Re: [PATCH 02/19] perf tools: Use pmu info in evsel__is_hybrid()

From: Ian Rogers
Date: Mon Oct 10 2022 - 18:32:26 EST


On Sun, Oct 9, 2022 at 10:36 PM Namhyung Kim <namhyung@xxxxxxxxxx> wrote:
>
> If evsel has pmu, it can use pmu->is_hybrid directly.
>
> Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
> ---
> tools/perf/util/evsel.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
> index 196f8e4859d7..a6ea91c72659 100644
> --- a/tools/perf/util/evsel.c
> +++ b/tools/perf/util/evsel.c
> @@ -3132,6 +3132,9 @@ void evsel__zero_per_pkg(struct evsel *evsel)
>
> bool evsel__is_hybrid(struct evsel *evsel)
> {
> + if (evsel->pmu)
> + return evsel->pmu->is_hybrid;
> +
> return evsel->pmu_name && perf_pmu__is_hybrid(evsel->pmu_name);

Wow, there's so much duplicated state. Why do evsels have a pmu_name
and a pmu? Why not just pmu->name? I feel always having a pmu would be
cleanest here. That said what does evsel__is_hybrid even mean? Does it
mean this event is on a PMU normally called cpu and called cpu_core
and cpu_atom on hybrid systems? And of course there are no comments to
explain what this little mystery could be. Anyway, that's not a fault
of this change, and probably later changes will go someway toward
cleaning this up. It was a shame the code wasn't cleaner in the first
place.

Acked-by: Ian Rogers

Thanks,
Ian

> }
>
> --
> 2.38.0.rc1.362.ged0d419d3c-goog
>