linux-kernel - Re: [PATCH v7 1/8] perf pmu: "Compat" supports matching multiple identifiers

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Message-ID: <8f319bc9-8740-627e-09c7-934c30a053bc@linux.alibaba.com>
Date:   Fri, 25 Aug 2023 14:12:25 +0800
From:   Jing Zhang <renyu.zj@...ux.alibaba.com>
To:     Ian Rogers <irogers@...gle.com>
Cc:     John Garry <john.g.garry@...cle.com>,
        Will Deacon <will@...nel.org>,
        James Clark <james.clark@....com>,
        Arnaldo Carvalho de Melo <acme@...nel.org>,
        Mark Rutland <mark.rutland@....com>,
        Mike Leach <mike.leach@...aro.org>,
        Leo Yan <leo.yan@...aro.org>,
        Namhyung Kim <namhyung@...nel.org>,
        Peter Zijlstra <peterz@...radead.org>,
        Ingo Molnar <mingo@...hat.com>,
        Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
        Jiri Olsa <jolsa@...nel.org>,
        Adrian Hunter <adrian.hunter@...el.com>,
        linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        linux-perf-users@...r.kernel.org, linux-doc@...r.kernel.org,
        Zhuo Song <zhuo.song@...ux.alibaba.com>,
        Shuai Xue <xueshuai@...ux.alibaba.com>
Subject: Re: [PATCH v7 1/8] perf pmu: "Compat" supports matching multiple
 identifiers



在 2023/8/25 下午12:11, Ian Rogers 写道:
> On Mon, Aug 21, 2023 at 1:36 AM Jing Zhang <renyu.zj@...ux.alibaba.com> wrote:
>>
>> The jevent "Compat" is used for uncore PMU alias or metric definitions.
>>
>> The same PMU driver has different PMU identifiers due to different
>> hardware versions and types, but they may have some common PMU event.
>> Since a Compat value can only match one identifier, when adding the
>> same event alias to PMUs with different identifiers, each identifier
>> needs to be defined once, which is not streamlined enough.
>>
>> So let "Compat" supports matching multiple identifiers for uncore PMU
>> alias. For example, the Compat value {43401;436*} can match the PMU
>> identifier "43401", that is, CMN600_r0p0, and the PMU identifier with
>> the prefix "436", that is, all CMN650, where "*" is a wildcard.
>> Tokens in Unit field are delimited by ';' with no spaces.
>>
>> Signed-off-by: Jing Zhang <renyu.zj@...ux.alibaba.com>
>> Reviewed-by: John Garry <john.g.garry@...cle.com>
>> ---
>>  tools/perf/util/pmu.c | 33 +++++++++++++++++++++++++++++++--
>>  tools/perf/util/pmu.h |  1 +
>>  2 files changed, 32 insertions(+), 2 deletions(-)
>>
>> diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
>> index ad209c8..6402423 100644
>> --- a/tools/perf/util/pmu.c
>> +++ b/tools/perf/util/pmu.c
>> @@ -776,6 +776,35 @@ static bool pmu_uncore_alias_match(const char *pmu_name, const char *name)
>>         return res;
>>  }
>>
>> +bool pmu_uncore_identifier_match(const char *id, const char *compat)
> 
> static?
> 

This function needs to be called in utils/metricgroup.c, so it cannot be static.

>> +{
>> +       char *tmp = NULL, *tok, *str;
>> +       bool res;
> 
> Initialize to false to avoid the goto.
> 

ok，no problem.

>> +       int n;
> 
> Move into the scope of the for loop, to reduce the scope.
> 

ok

>> +
>> +       /*
>> +        * The strdup() call is necessary here because "compat" is a const str*
>> +        * type and cannot be used as an argument to strtok_r().
>> +        */
>> +       str = strdup(compat);
>> +       if (!str)
>> +               return false;
>> +
>> +       tok = strtok_r(str, ";", &tmp);
>> +       for (; tok; tok = strtok_r(NULL, ";", &tmp)) {
>> +               n = strlen(tok);
>> +               if ((tok[n - 1] == '*' && !strncmp(id, tok, n - 1)) ||
>> +                   !strcmp(id, tok)) {
> 
> We use fnmatch for a similar check:
> https://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools-next.git/tree/tools/perf/util/pmu.c?h=perf-tools-next#n1982
> 

ok

>> +                       res = true;
>> +                       goto out;
> 
> With "res=false;" above this can just be a regular break.
> 

ok, thank you!

> Thanks,
> Ian
> 
>> +               }
>> +       }
>> +       res = false;
>> +out:
>> +       free(str);
>> +       return res;
>> +}
>> +
>>  struct pmu_add_cpu_aliases_map_data {
>>         struct list_head *head;
>>         const char *name;
>> @@ -847,8 +876,8 @@ static int pmu_add_sys_aliases_iter_fn(const struct pmu_event *pe,
>>         if (!pe->compat || !pe->pmu)
>>                 return 0;
>>
>> -       if (!strcmp(pmu->id, pe->compat) &&
>> -           pmu_uncore_alias_match(pe->pmu, pmu->name)) {
>> +       if (pmu_uncore_alias_match(pe->pmu, pmu->name) &&
>> +           pmu_uncore_identifier_match(pmu->id, pe->compat)) {
>>                 __perf_pmu__new_alias(idata->head, -1,
>>                                       (char *)pe->name,
>>                                       (char *)pe->desc,
>> diff --git a/tools/perf/util/pmu.h b/tools/perf/util/pmu.h
>> index b9a02de..9d4385d 100644
>> --- a/tools/perf/util/pmu.h
>> +++ b/tools/perf/util/pmu.h
>> @@ -241,6 +241,7 @@ void pmu_add_cpu_aliases_table(struct list_head *head, struct perf_pmu *pmu,
>>  char *perf_pmu__getcpuid(struct perf_pmu *pmu);
>>  const struct pmu_events_table *pmu_events_table__find(void);
>>  const struct pmu_metrics_table *pmu_metrics_table__find(void);
>> +bool pmu_uncore_identifier_match(const char *id, const char *compat);
>>  void perf_pmu_free_alias(struct perf_pmu_alias *alias);
>>
>>  int perf_pmu__convert_scale(const char *scale, char **end, double *sval);
>> --
>> 1.8.3.1
>>