
|
|
|
comm, uval);
|
2016-03-04 02:54:51 +08:00
|
|
|
} else if (key_field->flags & HIST_FIELD_FL_SYSCALL) {
|
|
|
|
|
const char *syscall_name;
|
|
|
|
|
|
|
|
|
|
uval = *(u64 *)(key + key_field->offset);
|
|
|
|
|
syscall_name = get_syscall_name(uval);
|
|
|
|
|
if (!syscall_name)
|
|
|
|
|
syscall_name = "unknown_syscall";
|
|
|
|
|
|
2017-09-23 03:58:22 +08:00
|
|
|
seq_printf(m, "%s: %-30s[%3llu]", field_name,
|
|
|
|
|
syscall_name, uval);
|
2016-03-04 02:54:52 +08:00
|
|
|
} else if (key_field->flags & HIST_FIELD_FL_STACKTRACE) {
|
|
|
|
|
seq_puts(m, "stacktrace:\n");
|
|
|
|
|
hist_trigger_stacktrace_print(m,
|
|
|
|
|
key + key_field->offset,
|
|
|
|
|
HIST_STACKTRACE_DEPTH);
|
|
|
|
|
multiline = true;
|
2016-03-04 02:55:02 +08:00
|
|
|
} else if (key_field->flags & HIST_FIELD_FL_LOG2) {
|
2017-09-23 03:58:22 +08:00
|
|
|
seq_printf(m, "%s: ~ 2^%-2llu", field_name,
|
2016-03-04 02:55:02 +08:00
|
|
|
*(u64 *)(key + key_field->offset));
|
2016-03-04 02:54:48 +08:00
|
|
|
} else if (key_field->flags & HIST_FIELD_FL_STRING) {
|
2017-09-23 03:58:22 +08:00
|
|
|
seq_printf(m, "%s: %-50s", field_name,
|
2016-03-04 02:54:44 +08:00
|
|
|
(char *)(key + key_field->offset));
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
} else {
|
2016-03-04 02:54:44 +08:00
|
|
|
uval = *(u64 *)(key + key_field->offset);
|
2017-09-23 03:58:22 +08:00
|
|
|
seq_printf(m, "%s: %10llu", field_name, uval);
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
2016-03-04 02:54:52 +08:00
|
|
|
if (!multiline)
|
|
|
|
|
seq_puts(m, " ");
|
|
|
|
|
|
|
|
|
|
seq_puts(m, "}");
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
|
|
|
|
|
seq_printf(m, " hitcount: %10llu",
|
|
|
|
|
tracing_map_read_sum(elt, HITCOUNT_IDX));
|
|
|
|
|
|
2016-03-04 02:54:43 +08:00
|
|
|
for (i = 1; i < hist_data->n_vals; i++) {
|
2017-09-23 03:58:22 +08:00
|
|
|
field_name = hist_field_name(hist_data->fields[i], 0);
|
|
|
|
|
|
2018-01-16 10:51:52 +08:00
|
|
|
if (hist_data->fields[i]->flags & HIST_FIELD_FL_VAR ||
|
|
|
|
|
hist_data->fields[i]->flags & HIST_FIELD_FL_EXPR)
|
2018-01-16 10:51:49 +08:00
|
|
|
continue;
|
|
|
|
|
|
2016-03-04 02:54:48 +08:00
|
|
|
if (hist_data->fields[i]->flags & HIST_FIELD_FL_HEX) {
|
2017-09-23 03:58:22 +08:00
|
|
|
seq_printf(m, " %s: %10llx", field_name,
|
2016-03-04 02:54:48 +08:00
|
|
|
tracing_map_read_sum(elt, i));
|
|
|
|
|
} else {
|
2017-09-23 03:58:22 +08:00
|
|
|
seq_printf(m, " %s: %10llu", field_name,
|
2016-03-04 02:54:48 +08:00
|
|
|
tracing_map_read_sum(elt, i));
|
|
|
|
|
}
|
2016-03-04 02:54:43 +08:00
|
|
|
}
|
|
|
|
|
|
tracing: Add 'onmax' hist trigger action support
Add an 'onmax(var).save(field,...)' hist trigger action which is
invoked whenever an event exceeds the current maximum.
The end result is that the trace event fields or variables specified
as the onmax.save() params will be saved if 'var' exceeds the current
maximum for that hist trigger entry. This allows context from the
event that exhibited the new maximum to be saved for later reference.
When the histogram is displayed, additional fields displaying the
saved values will be printed.
As an example the below defines a couple of hist triggers, one for
sched_wakeup and another for sched_switch, keyed on pid. Whenever a
sched_wakeup occurs, the timestamp is saved in the entry corresponding
to the current pid, and when the scheduler switches back to that pid,
the timestamp difference is calculated. If the resulting latency
exceeds the current maximum latency, the specified save() values are
saved:
# echo 'hist:keys=pid:ts0=common_timestamp.usecs \
if comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_wakeup/trigger
# echo 'hist:keys=next_pid:\
wakeup_lat=common_timestamp.usecs-$ts0:\
onmax($wakeup_lat).save(next_comm,prev_pid,prev_prio,prev_comm) \
if next_comm=="cyclictest"' >> \
/sys/kernel/debug/tracing/events/sched/sched_switch/trigger
When the histogram is displayed, the max value and the saved values
corresponding to the max are displayed following the rest of the
fields:
# cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist
{ next_pid: 3728 } hitcount: 199 \
max: 123 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/3
{ next_pid: 3730 } hitcount: 1321 \
max: 15 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/1
{ next_pid: 3729 } hitcount: 1973\
max: 25 next_comm: cyclictest prev_pid: 0 \
prev_prio: 120 prev_comm: swapper/0
Totals:
Hits: 3493
Entries: 3
Dropped: 0
Link: http://lkml.kernel.org/r/006907f71b1e839bb059337ec3c496f84fcb71de.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:52:01 +08:00
|
|
|
print_actions(m, hist_data, elt);
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
seq_puts(m, "\n");
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int print_entries(struct seq_file *m,
|
|
|
|
|
struct hist_trigger_data *hist_data)
|
|
|
|
|
{
|
|
|
|
|
struct tracing_map_sort_entry **sort_entries = NULL;
|
|
|
|
|
struct tracing_map *map = hist_data->map;
|
2016-03-09 06:17:15 +08:00
|
|
|
int i, n_entries;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
|
|
|
|
|
n_entries = tracing_map_sort_entries(map, hist_data->sort_keys,
|
|
|
|
|
hist_data->n_sort_keys,
|
|
|
|
|
&sort_entries);
|
|
|
|
|
if (n_entries < 0)
|
|
|
|
|
return n_entries;
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < n_entries; i++)
|
|
|
|
|
hist_trigger_entry_print(m, hist_data,
|
|
|
|
|
sort_entries[i]->key,
|
|
|
|
|
sort_entries[i]->elt);
|
|
|
|
|
|
|
|
|
|
