diff options
| author | Andrew Vagin | 2012-08-07 16:56:04 +0400 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo | 2012-10-26 11:22:25 -0200 |
| commit | 26a031e136f4f8dc82c64df48cca0eb3b5d3eb4f (patch) | |
| tree | 539d505f3a84f64cc430f87a40205be11c3c93af /tools/perf/Documentation | |
| parent | e558a5bd8b74aff4690a8c55b08a1dc91ef50d7c (diff) | |
perf inject: Merge sched_stat_* and sched_switch events
You may want to know where and how long a task is sleeping. A callchain
may be found in sched_switch and a time slice in stat_iowait, so I add
handler in perf inject for merging this events.
My code saves sched_switch event for each process and when it meets
stat_iowait, it reports the sched_switch event, because this event
contains a correct callchain. By another words it replaces all
stat_iowait events on proper sched_switch events.
I use the next sequence of commands for testing:
perf record -e sched:sched_stat_sleep -e sched:sched_switch \
-e sched:sched_process_exit -g -o ~/perf.data.raw \
~/test-program
perf inject -v -s -i ~/perf.data.raw -o ~/perf.data
perf report --stdio -i ~/perf.data
100.00% foo [kernel.kallsyms] [k] __schedule
|
--- __schedule
schedule
|
|--79.75%-- schedule_hrtimeout_range_clock
| schedule_hrtimeout_range
| poll_schedule_timeout
| do_select
| core_sys_select
| sys_select
| system_call_fastpath
| __select
| __libc_start_main
|
--20.25%-- do_nanosleep
hrtimer_nanosleep
sys_nanosleep
system_call_fastpath
__GI___libc_nanosleep
__libc_start_main
And here is test-program.c:
#include<unistd.h>
#include<time.h>
#include<sys/select.h>
int main()
{
struct timespec ts1;
struct timeval tv1;
int i;
long s;
for (i = 0; i < 10; i++) {
ts1.tv_sec = 0;
ts1.tv_nsec = 10000000;
nanosleep(&ts1, NULL);
tv1.tv_sec = 0;
tv1.tv_usec = 40000;
select(0, NULL, NULL, NULL,&tv1);
}
return 1;
}
Signed-off-by: Andrew Vagin <avagin@openvz.org>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1344344165-369636-4-git-send-email-avagin@openvz.org
[ committer note: Made it use evsel->handler ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/Documentation')
| -rw-r--r-- | tools/perf/Documentation/perf-inject.txt | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/tools/perf/Documentation/perf-inject.txt b/tools/perf/Documentation/perf-inject.txt index 673ef97877fc..a00a34276c54 100644 --- a/tools/perf/Documentation/perf-inject.txt +++ b/tools/perf/Documentation/perf-inject.txt @@ -35,6 +35,11 @@ OPTIONS -o:: --output=:: Output file name. (default: stdout) +-s:: +--sched-stat:: + Merge sched_stat and sched_switch for getting events where and how long + tasks slept. sched_switch contains a callchain where a task slept and + sched_stat contains a timeslice how long a task slept. SEE ALSO -------- |