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linux-next/tools/perf/Documentation/perf-sched.txt

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perf-sched(1)
==============
NAME
----
perf-sched - Tool to trace/measure scheduler properties (latencies)
SYNOPSIS
--------
[verse]
'perf sched' {record|latency|map|replay|script|timehist}
DESCRIPTION
-----------
There are several variants of 'perf sched':
'perf sched record <command>' to record the scheduling events
of an arbitrary workload.
'perf sched latency' to report the per task scheduling latencies
and other scheduling properties of the workload.
'perf sched script' to see a detailed trace of the workload that
was recorded (aliased to 'perf script' for now).
'perf sched replay' to simulate the workload that was recorded
via perf sched record. (this is done by starting up mockup threads
that mimic the workload based on the events in the trace. These
threads can then replay the timings (CPU runtime and sleep patterns)
of the workload as it occurred when it was recorded - and can repeat
it a number of times, measuring its performance.)
'perf sched map' to print a textual context-switching outline of
workload captured via perf sched record. Columns stand for
individual CPUs, and the two-letter shortcuts stand for tasks that
are running on a CPU. A '*' denotes the CPU that had the event, and
a dot signals an idle CPU.
'perf sched timehist' provides an analysis of scheduling events.
Example usage:
perf sched record -- sleep 1
perf sched timehist
By default it shows the individual schedule events, including the wait
time (time between sched-out and next sched-in events for the task), the
task scheduling delay (time between wakeup and actually running) and run
time for the task:
time cpu task name wait time sch delay run time
[tid/pid] (msec) (msec) (msec)
-------------- ------ -------------------- --------- --------- ---------
79371.874569 [0011] gcc[31949] 0.014 0.000 1.148
79371.874591 [0010] gcc[31951] 0.000 0.000 0.024
79371.874603 [0010] migration/10[59] 3.350 0.004 0.011
79371.874604 [0011] <idle> 1.148 0.000 0.035
79371.874723 [0005] <idle> 0.016 0.000 1.383
79371.874746 [0005] gcc[31949] 0.153 0.078 0.022
...
Times are in msec.usec.
OPTIONS
-------
-i::
--input=<file>::
Input file name. (default: perf.data unless stdin is a fifo)
-v::
--verbose::
Be more verbose. (show symbol address, etc)
-D::
--dump-raw-trace=::
Display verbose dump of the sched data.
OPTIONS for 'perf sched map'
----------------------------
--compact::
Show only CPUs with activity. Helps visualizing on high core
count systems.
--cpus::
Show just entries with activities for the given CPUs.
--color-cpus::
Highlight the given cpus.
--color-pids::
Highlight the given pids.
OPTIONS for 'perf sched timehist'
---------------------------------
-k::
--vmlinux=<file>::
vmlinux pathname
--kallsyms=<file>::
kallsyms pathname
perf sched timehist: Add call graph options If callchains were recorded they are appended to the line with a default stack depth of 5: 1.874569 [0011] gcc[31949] 0.014 0.000 1.148 wait_for_completion_killable <- do_fork <- sys_vfork <- stub_vfork <- __vfork 1.874591 [0010] gcc[31951] 0.000 0.000 0.024 __cond_resched <- _cond_resched <- wait_for_completion <- stop_one_cpu <- sched_exec 1.874603 [0010] migration/10[59] 3.350 0.004 0.011 smpboot_thread_fn <- kthread <- ret_from_fork 1.874604 [0011] <idle> 1.148 0.000 0.035 cpu_startup_entry <- start_secondary 1.874723 [0005] <idle> 0.016 0.000 1.383 cpu_startup_entry <- start_secondary 1.874746 [0005] gcc[31949] 0.153 0.078 0.022 do_wait sys_wait4 <- system_call_fastpath <- __GI___waitpid --no-call-graph can be used to not show the callchains. --max-stack is used to control the number of frames shown (default of 5). -x/--excl options can be used to collapse redundant callchains to get more relevant data on screen. Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: Namhyung Kim <namhyung@kernel.org> Acked-by: Ingo Molnar <mingo@kernel.org> Acked-by: Jiri Olsa <jolsa@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/r/20161116060634.28477-7-namhyung@kernel.org [ Add documentation based on above commit message ] Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-11-16 14:06:32 +08:00
-g::
--no-call-graph::
Do not display call chains if present.