tracing_map_destroy_sort_entries(sort_entries, n_entries);
|
|
|
|
|
|
|
|
|
|
return n_entries;
|
|
|
|
|
}
|
|
|
|
|
|
2016-03-04 02:54:57 +08:00
|
|
|
static void hist_trigger_show(struct seq_file *m,
|
|
|
|
|
struct event_trigger_data *data, int n)
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
{
|
|
|
|
|
struct hist_trigger_data *hist_data;
|
2017-08-23 19:23:09 +08:00
|
|
|
int n_entries;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
|
2016-03-04 02:54:57 +08:00
|
|
|
if (n > 0)
|
|
|
|
|
seq_puts(m, "\n\n");
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
|
|
|
|
|
seq_puts(m, "# event histogram\n#\n# trigger info: ");
|
|
|
|
|
data->ops->print(m, data->ops, data);
|
2016-03-04 02:54:57 +08:00
|
|
|
seq_puts(m, "#\n\n");
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
|
|
|
|
|
hist_data = data->private_data;
|
|
|
|
|
n_entries = print_entries(m, hist_data);
|
2017-08-23 19:23:09 +08:00
|
|
|
if (n_entries < 0)
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
n_entries = 0;
|
|
|
|
|
|
|
|
|
|
seq_printf(m, "\nTotals:\n Hits: %llu\n Entries: %u\n Dropped: %llu\n",
|
|
|
|
|
(u64)atomic64_read(&hist_data->map->hits),
|
|
|
|
|
n_entries, (u64)atomic64_read(&hist_data->map->drops));
|
2016-03-04 02:54:57 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int hist_show(struct seq_file *m, void *v)
|
|
|
|
|
{
|
|
|
|
|
struct event_trigger_data *data;
|
|
|
|
|
struct trace_event_file *event_file;
|
|
|
|
|
int n = 0, ret = 0;
|
|
|
|
|
|
|
|
|
|
mutex_lock(&event_mutex);
|
|
|
|
|
|
|
|
|
|
event_file = event_file_data(m->private);
|
|
|
|
|
if (unlikely(!event_file)) {
|
|
|
|
|
ret = -ENODEV;
|
|
|
|
|
goto out_unlock;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
list_for_each_entry_rcu(data, &event_file->triggers, list) {
|
|
|
|
|
if (data->cmd_ops->trigger_type == ETT_EVENT_HIST)
|
|
|
|
|
hist_trigger_show(m, data, n++);
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:52:05 +08:00
|
|
|
if (have_hist_err()) {
|
|
|
|
|
seq_printf(m, "\nERROR: %s\n", hist_err_str);
|
|
|
|
|
seq_printf(m, " Last command: %s\n", last_hist_cmd);
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
out_unlock:
|
|
|
|
|
mutex_unlock(&event_mutex);
|
|
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int event_hist_open(struct inode *inode, struct file *file)
|
|
|
|
|
{
|
|
|
|
|
return single_open(file, hist_show, file);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
const struct file_operations event_hist_fops = {
|
|
|
|
|
.open = event_hist_open,
|
|
|
|
|
.read = seq_read,
|
|
|
|
|
.llseek = seq_lseek,
|
|
|
|
|
.release = single_release,
|
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
static void hist_field_print(struct seq_file *m, struct hist_field *hist_field)
|
|
|
|
|
{
|
2017-09-23 03:58:22 +08:00
|
|
|
const char *field_name = hist_field_name(hist_field, 0);
|
|
|
|
|
|
2018-01-16 10:51:49 +08:00
|
|
|
if (hist_field->var.name)
|
|
|
|
|
seq_printf(m, "%s=", hist_field->var.name);
|
|
|
|
|
|
2018-01-16 10:51:45 +08:00
|
|
|
if (hist_field->flags & HIST_FIELD_FL_TIMESTAMP)
|
|
|
|
|
seq_puts(m, "common_timestamp");
|
2018-01-16 10:52:03 +08:00
|
|
|
else if (hist_field->flags & HIST_FIELD_FL_CPU)
|
|
|
|
|
seq_puts(m, "cpu");
|
2018-01-16 10:51:56 +08:00
|
|
|
else if (field_name) {
|
2018-01-16 10:52:04 +08:00
|
|
|
if (hist_field->flags & HIST_FIELD_FL_VAR_REF ||
|
|
|
|
|
hist_field->flags & HIST_FIELD_FL_ALIAS)
|
2018-01-16 10:51:56 +08:00
|
|
|
seq_putc(m, '$');
|
2018-01-16 10:51:45 +08:00
|
|
|
seq_printf(m, "%s", field_name);
|
2018-01-16 10:51:56 +08:00
|
|
|
}
|
2018-01-16 10:51:45 +08:00
|
|
|
|
2016-03-04 02:54:48 +08:00
|
|
|
if (hist_field->flags) {
|
|
|
|
|
const char *flags_str = get_hist_field_flags(hist_field);
|
|
|
|
|
|
|
|
|
|
if (flags_str)
|
|
|
|
|
seq_printf(m, ".%s", flags_str);
|
|
|
|
|
}
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int event_hist_trigger_print(struct seq_file *m,
|
|
|
|
|
struct event_trigger_ops *ops,
|
|
|
|
|
struct event_trigger_data *data)
|
|
|
|
|
{
|
|
|
|
|
struct hist_trigger_data *hist_data = data->private_data;
|
2018-01-16 10:51:49 +08:00
|
|
|
struct hist_field *field;
|
|
|
|
|
bool have_var = false;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
unsigned int i;
|
|
|
|
|
|
2016-03-04 02:54:59 +08:00
|
|
|
seq_puts(m, "hist:");
|
|
|
|
|
|
|
|
|
|
if (data->name)
|
|
|
|
|
seq_printf(m, "%s:", data->name);
|
|
|
|
|
|
|
|
|
|
seq_puts(m, "keys=");
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
|
|
|
|
|
for_each_hist_key_field(i, hist_data) {
|
2018-01-16 10:51:49 +08:00
|
|
|
field = hist_data->fields[i];
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
|
|
|
|
|
if (i > hist_data->n_vals)
|
|
|
|
|
seq_puts(m, ",");
|
|
|
|
|
|
2018-01-16 10:51:49 +08:00
|
|
|
if (field->flags & HIST_FIELD_FL_STACKTRACE)
|
2016-03-04 02:54:52 +08:00
|
|
|
seq_puts(m, "stacktrace");
|
|
|
|
|
else
|
2018-01-16 10:51:49 +08:00
|
|
|
hist_field_print(m, field);
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
seq_puts(m, ":vals=");
|
2016-03-04 02:54:43 +08:00
|
|
|
|
|
|
|
|
for_each_hist_val_field(i, hist_data) {
|
2018-01-16 10:51:49 +08:00
|
|
|
field = hist_data->fields[i];
|
|
|
|
|
if (field->flags & HIST_FIELD_FL_VAR) {
|
|
|
|
|
have_var = true;
|
|
|
|
|
continue;
|
|
|
|
|
}
|
|
|
|
|
|
2016-03-04 02:54:43 +08:00
|
|
|
if (i == HITCOUNT_IDX)
|
|
|
|
|
seq_puts(m, "hitcount");
|
|
|
|
|
else {
|
|
|
|
|
seq_puts(m, ",");
|
2018-01-16 10:51:49 +08:00
|
|
|
