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

[Thomas Richter <tmricht@linux.ibm.com>]

On 6/16/23 15:13, Arnaldo Carvalho de Melo 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?
> 
> - Arnaldo

Thanks for picking this patch, I noticed it is already in linux-next tree.

No I did not do the bisect. That first patch info came from Ian Rogers.

>  
>> Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
>> Cc: Ian Rogers <irogers@google.com>
>> ---
>>  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
>>
> 

-- 
Thomas Richter, Dept 3303, IBM s390 Linux Development, Boeblingen, Germany
--
Vorsitzender des Aufsichtsrats: Gregor Pillen
Geschäftsführung: David Faller
Sitz der Gesellschaft: Böblingen / Registergericht: Amtsgericht Stuttgart, HRB 243294