Re: [PATCH v4 3/3] perf/core: Check sample_type in perf_sample_save_brstack

From: Peter Zijlstra
Date: Wed May 15 2024 - 05:00:26 EST


On Fri, May 10, 2024 at 02:29:58PM -0700, Namhyung Kim wrote:
> On Fri, May 10, 2024 at 12:14 PM Yabin Cui <yabinc@xxxxxxxxxx> wrote:
> >
> > Check sample_type in perf_sample_save_brstack() to prevent
> > saving branch stack data when it isn't required.
> >
> > Suggested-by: Namhyung Kim <namhyung@xxxxxxxxxx>
> > Signed-off-by: Yabin Cui <yabinc@xxxxxxxxxx>
>
> It seems powerpc has the similar bug, then you need this:
>
> Fixes: eb55b455ef9c ("perf/core: Add perf_sample_save_brstack() helper")

Is this really a bug? AFAICT it just does unneeded work, no?