--max-stack::
Maximum number of functions to display in backtrace, default 5.
-p=::
--pid=::
Only show events for given process ID (comma separated list).
-t=::
--tid=::
Only show events for given thread ID (comma separated list).
-s::
--summary::
Show only a summary of scheduling by thread with min, max, and average
run times (in sec) and relative stddev.
-S::
--with-summary::
Show all scheduling events followed by a summary by thread with min,
max, and average run times (in sec) and relative stddev.
--symfs=<directory>::
Look for files with symbols relative to this directory.
-V::
--cpu-visual::
Show visual aid for sched switches by CPU: 'i' marks idle time,
's' are scheduler events.
-w::
--wakeups::
Show wakeup events.
-M::
--migrations::
Show migration events.
-n::
--next::
Show next task.
perf sched timehist: Add -I/--idle-hist option The --idle-hist option is to analyze system idle state so which process makes cpu to go idle. If this option is specified, non-idle events will be skipped and processes switching to/from idle will be shown. This option is mostly useful when used with --summary(-only) option. In the idle-time summary view, idle time is accounted to previous thread which is run before idle task. The example output looks like following: Idle-time summary comm parent sched-out idle-time min-idle avg-idle max-idle stddev migrations (count) (msec) (msec) (msec) (msec) % -------------------------------------------------------------------------------------------- rcu_preempt[7] 2 95 550.872 0.011 5.798 23.146 7.63 0 migration/1[16] 2 1 15.558 15.558 15.558 15.558 0.00 0 khugepaged[39] 2 1 3.062 3.062 3.062 3.062 0.00 0 kworker/0:1H[124] 2 2 4.728 0.611 2.364 4.116 74.12 0 systemd-journal[167] 1 1 4.510 4.510 4.510 4.510 0.00 0 kworker/u16:3[558] 2 13 74.737 0.080 5.749 12.960 21.96 0 irq/34-iwlwifi[628] 2 21 118.403 0.032 5.638 23.990 24.00 0 kworker/u17:0[673] 2 1 3.523 3.523 3.523 3.523 0.00 0 dbus-daemon[722] 1 1 6.743 6.743 6.743 6.743 0.00 0 ifplugd[741] 1 1 58.826 58.826 58.826 58.826 0.00 0 wpa_supplicant[1490] 1 1 13.302 13.302 13.302 13.302 0.00 0 wpa_actiond[1492] 1 2 4.064 0.168 2.032 3.896 91.72 0 dockerd[1500] 1 1 0.055 0.055 0.055 0.055 0.00 0 ... Signed-off-by: Namhyung Kim <namhyung@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Acked-by: David Ahern <dsahern@gmail.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20161208144755.16673-6-namhyung@kernel.org Link: http://lkml.kernel.org/r/20161213080632.19099-2-namhyung@kernel.org [ Merged fix sent by Namhyumg, as posted in the second Link: tag ] Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-12-08 22:47:54 +08:00
-I::
--idle-hist::
Show idle-related events only.
perf sched timehist: Add option to specify time window of interest Add option to allow user to control analysis window. e.g., collect data for time window and analyze a segment of interest within that window. Committer notes: Testing it: # perf sched record -a usleep 1 [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 1.593 MB perf.data (25 samples) ] # # perf sched timehist | head -18 Samples do not have callchains. time cpu task name wait time sch delay run time [tid/pid] (msec) (msec) (msec) ------------- ------ --------------- --------- --------- -------- 19818.635579 [0002] <idle> 0.000 0.000 0.000 19818.635613 [0000] perf[9116] 0.000 0.000 0.000 19818.635676 [0000] <idle> 0.000 0.000 0.063 19818.635678 [0000] rcuos/2[29] 0.000 0.002 0.001 19818.635696 [0002] perf[9117] 0.000 0.004 0.116 19818.635702 [0000] <idle> 0.001 0.000 0.024 19818.635709 [0002] migration/2[25] 0.000 0.003 0.012 19818.636263 [0000] usleep[9117] 0.005 0.000 0.560 19818.636316 [0000] <idle> 0.560 0.000 0.053 19818.636358 [0002] <idle> 0.129 0.000 0.649 19818.636358 [0000] usleep[9117] 0.053 0.002 0.042 # # perf sched timehist --time 19818.635696, Samples do not have