From: Victor Jimenez <victor.javier@bsc.es>
To: linux-perf-users@vger.kernel.org
Subject: Problem when profiling a process' running/sleeping/waiting time
Date: Wed, 09 Jan 2013 11:56:32 +0100 [thread overview]
Message-ID: <50ED4CE0.7050201@bsc.es> (raw)
I am trying to profile a process in terms of running, sleeping and
waiting time. I am using kernel 3.6.6 running on an IBM POWER7 machine.
Initially, I decided to use a toy example where I would expect that the
process remains in running state most of the time. This is the code for
such a simple example:
int main() {
for (int i = 0; i < 1000000; i++)
for (int j = 0; j < 1000; j++);
}
I am using the following command line for reading kernel stats:
perf stat -e
"sched:sched_stat_runtime,sched:sched_stat_sleep,sched:sched_stat_wait, \
sched:sched_stat_iowait,sched:sched_stat_blocked" ./test
And these are the results that I obtain:
Performance counter stats for './test':
12,077,957,756 sched:sched_stat_runtime
169,892,740,990 sched:sched_stat_sleep
5,816,784 sched:sched_stat_wait
0 sched:sched_stat_iowait
0 sched:sched_stat_blocked
12.084706279 seconds time elapsed
I cannot really understand why the counter for sched_stat_sleep is so
high (even higher than sched_stat_runtime), especially for such a
CPU-bound workload.
Am I missing anything, or there could be a problem with sched_stat_sleep
counter?
Thank you,
Victor
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next reply other threads:[~2013-01-09 11:06 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-01-09 10:56 Victor Jimenez [this message]
2013-06-17 7:20 ` Problem when profiling a process' running/sleeping/waiting time Michael Ellerman
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