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perf ftrace: Add support for -a and -C option

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The -a/--all-cpus and -C/--cpu option is for controlling tracing cpus.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: kernel-team@lge.com
Link: http://lkml.kernel.org/r/20170224011251.14946-3-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Namhyung Kim 2017-02-24 10:12:50 +09:00 committed by Arnaldo Carvalho de Melo
parent 4400ac8a9a
commit dc23103278
2 changed files with 74 additions and 0 deletions
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14
tools/perf/Documentation/perf-ftrace.txt
View File

@ -34,6 +34,20 @@ OPTIONS
--pid=::
Trace on existing process id (comma separated list).
-a::
--all-cpus::
Force system-wide collection. Scripts run without a <command>
normally use -a by default, while scripts run with a <command>
normally don't - this option allows the latter to be run in
system-wide mode.
-C::
--cpu=::
Only trace for the list of CPUs provided. Multiple CPUs can
be provided as a comma separated list with no space like: 0,1.
Ranges of CPUs are specified with -: 0-2.
Default is to trace on all online CPUs.
SEE ALSO
--------

60
tools/perf/builtin-ftrace.c
View File

@ -17,6 +17,7 @@
#include <subcmd/parse-options.h>
#include "evlist.h"
#include "target.h"
#include "cpumap.h"
#include "thread_map.h"
#include "util/config.h"
@ -96,6 +97,8 @@ static int append_tracing_file(const char *name, const char *val)
return __write_tracing_file(name, val, true);
}
static int reset_tracing_cpu(void);
static int reset_tracing_files(struct perf_ftrace *ftrace __maybe_unused)
{
if (write_tracing_file("tracing_on", "0") < 0)
@ -107,6 +110,9 @@ static int reset_tracing_files(struct perf_ftrace *ftrace __maybe_unused)
if (write_tracing_file("set_ftrace_pid", " ") < 0)
return -1;
if (reset_tracing_cpu() < 0)
return -1;
return 0;
}
@ -127,6 +133,51 @@ static int set_tracing_pid(struct perf_ftrace *ftrace)
return 0;
}
static int set_tracing_cpumask(struct cpu_map *cpumap)
{
char *cpumask;
size_t mask_size;
int ret;
int last_cpu;
last_cpu = cpu_map__cpu(cpumap, cpumap->nr - 1);
mask_size = (last_cpu + 3) / 4 + 1;
mask_size += last_cpu / 32; /* ',' is needed for every 32th cpus */
cpumask = malloc(mask_size);
if (cpumask == NULL) {
pr_debug("failed to allocate cpu mask\n");
return -1;
}
cpu_map__snprint_mask(cpumap, cpumask, mask_size);
ret = write_tracing_file("tracing_cpumask", cpumask);
free(cpumask);
return ret;
}
static int set_tracing_cpu(struct perf_ftrace *ftrace)
{
struct cpu_map *cpumap = ftrace->evlist->cpus;
if (!target__has_cpu(&ftrace->target))
return 0;
return set_tracing_cpumask(cpumap);
}
static int reset_tracing_cpu(void)
{
struct cpu_map *cpumap = cpu_map__new(NULL);
int ret;
ret = set_tracing_cpumask(cpumap);
cpu_map__put(cpumap);
return ret;
}
static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv)
{
char *trace_file;
@ -163,6 +214,11 @@ static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv)
goto out_reset;
}
if (set_tracing_cpu(ftrace) < 0) {
pr_err("failed to set tracing cpumask\n");
goto out_reset;
}
if (write_tracing_file("current_tracer", ftrace->tracer) < 0) {
pr_err("failed to set current_tracer to %s\n", ftrace->tracer);
goto out_reset;
@ -264,6 +320,10 @@ int cmd_ftrace(int argc, const char **argv, const char *prefix __maybe_unused)
"trace on existing process id"),
OPT_INCR('v', "verbose", &verbose,
"be more verbose"),
OPT_BOOLEAN('a', "all-cpus", &ftrace.target.system_wide,
"system-wide collection from all CPUs"),
OPT_STRING('C', "cpu", &ftrace.target.cpu_list, "cpu",
"list of cpus to monitor"),
OPT_END()
};