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

Ingo Molnar
2015-05-23T08:22:29Z

* 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