hist_field_print(m, field);
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if (have_var) {
|
|
|
|
|
unsigned int n = 0;
|
|
|
|
|
|
|
|
|
|
seq_puts(m, ":");
|
|
|
|
|
|
|
|
|
|
for_each_hist_val_field(i, hist_data) {
|
|
|
|
|
field = hist_data->fields[i];
|
|
|
|
|
|
|
|
|
|
if (field->flags & HIST_FIELD_FL_VAR) {
|
|
|
|
|
if (n++)
|
|
|
|
|
seq_puts(m, ",");
|
|
|
|
|
hist_field_print(m, field);
|
|
|
|
|
}
|
2016-03-04 02:54:43 +08:00
|
|
|
}
|
|
|
|
|
}
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
|
|
|
|
|
seq_puts(m, ":sort=");
|
2016-03-04 02:54:45 +08:00
|
|
|
|
|
|
|
|
for (i = 0; i < hist_data->n_sort_keys; i++) {
|
|
|
|
|
struct tracing_map_sort_key *sort_key;
|
2018-01-16 10:51:49 +08:00
|
|
|
unsigned int idx, first_key_idx;
|
|
|
|
|
|
|
|
|
|
/* skip VAR vals */
|
|
|
|
|
first_key_idx = hist_data->n_vals - hist_data->n_vars;
|
2016-03-04 02:54:45 +08:00
|
|
|
|
|
|
|
|
sort_key = &hist_data->sort_keys[i];
|
2018-01-16 10:51:45 +08:00
|
|
|
idx = sort_key->field_idx;
|
|
|
|
|
|
2018-01-16 10:51:50 +08:00
|
|
|
if (WARN_ON(idx >= HIST_FIELDS_MAX))
|
2018-01-16 10:51:45 +08:00
|
|
|
return -EINVAL;
|
2016-03-04 02:54:45 +08:00
|
|
|
|
|
|
|
|
if (i > 0)
|
|
|
|
|
seq_puts(m, ",");
|
|
|
|
|
|
2018-01-16 10:51:45 +08:00
|
|
|
if (idx == HITCOUNT_IDX)
|
2016-03-04 02:54:45 +08:00
|
|
|
seq_puts(m, "hitcount");
|
2018-01-16 10:51:49 +08:00
|
|
|
else {
|
|
|
|
|
if (idx >= first_key_idx)
|
|
|
|
|
idx += hist_data->n_vars;
|
2016-03-04 02:54:45 +08:00
|
|
|
hist_field_print(m, hist_data->fields[idx]);
|
2018-01-16 10:51:49 +08:00
|
|
|
}
|
2016-03-04 02:54:45 +08:00
|
|
|
|
|
|
|
|
if (sort_key->descending)
|
|
|
|
|
seq_puts(m, ".descending");
|
|
|
|
|
}
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
seq_printf(m, ":size=%u", (1 << hist_data->map->map_bits));
|
2018-01-16 10:52:08 +08:00
|
|
|
if (hist_data->enable_timestamps)
|
|
|
|
|
seq_printf(m, ":clock=%s", hist_data->attrs->clock);
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
|
2018-01-16 10:52:00 +08:00
|
|
|
print_actions_spec(m, hist_data);
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
if (data->filter_str)
|
|
|
|
|
seq_printf(m, " if %s", data->filter_str);
|
|
|
|
|
|
2016-03-04 02:54:46 +08:00
|
|
|
if (data->paused)
|
|
|
|
|
seq_puts(m, " [paused]");
|
|
|
|
|
else
|
|
|
|
|
seq_puts(m, " [active]");
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
|
|
|
|
|
seq_putc(m, '\n');
|
|
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
|
2016-03-04 02:54:59 +08:00
|
|
|
static int event_hist_trigger_init(struct event_trigger_ops *ops,
|
|
|
|
|
struct event_trigger_data *data)
|
|
|
|
|
{
|
|
|
|
|
struct hist_trigger_data *hist_data = data->private_data;
|
|
|
|
|
|
|
|
|
|
if (!data->ref && hist_data->attrs->name)
|
|
|
|
|
save_named_trigger(hist_data->attrs->name, data);
|
|
|
|
|
|
|
|
|
|
data->ref++;
|
|
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:51:59 +08:00
|
|
|
static void unregister_field_var_hists(struct hist_trigger_data *hist_data)
|
|
|
|
|
{
|
|
|
|
|
struct trace_event_file *file;
|
|
|
|
|
unsigned int i;
|
|
|
|
|
char *cmd;
|
|
|
|
|
int ret;
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < hist_data->n_field_var_hists; i++) {
|
|
|
|
|
file = hist_data->field_var_hists[i]->hist_data->event_file;
|
|
|
|
|
cmd = hist_data->field_var_hists[i]->cmd;
|
|
|
|
|
ret = event_hist_trigger_func(&trigger_hist_cmd, file,
|
|
|
|
|
"!hist", "hist", cmd);
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
static void event_hist_trigger_free(struct event_trigger_ops *ops,
|
|
|
|
|
struct event_trigger_data *data)
|
|
|
|
|
{
|
|
|
|
|
struct hist_trigger_data *hist_data = data->private_data;
|
|
|
|
|
|
|
|
|
|
if (WARN_ON_ONCE(data->ref <= 0))
|
|
|
|
|
return;
|
|
|
|
|
|
|
|
|
|
data->ref--;
|
|
|
|
|
if (!data->ref) {
|
2016-03-04 02:54:59 +08:00
|
|
|
if (data->name)
|
|
|
|
|
del_named_trigger(data);
|
2018-01-16 10:51:56 +08:00
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
trigger_data_free(data);
|
2018-01-16 10:51:56 +08:00
|
|
|
|
|
|
|
|
remove_hist_vars(hist_data);
|
|
|
|
|
|
tracing: Add support for 'field variables'
Users should be able to directly specify event fields in hist trigger
'actions' rather than being forced to explicitly create a variable for
that purpose.
Add support allowing fields to be used directly in actions, which
essentially does just that - creates 'invisible' variables for each
bare field specified in an action. If a bare field refers to a field
on another (matching) event, it even creates a special histogram for
the purpose (since variables can't be defined on an existing histogram
after histogram creation).
Here's a simple example that demonstrates both. Basically the
onmatch() action creates a list of variables corresponding to the
parameters of the synthetic event to be generated, and then uses those
values to generate the event. So for the wakeup_latency synthetic
event 'call' below the first param, $wakeup_lat, is a variable defined
explicitly on sched_switch, where 'next_pid' is just a normal field on
sched_switch, and prio is a normal field on sched_waking.
Since the mechanism works on variables, those two normal fields just
have 'invisible' variables created internally for them. In the case of
'prio', which is on another event, we actually need to create an
additional hist trigger and define the invisible variable on that, since
once a hist trigger is defined, variables can't be added to it later.
