Re: [PATCH v2] perf test stat: Avoid hybrid assumption when virtualized

From: Arnaldo Carvalho de Melo
Date: Mon Jan 13 2025 - 10:37:31 EST


On Thu, Dec 12, 2024 at 07:31:04PM -0800, Ian Rogers wrote:
> On Thu, Dec 12, 2024 at 5:39 PM Namhyung Kim <namhyung@xxxxxxxxxx> wrote:
> > On Thu, Dec 12, 2024 at 09:33:54AM -0800, Ian Rogers wrote:
> > > The cycles event will fallback to task-clock in the hybrid test when
> > > running virtualized. Change the test to not fail for this.

> > > Fixes: a6b8bb2addd0 ("perf test: Add a test for default perf stat command")

> > I cannot find this commit.

> Sorry, should have been:
> Fixes: 65d11821910b ("perf test: Add a test for default perf stat command")

Thanks, applied to perf-tools-next, there was a minimal fuzz but I fixed
it up:

⬢ [acme@toolbox perf-tools-next]$ patch -p1 < ./v2_20241212_irogers_perf_test_stat_avoid_hybrid_assumption_when_virtualized.mbx
patching file tools/perf/tests/shell/stat.sh
Hunk #1 succeeded at 187 with fuzz 2 (offset 24 lines).

- Arnaldo

> Thanks,
> Ian
>
> > > Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
> >
> > Other than that,
> >
> > Acked-by: Namhyung Kim <namhyung@xxxxxxxxxx>
> >
> > Thanks,
> > Namhyung
> >
> > > ---
> > > tools/perf/tests/shell/stat.sh | 6 +++++-
> > > 1 file changed, 5 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/tools/perf/tests/shell/stat.sh b/tools/perf/tests/shell/stat.sh
> > > index 5a2ca2bcf94d..da42427bb077 100755
> > > --- a/tools/perf/tests/shell/stat.sh
> > > +++ b/tools/perf/tests/shell/stat.sh
> > > @@ -163,7 +163,11 @@ test_hybrid() {
> > > # Run default Perf stat
> > > cycles_events=$(perf stat -- true 2>&1 | grep -E "/cycles/| cycles " | wc -l)
> > >
> > > - if [ "$pmus" -ne "$cycles_events" ]
> > > + # The expectation is that default output will have a cycles events on each
> > > + # hybrid PMU. In situations with no cycles PMU events, like virtualized, this
> > > + # can fall back to task-clock and so the end count may be 0. Fail if neither
> > > + # condition holds.
> > > + if [ "$pmus" -ne "$cycles_events" ] && [ "0" -ne "$cycles_events" ]
> > > then
> > > echo "hybrid test [Found $pmus PMUs but $cycles_events cycles events. Failed]"
> > > err=1
> > > --
> > > 2.47.1.613.gc27f4b7a9f-goog
> > >