Re: [PATCH] perf test: fix failing test cases on linux-next for s390

[Ian Rogers]

On Fri, Jun 16, 2023 at 6:13 AM Arnaldo Carvalho de Melo
<acme@xxxxxxxxxx> wrote:
>
> Em Fri, Jun 16, 2023 at 10:14:37AM +0200, Thomas Richter escreveu:
> > In linux-next tree the many test cases fail on s390x when running the
> > perf test suite, sometime the perf tool dumps core.
> >
> > Output before:
> >   6.1: Test event parsing                               : FAILED!
> >  10.3: Parsing of PMU event table metrics               : FAILED!
> >  10.4: Parsing of PMU event table metrics with fake PMUs: FAILED!
> >  17: Setup struct perf_event_attr                       : FAILED!
> >  24: Number of exit events of a simple workload         : FAILED!
> >  26: Object code reading                                : FAILED!
> >  28: Use a dummy software event to keep tracking        : FAILED!
> >  35: Track with sched_switch                            : FAILED!
> >  42.3: BPF prologue generation                          : FAILED!
> >  66: Parse and process metrics                          : FAILED!
> >  68: Event expansion for cgroups                        : FAILED!
> >  69.2: Perf time to TSC                                 : FAILED!
> >  74: build id cache operations                          : FAILED!
> >  86: Zstd perf.data compression/decompression           : FAILED!
> >  87: perf record tests                                  : FAILED!
> > 106: Test java symbol                                   : FAILED!
> >
> > The reason for all these failure is a missing PMU. On s390x
> > the PMU is named cpum_cf which is not detected as core PMU.
> > A similar patch was added before, see
> > commit 9bacbced0e32 ("perf list: Add s390 support for detailed PMU event description")
> > which got lost during the recent reworks. Add it again.
> >
> > Output after:
> >  10.2: PMU event map aliases                            : FAILED!
> >  42.3: BPF prologue generation                          : FAILED!
> >
> > Most test cases now work and there is not core dump anymore.
>
> So you're not fixing 'perf test', that is just what detects the problem,
> the part being fixed is the PMU code, so I'm rewriting the patch subject
> to:
>
> [PATCH] perf pmu: Fix core PMU detection on s/390
>
> Have you bisected the problem to the first patch where this problem
> appears?

I suspect:
https://lore.kernel.org/all/20230527072210.2900565-30-irogers@xxxxxxxxxx/
9d6a1df9b2ee ("perf pmus: Allow just core PMU scanning")

Acked-by: Ian Rogers <irogers@xxxxxxxxxx>

Thanks,
Ian

> - Arnaldo
>
> > Signed-off-by: Thomas Richter <tmricht@xxxxxxxxxxxxx>
> > Cc: Ian Rogers <irogers@xxxxxxxxxx>
> > ---
> >  tools/perf/util/pmu.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
> > index fe64ad292d36..6142e4710a2f 100644
> > --- a/tools/perf/util/pmu.c
> > +++ b/tools/perf/util/pmu.c
> > @@ -1419,7 +1419,7 @@ void perf_pmu__del_formats(struct list_head *formats)
> >
> >  bool is_pmu_core(const char *name)
> >  {
> > -     return !strcmp(name, "cpu") || is_sysfs_pmu_core(name);
> > +     return !strcmp(name, "cpu") || !strcmp(name, "cpum_cf") || is_sysfs_pmu_core(name);
> >  }
> >
> >  bool perf_pmu__supports_legacy_cache(const struct perf_pmu *pmu)
> > --
> > 2.39.2
> >
>
> --
>
> - Arnaldo