echo 'wakeup_latency u64 lat; pid_t pid; int prio' >>
/sys/kernel/debug/tracing/synthetic_events
echo 'hist:keys=pid:ts0=common_timestamp.usecs >>
/sys/kernel/debug/tracing/events/sched/sched_waking/trigger
echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:
onmatch(sched.sched_waking).wakeup_latency($wakeup_lat,next_pid,prio)
>> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger
Link: http://lkml.kernel.org/r/8e8dcdac1ea180ed7a3689e1caeeccede9dc42b3.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:51:59 +08:00
|
|
|
unregister_field_var_hists(hist_data);
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
destroy_hist_data(hist_data);
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static struct event_trigger_ops event_hist_trigger_ops = {
|
|
|
|
|
.func = event_hist_trigger,
|
|
|
|
|
.print = event_hist_trigger_print,
|
2016-03-04 02:54:59 +08:00
|
|
|
.init = event_hist_trigger_init,
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
.free = event_hist_trigger_free,
|
|
|
|
|
};
|
|
|
|
|
|
2016-03-04 02:54:59 +08:00
|
|
|
static int event_hist_trigger_named_init(struct event_trigger_ops *ops,
|
|
|
|
|
struct event_trigger_data *data)
|
|
|
|
|
{
|
|
|
|
|
data->ref++;
|
|
|
|
|
|
|
|
|
|
save_named_trigger(data->named_data->name, data);
|
|
|
|
|
|
|
|
|
|
event_hist_trigger_init(ops, data->named_data);
|
|
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void event_hist_trigger_named_free(struct event_trigger_ops *ops,
|
|
|
|
|
struct event_trigger_data *data)
|
|
|
|
|
{
|
|
|
|
|
if (WARN_ON_ONCE(data->ref <= 0))
|
|
|
|
|
return;
|
|
|
|
|
|
|
|
|
|
event_hist_trigger_free(ops, data->named_data);
|
|
|
|
|
|
|
|
|
|
data->ref--;
|
|
|
|
|
if (!data->ref) {
|
|
|
|
|
del_named_trigger(data);
|
|
|
|
|
trigger_data_free(data);
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static struct event_trigger_ops event_hist_trigger_named_ops = {
|
|
|
|
|
.func = event_hist_trigger,
|
|
|
|
|
.print = event_hist_trigger_print,
|
|
|
|
|
.init = event_hist_trigger_named_init,
|
|
|
|
|
.free = event_hist_trigger_named_free,
|
|
|
|
|
};
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
static struct event_trigger_ops *event_hist_get_trigger_ops(char *cmd,
|
|
|
|
|
char *param)
|
|
|
|
|
{
|
|
|
|
|
return &event_hist_trigger_ops;
|
|
|
|
|
}
|
|
|
|
|
|
2016-03-04 02:54:47 +08:00
|
|
|
static void hist_clear(struct event_trigger_data *data)
|
|
|
|
|
{
|
|
|
|
|
struct hist_trigger_data *hist_data = data->private_data;
|
|
|
|
|
|
2016-03-04 02:54:59 +08:00
|
|
|
if (data->name)
|
|
|
|
|
pause_named_trigger(data);
|
2016-03-04 02:54:47 +08:00
|
|
|
|
|
|
|
|
synchronize_sched();
|
|
|
|
|
|
|
|
|
|
tracing_map_clear(hist_data->map);
|
|
|
|
|
|
2016-03-04 02:54:59 +08:00
|
|
|
if (data->name)
|
|
|
|
|
unpause_named_trigger(data);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static bool compatible_field(struct ftrace_event_field *field,
|
|
|
|
|
struct ftrace_event_field *test_field)
|
|
|
|
|
{
|
|
|
|
|
if (field == test_field)
|
|
|
|
|
return true;
|
|
|
|
|
if (field == NULL || test_field == NULL)
|
|
|
|
|
return false;
|
|
|
|
|
if (strcmp(field->name, test_field->name) != 0)
|
|
|
|
|
return false;
|
|
|
|
|
if (strcmp(field->type, test_field->type) != 0)
|
|
|
|
|
return false;
|
|
|
|
|
if (field->size != test_field->size)
|
|
|
|
|
return false;
|
|
|
|
|
if (field->is_signed != test_field->is_signed)
|
|
|
|
|
return false;
|
|
|
|
|
|
|
|
|
|
return true;
|
2016-03-04 02:54:47 +08:00
|
|
|
}
|
|
|
|
|
|
2016-03-04 02:54:57 +08:00
|
|
|
static bool hist_trigger_match(struct event_trigger_data *data,
|
2016-03-04 02:54:59 +08:00
|
|
|
struct event_trigger_data *data_test,
|
|
|
|
|
struct event_trigger_data *named_data,
|
|
|
|
|
bool ignore_filter)
|
2016-03-04 02:54:57 +08:00
|
|
|
{
|
|
|
|
|
struct tracing_map_sort_key *sort_key, *sort_key_test;
|
|
|
|
|
struct hist_trigger_data *hist_data, *hist_data_test;
|
|
|
|
|
struct hist_field *key_field, *key_field_test;
|
|
|
|
|
unsigned int i;
|
|
|
|
|
|
2016-03-04 02:54:59 +08:00
|
|
|
if (named_data && (named_data != data_test) &&
|
|
|
|
|
(named_data != data_test->named_data))
|
|
|
|
|
return false;
|
|
|
|
|
|
|
|
|
|
if (!named_data && is_named_trigger(data_test))
|
|
|
|
|
return false;
|
|
|
|
|
|
2016-03-04 02:54:57 +08:00
|
|
|
hist_data = data->private_data;
|
|
|
|
|
hist_data_test = data_test->private_data;
|
|
|
|
|
|
|
|
|
|
if (hist_data->n_vals != hist_data_test->n_vals ||
|
|
|
|
|
hist_data->n_fields != hist_data_test->n_fields ||
|
|
|
|
|
hist_data->n_sort_keys != hist_data_test->n_sort_keys)
|
|
|
|
|
return false;
|
|
|
|
|
|
2016-03-04 02:54:59 +08:00
|
|
|
if (!ignore_filter) {
|
|
|
|
|
if ((data->filter_str && !data_test->filter_str) ||
|
|
|
|
|
(!data->filter_str && data_test->filter_str))
|
|
|
|
|
return false;
|
|
|
|
|
}
|
2016-03-04 02:54:57 +08:00
|
|
|
|
|
|
|
|
for_each_hist_field(i, hist_data) {
|
|
|
|
|
key_field = hist_data->fields[i];
|
|
|
|
|
key_field_test = hist_data_test->fields[i];
|
|
|
|
|
|
|
|
|
|
if (key_field->flags != key_field_test->flags)
|
|
|
|
|
return false;
|
2016-03-04 02:54:59 +08:00
|
|
|
if (!compatible_field(key_field->field, key_field_test->field))
|
2016-03-04 02:54:57 +08:00
|
|
|
return false;
|
|
|
|
|
if (key_field->offset != key_field_test->offset)
|
|
|
|
|
return false;
|
2018-01-16 10:51:45 +08:00
|
|
|
if (key_field->size != key_field_test->size)
|
|
|
|
|
return false;
|
|
|
|
|
if (key_field->is_signed != key_field_test->is_signed)
|
|
|
|
|
return false;
|
2018-01-16 10:51:50 +08:00
|
|
|
if (!!key_field->var.name != !!key_field_test->var.name)
|
|
|
|
|
return false;
|
|
|
|
|
if (key_field->var.name &&
|
|
|
|
|
strcmp(key_field->var.name, key_field_test->var.name) != 0)
|
|
|
|
|
return false;
|
2016-03-04 02:54:57 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < hist_data->n_sort_keys; i++) {
|
|
|
|
|
sort_key = &hist_data->sort_keys[i];
|
|
|
|
|
sort_key_test = &hist_data_test->sort_keys[i];
|
|
|
|
|
|
|
|
|
|
if (sort_key->field_idx != sort_key_test->field_idx ||
|
|
|
|
|
sort_key->descending != sort_key_test->descending)
|
|
|
|
|
return false;
|
|
|
|
|
}
|
|
|
|
|
|
2016-03-04 02:54:59 +08:00
|
|
|
if (!ignore_filter && data->filter_str &&
|
2016-03-04 02:54:57 +08:00
|
|
|
(strcmp(data->filter_str, data_test->filter_str) != 0))
|
|
|
|
|
return false;
|
|
|
|
|
|
|
|
|
|
return true;
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
static int hist_register_trigger(char *glob, struct event_trigger_ops *ops,
|
|
|
|
|
struct event_trigger_data *data,
|
|
|
|
|
struct trace_event_file *file)
|
|
|
|
|
{
|
2016-03-04 02:54:46 +08:00
|
|
|
struct hist_trigger_data *hist_data = data->private_data;
