Re: [RFC PATCH v1] perf test: Fix perf stat --bpf-counters on hybrid machines

[Namhyung Kim <namhyung@kernel.org>]

On Mon, Mar 23, 2026 at 01:26:11PM -0700, Ian Rogers wrote:
> On Mon, Mar 23, 2026 at 1:24 PM Ian Rogers <irogers@google.com> wrote:
> >
> > Events on hardware PMUs may open on >1 hardware PMU on hybrid
> > machines. Unfortunately multiplexing introduces a scaling issue as
> > reported in:
> > https://lore.kernel.org/lkml/20250716223924.825772-1-irogers@google.com/
> >
> > Switch to using task-clock which as a software event runs on all CPUs
> > and has a single PMU.
> >
> > Signed-off-by: Ian Rogers <irogers@google.com>
> 
> With hindsight, maybe the better thing to do is Namhyung's patch plus
> the "--no-scale" option to `perf stat` to sidestep the scaling issue.
> It'd be great to make this test not "(exclusive)", it shouldn't be
> necessary. You can test for flakiness with the '-r' option to `perf
> test` which takes a repeat count.

I think your fix is simpler and better. :)

Acked-by: Namhyung Kim <namhyung@kernel.org>

Thanks,
Namhyung