Re: [PATCH] perf test: Fix parse-events tests to skip parametrized events

[Athira Rajeev <atrajeev@linux.vnet.ibm.com>]

> On 18-Aug-2023, at 12:07 AM, Ian Rogers <irogers@google.com> wrote:
> 
> On Sun, Aug 6, 2023 at 9:50 PM Athira Rajeev
> <atrajeev@linux.vnet.ibm.com> wrote:
>> 
>> Testcase "Parsing of all PMU events from sysfs" parse events for
>> all PMUs, and not just cpu. In case of powerpc, the PowerVM
>> environment supports events from hv_24x7 and hv_gpci PMU which
>> is of example format like below:
>> 
>> - hv_24x7/CPM_ADJUNCT_INST,domain=?,core=?/
>> - hv_gpci/event,partition_id=?/
>> 
>> The value for "?" needs to be filled in depending on system
>> configuration. It is better to skip these parametrized events
>> in this test as it is done in:
>> 'commit b50d691e50e6 ("perf test: Fix "all PMU test" to skip
>> parametrized events")' which handled a simialr instance with
>> "all PMU test".
> 
> I'd say this is different, the "?" is really ugly. On other
> architectures the problem is solved by having >1 PMU, domain and core
> can be meta-data associated with the PMU. If we want to aggregate
> based on domain and core in the perf tool, it will need a different
> way of solving the problem for Power. Skipping the test is just
> pushing this problem down the road.

Hi Ian

Thanks for the comments. We will check on this for powerpc.
> 
>> Fix parse-events test to skip parametrized events since
>> it needs proper setup of the parameters.
>> 
>> Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
>> ---
>> tools/perf/tests/parse-events.c | 32 ++++++++++++++++++++++++++++++++
>> 1 file changed, 32 insertions(+)
>> 
>> diff --git a/tools/perf/tests/parse-events.c b/tools/perf/tests/parse-events.c
>> index b2f82847e4c3..605373c7d005 100644
>> --- a/tools/perf/tests/parse-events.c
>> +++ b/tools/perf/tests/parse-events.c
>> @@ -2504,7 +2504,11 @@ static int test__pmu_events(struct test_suite *test __maybe_unused, int subtest
>>        while ((pmu = perf_pmus__scan(pmu)) != NULL) {
>>                struct stat st;
>>                char path[PATH_MAX];
>> +               char pmu_event[PATH_MAX + 256];
> 
> By definition paths can't be longer than PATH_MAX.
Yeah, my bad. Will fix this.

> 
>> +               char *buf = NULL;
>> +               FILE *file;
>>                struct dirent *ent;
>> +               size_t len = 0;
>>                DIR *dir;
>>                int err;
>> 
>> @@ -2528,11 +2532,39 @@ static int test__pmu_events(struct test_suite *test __maybe_unused, int subtest
>>                        struct evlist_test e = { .name = NULL, };
>>                        char name[2 * NAME_MAX + 1 + 12 + 3];
>>                        int test_ret;
>> +                       int skip = 0;
> 
> Prefer a boolean. Prefer is_event_parameterized over skip to make
> variable name more intention revealing.
Sure
> 
>> 
>>                        /* Names containing . are special and cannot be used directly */
>>                        if (strchr(ent->d_name, '.'))
>>                                continue;
>> 
>> +                       /* exclude parametrized ones (name contains '?') */
>> +                       snprintf(pmu_event, PATH_MAX + 256, "%s%s", path, ent->d_name);
> 
> Use sizeof(pmu_event) rather than "PATH_MAX + 256".

Will send V2 with these changes
> 
> Thanks,
> Ian
> 
>> +                       file = fopen(pmu_event, "r");
>> +                       if (!file) {
>> +                               pr_debug("can't open pmu event file for '%s'\n", ent->d_name);
>> +                               ret = combine_test_results(ret, TEST_FAIL);
>> +                               continue;
>> +                       }
>> +
>> +                       if (getline(&buf, &len, file) < 0) {
>> +                               pr_debug(" pmu event: %s is a null event\n", ent->d_name);
>> +                               ret = combine_test_results(ret, TEST_FAIL);
>> +                               continue;
>> +                       }
>> +
>> +                       if (strchr(buf, '?'))
>> +                               skip = 1;
>> +
>> +                       free(buf);
>> +                       buf = NULL;
>> +                       fclose(file);
>> +
>> +                       if (skip == 1) {
>> +                               pr_debug("skipping parametrized PMU event: %s which contains ?\n", pmu_event);
>> +                               continue;
>> +                       }
>> +
>>                        snprintf(name, sizeof(name), "%s/event=%s/u", pmu->name, ent->d_name);
>> 
>>                        e.name  = name;
>> --
>> 2.31.1