|
2016-03-04 02:54:59 +08:00
|
|
|
struct event_trigger_data *test, *named_data = NULL;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
int ret = 0;
|
|
|
|
|
|
2016-03-04 02:54:59 +08:00
|
|
|
if (hist_data->attrs->name) {
|
|
|
|
|
named_data = find_named_trigger(hist_data->attrs->name);
|
|
|
|
|
if (named_data) {
|
|
|
|
|
if (!hist_trigger_match(data, named_data, named_data,
|
|
|
|
|
true)) {
|
2018-01-16 10:52:05 +08:00
|
|
|
hist_err("Named hist trigger doesn't match existing named trigger (includes variables): ", hist_data->attrs->name);
|
2016-03-04 02:54:59 +08:00
|
|
|
ret = -EINVAL;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if (hist_data->attrs->name && !named_data)
|
|
|
|
|
goto new;
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
list_for_each_entry_rcu(test, &file->triggers, list) {
|
|
|
|
|
if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
|
2016-03-04 02:54:59 +08:00
|
|
|
if (!hist_trigger_match(data, test, named_data, false))
|
2016-03-04 02:54:57 +08:00
|
|
|
continue;
|
2016-03-04 02:54:46 +08:00
|
|
|
if (hist_data->attrs->pause)
|
|
|
|
|
test->paused = true;
|
|
|
|
|
else if (hist_data->attrs->cont)
|
|
|
|
|
test->paused = false;
|
2016-03-04 02:54:47 +08:00
|
|
|
else if (hist_data->attrs->clear)
|
|
|
|
|
hist_clear(test);
|
2018-01-16 10:52:05 +08:00
|
|
|
else {
|
|
|
|
|
hist_err("Hist trigger already exists", NULL);
|
2016-03-04 02:54:46 +08:00
|
|
|
ret = -EEXIST;
|
2018-01-16 10:52:05 +08:00
|
|
|
}
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
}
|
2016-03-04 02:54:59 +08:00
|
|
|
new:
|
2016-03-04 02:54:47 +08:00
|
|
|
if (hist_data->attrs->cont || hist_data->attrs->clear) {
|
2018-01-16 10:52:05 +08:00
|
|
|
hist_err("Can't clear or continue a nonexistent hist trigger", NULL);
|
2016-03-04 02:54:46 +08:00
|
|
|
ret = -ENOENT;
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
2016-06-30 08:56:00 +08:00
|
|
|
if (hist_data->attrs->pause)
|
|
|
|
|
data->paused = true;
|
|
|
|
|
|
2016-03-04 02:54:59 +08:00
|
|
|
if (named_data) {
|
|
|
|
|
data->private_data = named_data->private_data;
|
|
|
|
|
set_named_trigger_data(data, named_data);
|
|
|
|
|
data->ops = &event_hist_trigger_named_ops;
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
if (data->ops->init) {
|
|
|
|
|
ret = data->ops->init(data->ops, data);
|
|
|
|
|
if (ret < 0)
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:52:08 +08:00
|
|
|
if (hist_data->enable_timestamps) {
|
|
|
|
|
char *clock = hist_data->attrs->clock;
|
|
|
|
|
|
|
|
|
|
ret = tracing_set_clock(file->tr, hist_data->attrs->clock);
|
|
|
|
|
if (ret) {
|
|
|
|
|
hist_err("Couldn't set trace_clock: ", clock);
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
|
2018-01-16 10:51:45 +08:00
|
|
|
tracing_set_time_stamp_abs(file->tr, true);
|
2018-01-16 10:52:08 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if (named_data)
|
|
|
|
|
destroy_hist_data(hist_data);
|
|
|
|
|
|
|
|
|
|
ret++;
|
2018-01-16 10:51:56 +08:00
|
|
|
out:
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int hist_trigger_enable(struct event_trigger_data *data,
|
|
|
|
|
struct trace_event_file *file)
|
|
|
|
|
{
|
|
|
|
|
int ret = 0;
|
|
|
|
|
|
|
|
|
|
list_add_tail_rcu(&data->list, &file->triggers);
|
|
|
|
|
|
|
|
|
|
update_cond_flag(file);
|
2018-01-16 10:51:45 +08:00
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
if (trace_event_trigger_enable_disable(file, 1) < 0) {
|
|
|
|
|
list_del_rcu(&data->list);
|
|
|
|
|
update_cond_flag(file);
|
|
|
|
|
ret--;
|
|
|
|
|
}
|
2018-01-16 10:51:56 +08:00
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
return ret;
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:51:58 +08:00
|
|
|
static bool have_hist_trigger_match(struct event_trigger_data *data,
|
|
|
|
|
struct trace_event_file *file)
|
|
|
|
|
{
|
|
|
|
|
struct hist_trigger_data *hist_data = data->private_data;
|
|
|
|
|
struct event_trigger_data *test, *named_data = NULL;
|
|
|
|
|
bool match = false;
|
|
|
|
|
|
|
|
|
|
if (hist_data->attrs->name)
|
|
|
|
|
named_data = find_named_trigger(hist_data->attrs->name);
|
|
|
|
|
|
|
|
|
|
list_for_each_entry_rcu(test, &file->triggers, list) {
|
|
|
|
|
if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
|
|
|
|
|
if (hist_trigger_match(data, test, named_data, false)) {
|
|
|
|
|
match = true;
|
|
|
|
|
break;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return match;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:51:56 +08:00
|
|
|
static bool hist_trigger_check_refs(struct event_trigger_data *data,
|
|
|
|
|
struct trace_event_file *file)
|
|
|
|
|
{
|
|
|
|
|
struct hist_trigger_data *hist_data = data->private_data;
|
|
|
|
|
struct event_trigger_data *test, *named_data = NULL;
|
|
|
|
|
|
|
|
|
|
if (hist_data->attrs->name)
|
|
|
|
|
named_data = find_named_trigger(hist_data->attrs->name);
|
|
|
|
|
|
|
|
|
|
list_for_each_entry_rcu(test, &file->triggers, list) {
|
|
|
|
|
if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
|
|
|
|
|
if (!hist_trigger_match(data, test, named_data, false))
|
|
|
|
|
continue;
|
|
|
|
|
hist_data = test->private_data;
|
|
|
|
|
if (check_var_refs(hist_data))
|
|
|
|
|
return true;
|
|
|
|
|
break;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return false;
|
|
|
|
|
}
|
|
|
|
|
|
2016-03-04 02:54:57 +08:00
|
|
|
static void hist_unregister_trigger(char *glob, struct event_trigger_ops *ops,
|
|
|
|
|
struct event_trigger_data *data,
|
|
|
|
|
struct trace_event_file *file)
|
|
|
|
|
{
|
2016-03-04 02:54:59 +08:00
|
|
|
struct hist_trigger_data *hist_data = data->private_data;
|
|
|
|
|
struct event_trigger_data *test, *named_data = NULL;
|
2016-03-04 02:54:57 +08:00
|
|
|
bool unregistered = false;
|
|
|
|
|
|
2016-03-04 02:54:59 +08:00
|
|
|
if (hist_data->attrs->name)
|
|
|
|
|
named_data = find_named_trigger(hist_data->attrs->name);
|
|
|
|
|
|
2016-03-04 02:54:57 +08:00
|
|
|
list_for_each_entry_rcu(test, &file->triggers, list) {
|
|
|
|
|
if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
|
2016-03-04 02:54:59 +08:00
|
|
|
if (!hist_trigger_match(data, test, named_data, false))
|
2016-03-04 02:54:57 +08:00
|
|
|
continue;
|
|
|
|
|
unregistered = true;
|
|
|
|
|
list_del_rcu(&test->list);
|
|
|
|
|
trace_event_trigger_enable_disable(file, 0);
|
|
|
|
|
update_cond_flag(file);
|
|
|
|
|
break;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if (unregistered && test->ops->free)
|
|
|
|
|
test->ops->free(test->ops, test);
|
2018-01-16 10:51:45 +08:00
|
|
|
|
|
|
|
|
if (hist_data->enable_timestamps) {
|
2018-01-16 10:51:49 +08:00
|
|
|
if (!hist_data->remove || unregistered)
|
2018-01-16 10:51:45 +08:00
|
|
|
tracing_set_time_stamp_abs(file->tr, false);
