mirror of
https://github.com/torvalds/linux.git
synced 2024-12-24 11:51:27 +00:00
26a031e136
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>
47 lines
1.1 KiB
Plaintext
47 lines
1.1 KiB
Plaintext
perf-inject(1)
|
|
==============
|
|
|
|
NAME
|
|
----
|
|
perf-inject - Filter to augment the events stream with additional information
|
|
|
|
SYNOPSIS
|
|
--------
|
|
[verse]
|
|
'perf inject <options>'
|
|
|
|
DESCRIPTION
|
|
-----------
|
|
perf-inject reads a perf-record event stream and repipes it to stdout. At any
|
|
point the processing code can inject other events into the event stream - in
|
|
this case build-ids (-b option) are read and injected as needed into the event
|
|
stream.
|
|
|
|
Build-ids are just the first user of perf-inject - potentially anything that
|
|
needs userspace processing to augment the events stream with additional
|
|
information could make use of this facility.
|
|
|
|
OPTIONS
|
|
-------
|
|
-b::
|
|
--build-ids=::
|
|
Inject build-ids into the output stream
|
|
-v::
|
|
--verbose::
|
|
Be more verbose.
|
|
-i::
|
|
--input=::
|
|
Input file name. (default: stdin)
|
|
-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
|
|
--------
|
|
linkperf:perf-record[1], linkperf:perf-report[1], linkperf:perf-archive[1]
|