Re: [PATCH V2] perf-sched: add option to merge like comms to lat output

[Ingo Molnar <mingo@kernel.org>]

* Josef Bacik <jbacik@fb.com> wrote:

> Sometimes when debugging large multi-threaded applications it is helpful to
> collate all of the latency numbers into one bulk record to get an idea of what
> is going on.  This patch does this by merging any entries that belong to the
> same comm into one entry and then spits out those totals.  I've also slightly
> changed the output so you can see how many threads were merged in the
> processing.  Here is the new default output format
> 
>  -----------------------------------------------------------------------------------------------------------------
>   Task                  |   Runtime ms  | Switches | Average delay ms | Maximum delay ms | Maximum delay at       |
>  -----------------------------------------------------------------------------------------------------------------
>   chrome:(23)           |    740.878 ms |     2612 | avg:    0.022 ms | max:    0.845 ms | max at:   7935.254223 s
>   pulseaudio:1523       |     94.440 ms |      597 | avg:    0.027 ms | max:    0.110 ms | max at:   7934.668372 s
>   threaded-ml:6042      |     72.554 ms |      386 | avg:    0.035 ms | max:    1.186 ms | max at:   7935.330911 s
>   Chrome_IOThread:3832  |     52.388 ms |      456 | avg:    0.021 ms | max:    1.365 ms | max at:   7935.330602 s
>   Chrome_ChildIOT:(7)   |     50.694 ms |      743 | avg:    0.021 ms | max:    1.448 ms | max at:   7935.256659 s
>   Compositor:5510       |     30.012 ms |      192 | avg:    0.019 ms | max:    0.131 ms | max at:   7936.636815 s
>   plugin_audio_th:6043  |     24.828 ms |      314 | avg:    0.018 ms | max:    0.143 ms | max at:   7936.205994 s
>   CompositorTileW:(2)   |     14.099 ms |       45 | avg:    0.022 ms | max:    0.153 ms | max at:   7937.521800 s
> 
> the (#) after the task is the number of tasks merged, and then if 
> there were no tasks merged it just shows the pid.  Here is the same 
> trace file with the -p option to print the per-pid latency numbers

Nice!

Acked-by: Ingo Molnar <mingo@kernel.org>

Thanks,

	Ingo