|
|
|
|
|
}
|
2016-03-04 02:54:57 +08:00
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:51:56 +08:00
|
|
|
static bool hist_file_check_refs(struct trace_event_file *file)
|
|
|
|
|
{
|
|
|
|
|
struct hist_trigger_data *hist_data;
|
|
|
|
|
struct event_trigger_data *test;
|
|
|
|
|
|
|
|
|
|
list_for_each_entry_rcu(test, &file->triggers, list) {
|
|
|
|
|
if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
|
|
|
|
|
hist_data = test->private_data;
|
|
|
|
|
if (check_var_refs(hist_data))
|
|
|
|
|
return true;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return false;
|
|
|
|
|
}
|
|
|
|
|
|
2016-03-04 02:54:57 +08:00
|
|
|
static void hist_unreg_all(struct trace_event_file *file)
|
|
|
|
|
{
|
2016-06-30 08:55:59 +08:00
|
|
|
struct event_trigger_data *test, *n;
|
2018-01-16 10:51:45 +08:00
|
|
|
struct hist_trigger_data *hist_data;
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:51:58 +08:00
|
|
|
struct synth_event *se;
|
|
|
|
|
const char *se_name;
|
2016-03-04 02:54:57 +08:00
|
|
|
|
2018-01-16 10:51:56 +08:00
|
|
|
if (hist_file_check_refs(file))
|
|
|
|
|
return;
|
|
|
|
|
|
2016-06-30 08:55:59 +08:00
|
|
|
list_for_each_entry_safe(test, n, &file->triggers, list) {
|
2016-03-04 02:54:57 +08:00
|
|
|
if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
|
2018-01-16 10:51:45 +08:00
|
|
|
hist_data = test->private_data;
|
2016-03-04 02:54:57 +08:00
|
|
|
list_del_rcu(&test->list);
|
|
|
|
|
trace_event_trigger_enable_disable(file, 0);
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:51:58 +08:00
|
|
|
|
|
|
|
|
mutex_lock(&synth_event_mutex);
|
|
|
|
|
se_name = trace_event_name(file->event_call);
|
|
|
|
|
se = find_synth_event(se_name);
|
|
|
|
|
if (se)
|
|
|
|
|
se->ref--;
|
|
|
|
|
mutex_unlock(&synth_event_mutex);
|
|
|
|
|
|
2016-03-04 02:54:57 +08:00
|
|
|
update_cond_flag(file);
|
2018-01-16 10:51:45 +08:00
|
|
|
if (hist_data->enable_timestamps)
|
|
|
|
|
tracing_set_time_stamp_abs(file->tr, false);
|
2016-03-04 02:54:57 +08:00
|
|
|
if (test->ops->free)
|
|
|
|
|
test->ops->free(test->ops, test);
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
static int event_hist_trigger_func(struct event_command *cmd_ops,
|
|
|
|
|
struct trace_event_file *file,
|
|
|
|
|
char *glob, char *cmd, char *param)
|
|
|
|
|
{
|
|
|
|
|
unsigned int hist_trigger_bits = TRACING_MAP_BITS_DEFAULT;
|
|
|
|
|
struct event_trigger_data *trigger_data;
|
|
|
|
|
struct hist_trigger_attrs *attrs;
|
|
|
|
|
struct event_trigger_ops *trigger_ops;
|
|
|
|
|
struct hist_trigger_data *hist_data;
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:51:58 +08:00
|
|
|
struct synth_event *se;
|
|
|
|
|
const char *se_name;
|
2018-01-16 10:51:49 +08:00
|
|
|
bool remove = false;
|
2018-01-16 10:52:02 +08:00
|
|
|
char *trigger, *p;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
int ret = 0;
|
|
|
|
|
|
2018-01-16 10:52:05 +08:00
|
|
|
if (glob && strlen(glob)) {
|
|
|
|
|
last_cmd_set(param);
|
|
|
|
|
hist_err_clear();
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
if (!param)
|
|
|
|
|
return -EINVAL;
|
|
|
|
|
|
2018-01-16 10:51:49 +08:00
|
|
|
if (glob[0] == '!')
|
|
|
|
|
remove = true;
|
|
|
|
|
|
2018-01-16 10:52:02 +08:00
|
|
|
/*
|
|
|
|
|
* separate the trigger from the filter (k:v [if filter])
|
|
|
|
|
* allowing for whitespace in the trigger
|
|
|
|
|
*/
|
|
|
|
|
p = trigger = param;
|
|
|
|
|
do {
|
|
|
|
|
p = strstr(p, "if");
|
|
|
|
|
if (!p)
|
|
|
|
|
break;
|
|
|
|
|
if (p == param)
|
|
|
|
|
return -EINVAL;
|
|
|
|
|
if (*(p - 1) != ' ' && *(p - 1) != '\t') {
|
|
|
|
|
p++;
|
|
|
|
|
continue;
|
|
|
|
|
}
|
|
|
|
|
if (p >= param + strlen(param) - strlen("if") - 1)
|
|
|
|
|
return -EINVAL;
|
|
|
|
|
if (*(p + strlen("if")) != ' ' && *(p + strlen("if")) != '\t') {
|
|
|
|
|
p++;
|
|
|
|
|
continue;
|
|
|
|
|
}
|
|
|
|
|
break;
|
|
|
|
|
} while (p);
|
|
|
|
|
|
|
|
|
|
if (!p)
|
|
|
|
|
param = NULL;
|
|
|
|
|
else {
|
|
|
|
|
*(p - 1) = '\0';
|
|
|
|
|
param = strstrip(p);
|
|
|
|
|
trigger = strstrip(trigger);
|
|
|
|
|
}
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
|
|
|
|
|
attrs = parse_hist_trigger_attrs(trigger);
|
|
|
|
|
if (IS_ERR(attrs))
|
|
|
|
|
return PTR_ERR(attrs);
|
|
|
|
|
|
|
|
|
|
if (attrs->map_bits)
|
|
|
|
|
hist_trigger_bits = attrs->map_bits;
|
|
|
|
|
|
2018-01-16 10:51:49 +08:00
|
|
|
hist_data = create_hist_data(hist_trigger_bits, attrs, file, remove);
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
if (IS_ERR(hist_data)) {
|
|
|
|
|
destroy_hist_trigger_attrs(attrs);
|
|
|
|
|
return PTR_ERR(hist_data);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
trigger_ops = cmd_ops->get_trigger_ops(cmd, trigger);
|
|
|
|
|
|
|
|
|
|
trigger_data = kzalloc(sizeof(*trigger_data), GFP_KERNEL);
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:51:58 +08:00
|
|
|
if (!trigger_data) {
|
|
|
|
|
ret = -ENOMEM;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
goto out_free;
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:51:58 +08:00
|
|
|
}
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
|
|
|
|
|
trigger_data->count = -1;
|
|
|
|
|
trigger_data->ops = trigger_ops;
|
|
|
|
|
trigger_data->cmd_ops = cmd_ops;
|
|
|
|
|
|
|
|
|
|
INIT_LIST_HEAD(&trigger_data->list);
|
|
|
|
|
RCU_INIT_POINTER(trigger_data->filter, NULL);
|
|
|
|
|
|
|
|
|
|
trigger_data->private_data = hist_data;
|
|
|
|
|
|
2016-03-04 02:54:57 +08:00
|
|
|
/* if param is non-empty, it's supposed to be a filter */
|
|
|
|
|
if (param && cmd_ops->set_filter) {
|
|
|
|
|
ret = cmd_ops->set_filter(param, trigger_data, file);
|
|
|
|
|
if (ret < 0)
|
|
|
|
|
goto out_free;
|
|
|
|
|
}
|
|
|
|
|
|
2018-01-16 10:51:49 +08:00
|
|
|
if (remove) {
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:51:58 +08:00
|
|
|
if (!have_hist_trigger_match(trigger_data, file))
|
|
|
|
|
goto out_free;
|
|
|
|
|
|
2018-01-16 10:51:56 +08:00
|
|
|
if (hist_trigger_check_refs(trigger_data, file)) {
|
|
|
|
|
ret = -EBUSY;
|
|
|
|
|
goto out_free;
|
|
|
|
|
}
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file);
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:51:58 +08:00
|
|
|
|
|
|
|
|
mutex_lock(&synth_event_mutex);
|
|
|
|
|
se_name = trace_event_name(file->event_call);
|
|
|
|
|
se = find_synth_event(se_name);
|
|
|
|
|
if (se)
|
|
|
|
|
se->ref--;
|
|
|
|
|
mutex_unlock(&synth_event_mutex);
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
ret = 0;
|
|
|
|
|
goto out_free;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file);
|
|
|
|
|
/*
|
|
|
|
|
* The above returns on success the # of triggers registered,
|
|
|
|
|
* but if it didn't register any it returns zero. Consider no
|
|
|
|
|
* triggers registered a failure too.
