Re: [PATCH 2/2] perf sched timehist: Fix invalid runtime in the idle hist

Arnaldo Carvalho de Melo
2016-12-13T10:32:50Z

Em Tue, Dec 13, 2016 at 05:06:32PM +0900, Namhyung Kim escreveu:
> When --idle-hist option is used, run/wait time and sched delay value
> should be shown for idle task only. But due to internal accounting, a
> last thread has same value of next idle task's and it was shown.
>
> In the below example, firefox after idle task has same run time of
> idle task's.

Same as last message, is this something I can fold into a patch yet in
my perf/core branch?

- Arnaldo

> $ perf sched timehist --idle-hist
> Samples do not have callchains.
> time cpu task name wait time sch delay run time
> [tid/pid] (msec) (msec) (msec)
> --------------- ------ -------------------- --------- --------- ---------
> 197731.754335 [0002] firefox[17773/17739] 0.000 0.000 0.000
> 197731.754486 [0001] sleep[27470] 0.000 0.000 0.000
> 197731.754903 [0002] <idle> 0.047 0.000 0.567
> 197731.754981 [0002] firefox[17773/17739] 0.000 0.000 0.567
> 197731.755922 [0002] <idle> 0.078 0.000 0.941
> 197731.755994 [0002] firefox[17773/17739] 0.000 0.000 0.941
> <SNIP>
>
> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
> ---
> tools/perf/builtin-sched.c | 9 +++++++++
> 1 file changed, 9 insertions(+)
>
> diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c
> index 405a91d0515f..64a0959bccd7 100644
> --- a/tools/perf/builtin-sched.c
> +++ b/tools/perf/builtin-sched.c
> @@ -2439,6 +2439,15 @@ static int timehist_sched_change_event(struct perf_tool *tool,
> goto out;
>
> timehist_update_runtime_stats(last_tr, t, tprev);
> + /*
> + * remove delta time of last thread as it's not updated
> + * and otherwise it will show an invalid value next
> + * time. we only care total run time and run stat.
> + */
> + last_tr->dt_run = 0;
> + last_tr->dt_wait = 0;
> + last_tr->dt_delay = 0;
> +
> if (itr->cursor.nr)
> callchain_append(&itr->callchain, &itr->cursor,
> t - tprev);
> --
> 2.10.2