callchains. time cpu task name wait time sch delay run time [tid/pid] (msec) (msec) (msec) ------------- ------ --------------- -------- --------- --------- 19818.635696 [0002] perf[9117] 0.000 0.120 0.000 19818.635702 [0000] <idle> 0.019 0.000 0.006 19818.635709 [0002] migration/2[25] 0.000 0.003 0.012 19818.636263 [0000] usleep[9117] 0.005 0.000 0.560 19818.636316 [0000] <idle> 0.560 0.000 0.053 19818.636358 [0002] <idle> 0.129 0.000 0.649 19818.636358 [0000] usleep[9117] 0.053 0.002 0.042 # # perf sched timehist --time 19818.635696,19818.635709 Samples do not have callchains. time cpu task name wait time sch delay run time [tid/pid] (msec) (msec) (msec) ------------- ------ --------------- --------- --------- --------- 19818.635696 [0002] perf[9117] 0.000 0.120 0.000 19818.635702 [0000] <idle> 0.019 0.000 0.006 19818.635709 [0002] migration/2[25] 0.000 0.003 0.012 19818.635709 [0000] usleep[9117] 0.005 0.000 0.006 # Signed-off-by: David Ahern <dsahern@gmail.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1480439746-42695-5-git-send-email-dsahern@gmail.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-11-30 01:15:44 +08:00
--time::
Only analyze samples within given time window: <start>,<stop>. Times
have the format seconds.microseconds. If start is not given (i.e., time
string is ',x.y') then analysis starts at the beginning of the file. If
stop time is not given (i.e, time string is 'x.y,') then analysis goes
to end of file.
--state::
Show task state when it switched out.
perf sched timehist: Add option to specify time window of interest Add option to allow user to control analysis window. e.g., collect data for time window and analyze a segment of interest within that window. Committer notes: Testing it: # perf sched record -a usleep 1 [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 1.593 MB perf.data (25 samples) ] # # perf sched timehist | head -18 Samples do not have callchains. time cpu task name wait time sch delay run time [tid/pid] (msec) (msec) (msec) ------------- ------ --------------- --------- --------- -------- 19818.635579 [0002] <idle> 0.000 0.000 0.000 19818.635613 [0000] perf[9116] 0.000 0.000 0.000 19818.635676 [0000] <idle> 0.000 0.000 0.063 19818.635678 [0000] rcuos/2[29] 0.000 0.002 0.001 19818.635696 [0002] perf[9117] 0.000 0.004 0.116 19818.635702 [0000] <idle> 0.001 0.000 0.024 19818.635709 [0002] migration/2[25] 0.000 0.003 0.012 19818.636263 [0000] usleep[9117] 0.005 0.000 0.560 19818.636316 [0000] <idle> 0.560 0.000 0.053 19818.636358 [0002] <idle> 0.129 0.000 0.649 19818.636358 [0000] usleep[9117] 0.053 0.002 0.042 # # perf sched timehist --time 19818.635696, Samples do not have callchains. time cpu task name wait time sch delay run time [tid/pid] (msec) (msec) (msec) ------------- ------ --------------- -------- --------- --------- 19818.635696 [0002] perf[9117] 0.000 0.120 0.000 19818.635702 [0000] <idle> 0.019 0.000 0.006 19818.635709 [0002] migration/2[25] 0.000 0.003 0.012 19818.636263 [0000] usleep[9117] 0.005 0.000 0.560 19818.636316 [0000] <idle> 0.560 0.000 0.053 19818.636358 [0002] <idle> 0.129 0.000 0.649 19818.636358 [0000] usleep[9117] 0.053 0.002 0.042 # # perf sched timehist --time 19818.635696,19818.635709 Samples do not have callchains. time cpu task name wait time sch delay run time [tid/pid] (msec) (msec) (msec) ------------- ------ --------------- --------- --------- --------- 19818.635696 [0002] perf[9117] 0.000 0.120 0.000 19818.635702 [0000] <idle> 0.019 0.000 0.006 19818.635709 [0002] migration/2[25] 0.000 0.003 0.012 19818.635709 [0000] usleep[9117] 0.005 0.000 0.006 # Signed-off-by: David Ahern <dsahern@gmail.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1480439746-42695-5-git-send-email-dsahern@gmail.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-11-30 01:15:44 +08:00
SEE ALSO
--------
linkperf:perf-record[1]