|
|
|
|
|
*/
|
|
|
|
|
if (!ret) {
|
2016-03-04 02:54:47 +08:00
|
|
|
if (!(attrs->pause || attrs->cont || attrs->clear))
|
2016-03-04 02:54:46 +08:00
|
|
|
ret = -ENOENT;
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
goto out_free;
|
|
|
|
|
} else if (ret < 0)
|
|
|
|
|
goto out_free;
|
2018-01-16 10:51:56 +08:00
|
|
|
|
|
|
|
|
if (get_named_trigger_data(trigger_data))
|
|
|
|
|
goto enable;
|
|
|
|
|
|
|
|
|
|
if (has_hist_vars(hist_data))
|
|
|
|
|
save_hist_vars(hist_data);
|
|
|
|
|
|
2018-01-16 10:51:57 +08:00
|
|
|
ret = create_actions(hist_data, file);
|
|
|
|
|
if (ret)
|
|
|
|
|
goto out_unreg;
|
|
|
|
|
|
2018-01-16 10:51:56 +08:00
|
|
|
ret = tracing_map_init(hist_data->map);
|
|
|
|
|
if (ret)
|
|
|
|
|
goto out_unreg;
|
|
|
|
|
enable:
|
|
|
|
|
ret = hist_trigger_enable(trigger_data, file);
|
|
|
|
|
if (ret)
|
|
|
|
|
goto out_unreg;
|
|
|
|
|
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:51:58 +08:00
|
|
|
mutex_lock(&synth_event_mutex);
|
|
|
|
|
se_name = trace_event_name(file->event_call);
|
|
|
|
|
se = find_synth_event(se_name);
|
|
|
|
|
if (se)
|
|
|
|
|
se->ref++;
|
|
|
|
|
mutex_unlock(&synth_event_mutex);
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
/* Just return zero, not the number of registered triggers */
|
|
|
|
|
ret = 0;
|
|
|
|
|
out:
|
2018-01-16 10:52:05 +08:00
|
|
|
if (ret == 0)
|
|
|
|
|
hist_err_clear();
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
return ret;
|
2018-01-16 10:51:56 +08:00
|
|
|
out_unreg:
|
|
|
|
|
cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file);
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
out_free:
|
|
|
|
|
if (cmd_ops->set_filter)
|
|
|
|
|
cmd_ops->set_filter(NULL, trigger_data, NULL);
|
|
|
|
|
|
2018-01-16 10:51:56 +08:00
|
|
|
remove_hist_vars(hist_data);
|
|
|
|
|
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
kfree(trigger_data);
|
|
|
|
|
|
|
|
|
|
destroy_hist_data(hist_data);
|
|
|
|
|
goto out;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static struct event_command trigger_hist_cmd = {
|
|
|
|
|
.name = "hist",
|
|
|
|
|
.trigger_type = ETT_EVENT_HIST,
|
|
|
|
|
.flags = EVENT_CMD_FL_NEEDS_REC,
|
|
|
|
|
.func = event_hist_trigger_func,
|
|
|
|
|
.reg = hist_register_trigger,
|
2016-03-04 02:54:57 +08:00
|
|
|
.unreg = hist_unregister_trigger,
|
|
|
|
|
.unreg_all = hist_unreg_all,
|
tracing: Add 'hist' event trigger command
'hist' triggers allow users to continually aggregate trace events,
which can then be viewed afterwards by simply reading a 'hist' file
containing the aggregation in a human-readable format.
The basic idea is very simple and boils down to a mechanism whereby
trace events, rather than being exhaustively dumped in raw form and
viewed directly, are automatically 'compressed' into meaningful tables
completely defined by the user.
This is done strictly via single-line command-line commands and
without the aid of any kind of programming language or interpreter.
A surprising number of typical use cases can be accomplished by users
via this simple mechanism. In fact, a large number of the tasks that
users typically do using the more complicated script-based tracing
tools, at least during the initial stages of an investigation, can be
accomplished by simply specifying a set of keys and values to be used
in the creation of a hash table.
The Linux kernel trace event subsystem happens to provide an extensive
list of keys and values ready-made for such a purpose in the form of
the event format files associated with each trace event. By simply
consulting the format file for field names of interest and by plugging
them into the hist trigger command, users can create an endless number
of useful aggregations to help with investigating various properties
of the system. See Documentation/trace/events.txt for examples.
hist triggers are implemented on top of the existing event trigger
infrastructure, and as such are consistent with the existing triggers
from a user's perspective as well.
The basic syntax follows the existing trigger syntax. Users start an
aggregation by writing a 'hist' trigger to the event of interest's
trigger file:
# echo hist:keys=xxx [ if filter] > event/trigger
Once a hist trigger has been set up, by default it continually
aggregates every matching event into a hash table using the event key
and a value field named 'hitcount'.
To view the aggregation at any point in time, simply read the 'hist'
file in the same directory as the 'trigger' file:
# cat event/hist
The detailed syntax provides additional options for user control, and
is described exhaustively in Documentation/trace/events.txt and in the
virtual tracing/README file in the tracing subsystem.
Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-03-04 02:54:42 +08:00
|
|
|
.get_trigger_ops = event_hist_get_trigger_ops,
|
|
|
|
|
.set_filter = set_trigger_filter,
|
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
__init int register_trigger_hist_cmd(void)
|
|
|
|
|
{
|
|
|
|
|
int ret;
|
|
|
|
|
|
|
|
|
|
ret = register_event_command(&trigger_hist_cmd);
|
|
|
|
|
WARN_ON(ret < 0);
|
|
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
2016-03-04 02:54:55 +08:00
|
|
|
|
|
|
|
|
static void
|
2018-01-16 10:51:42 +08:00
|
|
|
hist_enable_trigger(struct event_trigger_data *data, void *rec,
|
|
|
|
|
struct ring_buffer_event *event)
|
2016-03-04 02:54:55 +08:00
|
|
|
{
|
|
|
|
|
struct enable_trigger_data *enable_data = data->private_data;
|
|
|
|
|
struct event_trigger_data *test;
|
|
|
|
|
|
|
|
|
|
list_for_each_entry_rcu(test, &enable_data->file->triggers, list) {
|
|
|
|
|
if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
|
|
|
|
|
if (enable_data->enable)
|
|
|
|
|
test->paused = false;
|
|
|
|
|
else
|
|
|
|
|
test->paused = true;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void
|
2018-01-16 10:51:42 +08:00
|
|
|
hist_enable_count_trigger(struct event_trigger_data *data, void *rec,
|
|
|
|
|
struct ring_buffer_event *event)
|
2016-03-04 02:54:55 +08:00
|
|
|
{
|
|
|
|
|
if (!data->count)
|
|
|
|
|
return;
|
|
|
|
|
|
|
|
|
|
if (data->count != -1)
|
|
|
|
|
(data->count)--;
|
|
|
|
|
|
2018-01-16 10:51:42 +08:00
|
|
|
hist_enable_trigger(data, rec, event);
|
2016-03-04 02:54:55 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static struct event_trigger_ops hist_enable_trigger_ops = {
|
|
|
|
|
.func = hist_enable_trigger,
|
|
|
|
|
.print = event_enable_trigger_print,
|
|
|
|
|
.init = event_trigger_init,
|
|
|
|
|
.free = event_enable_trigger_free,
|
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
static struct event_trigger_ops hist_enable_count_trigger_ops = {
|
|
|
|
|
.func = hist_enable_count_trigger,
|
|
|
|
|
.print = event_enable_trigger_print,
|
|
|
|
|
.init = event_trigger_init,
|
|
|
|
|
.free = event_enable_trigger_free,
|
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
static struct event_trigger_ops hist_disable_trigger_ops = {
|
|
|
|
|
.func = hist_enable_trigger,
|
|
|
|
|
.print = event_enable_trigger_print,
|
|
|
|
|
.init = event_trigger_init,
|
|
|
|
|
.free = event_enable_trigger_free,
|
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
static struct event_trigger_ops hist_disable_count_trigger_ops = {
|
|
|
|
|
.func = hist_enable_count_trigger,
|
|
|
|
|
.print = event_enable_trigger_print,
|
|
|
|
|
.init = event_trigger_init,
|
|
|
|
|
.free = event_enable_trigger_free,
|
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
static struct event_trigger_ops *
|
|
|
|
|
hist_enable_get_trigger_ops(char *cmd, char *param)
|
|
|
|
|
{
|
|
|
|
|
struct event_trigger_ops *ops;
|
|
|
|
|
bool enable;
|
|
|
|
|
|
|
|
|
|
enable = (strcmp(cmd, ENABLE_HIST_STR) == 0);
|
|
|
|
|
|
|
|
|
|
if (enable)
|
|
|
|
|
ops = param ? &hist_enable_count_trigger_ops :
|
|
|
|
|
&hist_enable_trigger_ops;
|
|
|
|
|
else
|
|
|
|
|
ops = param ? &hist_disable_count_trigger_ops :
|
|
|
|
|
&hist_disable_trigger_ops;
|
|
|
|
|
|
|
|
|
|
return ops;
|
|
|
|
|
}
|
|
|
|
|
|
2016-03-04 02:54:57 +08:00
|
|
|
static void hist_enable_unreg_all(struct trace_event_file *file)
|
|
|
|
|
{
|
2016-06-30 08:55:59 +08:00
|
|
|
struct event_trigger_data *test, *n;
|
2016-03-04 02:54:57 +08:00
|
|
|
|
2016-06-30 08:55:59 +08:00
|
|
|
list_for_each_entry_safe(test, n, &file->triggers, list) {
|
2016-03-04 02:54:57 +08:00
|
|
|
if (test->cmd_ops->trigger_type == ETT_HIST_ENABLE) {
|
|
|
|
|
list_del_rcu(&test->list);
|
|
|
|
|
update_cond_flag(file);
|
|
|
|
|
trace_event_trigger_enable_disable(file, 0);
|
|
|
|
|
if (test->ops->free)
|
|
|
|
|
test->ops->free(test->ops, test);
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
2016-03-04 02:54:55 +08:00
|
|
|
static struct event_command trigger_hist_enable_cmd = {
|
|
|
|
|
.name = ENABLE_HIST_STR,
|
|
|
|
|
.trigger_type = ETT_HIST_ENABLE,
|
|
|
|
|
.func = event_enable_trigger_func,
|
|
|
|
|
.reg = event_enable_register_trigger,
|
|
|
|
|
.unreg = event_enable_unregister_trigger,
|
2016-03-04 02:54:57 +08:00
|
|
|
.unreg_all = hist_enable_unreg_all,
|
2016-03-04 02:54:55 +08:00
|
|
|
.get_trigger_ops = hist_enable_get_trigger_ops,
|
|
|
|
|
.set_filter = set_trigger_filter,
|
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
static struct event_command trigger_hist_disable_cmd = {
|
|
|
|
|
.name = DISABLE_HIST_STR,
|
|
|
|
|
.trigger_type = ETT_HIST_ENABLE,
|
|
|
|
|
.func = event_enable_trigger_func,
|
|
|
|
|
.reg = event_enable_register_trigger,
|
|
|
|
|
.unreg = event_enable_unregister_trigger,
|
2016-03-04 02:54:57 +08:00
|
|
|
.unreg_all = hist_enable_unreg_all,
|
2016-03-04 02:54:55 +08:00
|
|
|
.get_trigger_ops = hist_enable_get_trigger_ops,
|
|
|
|
|
.set_filter = set_trigger_filter,
|
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
static __init void unregister_trigger_hist_enable_disable_cmds(void)
|
|
|
|
|
{
|
|
|
|
|
unregister_event_command(&trigger_hist_enable_cmd);
|
|
|
|
|
unregister_event_command(&trigger_hist_disable_cmd);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
__init int register_trigger_hist_enable_disable_cmds(void)
|
|
|
|
|
{
|
|
|
|
|
int ret;
|
|
|
|
|
|
|
|
|
|
ret = register_event_command(&trigger_hist_enable_cmd);
|
|
|
|
|
if (WARN_ON(ret < 0))
|
|
|
|
|
return ret;
|
|
|
|
|
ret = register_event_command(&trigger_hist_disable_cmd);
|
|
|
|
|
if (WARN_ON(ret < 0))
|
|
|
|
|
unregister_trigger_hist_enable_disable_cmds();
|
|
|
|
|
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2018-01-16 10:51:58 +08:00
|
|
|
|
|
|
|
|
static __init int trace_events_hist_init(void)
|
|
|
|
|
{
|
|
|
|
|
struct dentry *entry = NULL;
|
|
|
|
|
struct dentry *d_tracer;
|
|
|
|
|
int err = 0;
|
|
|
|
|
|
|
|
|
|
d_tracer = tracing_init_dentry();
|
|
|
|
|
if (IS_ERR(d_tracer)) {
|
|
|
|
|
err = PTR_ERR(d_tracer);
|
|
|
|
|
goto err;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
entry = tracefs_create_file("synthetic_events", 0644, d_tracer,
|
|
|
|
|
NULL, &synth_events_fops);
|
|
|
|
|
if (!entry) {
|
|
|
|
|
err = -ENODEV;
|
|
|
|
|
goto err;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
return err;
|
|
|
|
|
err:
|
|
|
|
|
pr_warn("Could not create tracefs 'synthetic_events' entry\n");
|
|
|
|
|
|
|
|
|
|
return err;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
fs_initcall(trace_events_hist_init);
|
