Re: [PATCH v3 3/5] perf pmu: Rename name matching for no suffix or wildcard variants

[Namhyung Kim <namhyung@kernel.org>]

On Mon, Feb 03, 2025 at 03:10:04PM -0800, Ian Rogers wrote:
> On Mon, Feb 3, 2025 at 3:00 PM Namhyung Kim <namhyung@kernel.org> wrote:
> >
> > Hi Ian,
> >
> > On Fri, Jan 31, 2025 at 11:43:18PM -0800, Ian Rogers wrote:
> > > Wildcard PMU naming will match a name like pmu_1 to a PMU name like
> > > pmu_10 but not to a PMU name like pmu_2 as the suffix forms part of
> > > the match. No suffix matching will match pmu_10 to either pmu_1 or
> > > pmu_2. Add or rename matching functions on PMU to make it clearer what
> > > kind of matching is being performed.
> > >
> > > Signed-off-by: Ian Rogers <irogers@google.com>
> > > ---
> > >  tools/perf/pmu-events/empty-pmu-events.c |   8 +-
> > >  tools/perf/pmu-events/jevents.py         |   8 +-
> > >  tools/perf/tests/pmu.c                   |  85 ++++----
> > >  tools/perf/util/parse-events.c           |   2 +-
> > >  tools/perf/util/pmu.c                    | 256 ++++++++++++++++-------
> > >  tools/perf/util/pmu.h                    |   5 +-
> > >  6 files changed, 235 insertions(+), 129 deletions(-)
> > >
> > [...]
> > > diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
> > > index 6206c8fe2bf9..c2a15b0259cf 100644
> > > --- a/tools/perf/util/pmu.c
> > > +++ b/tools/perf/util/pmu.c
> > > @@ -847,21 +847,23 @@ static size_t pmu_deduped_name_len(const struct perf_pmu *pmu, const char *name,
> > >  }
> > >
> > >  /**
> > > - * perf_pmu__match_ignoring_suffix - Does the pmu_name match tok ignoring any
> > > - *                                   trailing suffix? The Suffix must be in form
> > > - *                                   tok_{digits}, or tok{digits}.
> > > + * perf_pmu__match_wildcard - Does the pmu_name start with tok and is then only
> > > + *                            followed by nothing or a suffix? tok may contain
> > > + *                            part of a suffix.
> > >   * @pmu_name: The pmu_name with possible suffix.
> > > - * @tok: The possible match to pmu_name without suffix.
> > > + * @tok: The wildcard argument to match.
> > >   */
> > > -static bool perf_pmu__match_ignoring_suffix(const char *pmu_name, const char *tok)
> > > +static bool perf_pmu__match_wildcard(const char *pmu_name, const char *tok)
> >
> > It'd be nice if we use a function prefix with "__" only if the first
> > argument is the corresponding type.  How about renaming it to
> > pmu_name_match_wildcard() and others?
> >
> > Otherwise, looks good to me.
> 
> I think the intent is to make them look like (in the C++ sense) static
> member functions. I was following the existing convention as with
> perf_pmu__event_source_devices_scnprintf,
> perf_pmu__pathname_scnprintf, perf_pmu__convert_scale,
> perf_pmu__event_source_devices_fd,  perf_pmu__pathname_fd, all the
> perf_pmus functions, etc.

I still think it's better to match the prefix with the data type but we
can fix them all later.

Thanks,
Namhyung

> >
> > >  {
> > >       const char *p, *suffix;
> > >       bool has_hex = false;
> > > +     size_t tok_len = strlen(tok);
> > >
> > > -     if (strncmp(pmu_name, tok, strlen(tok)))
> > > +     /* Check start of pmu_name for equality. */
> > > +     if (strncmp(pmu_name, tok, tok_len))
> > >               return false;
> > >
> > > -     suffix = p = pmu_name + strlen(tok);
> > > +     suffix = p = pmu_name + tok_len;
> > >       if (*p == 0)
> > >               return true;
> > >
> > > @@ -887,60 +889,84 @@ static bool perf_pmu__match_ignoring_suffix(const char *pmu_name, const char *to
> > >  }
> > >
> > >  /**
> > > - * pmu_uncore_alias_match - does name match the PMU name?
> > > - * @pmu_name: the json struct pmu_event name. This may lack a suffix (which
> > > + * perf_pmu__match_ignoring_suffix_uncore - Does the pmu_name match tok ignoring
> > > + *                                          any trailing suffix on pmu_name and
> > > + *                                          tok?  The Suffix must be in form
> > > + *                                          tok_{digits}, or tok{digits}.
> > > + * @pmu_name: The pmu_name with possible suffix.
> > > + * @tok: The possible match to pmu_name.
> > > + */
> > > +static bool perf_pmu__match_ignoring_suffix_uncore(const char *pmu_name, const char *tok)
> > > +{
> > > +     size_t pmu_name_len, tok_len;
> > > +
> > > +     /* For robustness, check for NULL. */
> > > +     if (pmu_name == NULL)
> > > +             return tok == NULL;
> > > +
> > > +     /* uncore_ prefixes are ignored. */
> > > +     if (!strncmp(pmu_name, "uncore_", 7))
> > > +             pmu_name += 7;
> > > +     if (!strncmp(tok, "uncore_", 7))
> > > +             tok += 7;
> > > +
> > > +     pmu_name_len = pmu_name_len_no_suffix(pmu_name);
> > > +     tok_len = pmu_name_len_no_suffix(tok);
> > > +     if (pmu_name_len != tok_len)
> > > +             return false;
> > > +
> > > +     return strncmp(pmu_name, tok, pmu_name_len) == 0;
> > > +}
> > > +
> > > +
> > > +/**
> > > + * perf_pmu__match_wildcard_uncore - does to_match match the PMU's name?
> > > + * @pmu_name: The pmu->name or pmu->alias to match against.
> > > + * @to_match: the json struct pmu_event name. This may lack a suffix (which
> > >   *            matches) or be of the form "socket,pmuname" which will match
> > >   *            "socketX_pmunameY".
> > > - * @name: a real full PMU name as from sysfs.
> > >   */
> > > -static bool pmu_uncore_alias_match(const char *pmu_name, const char *name)
> > > +static bool perf_pmu__match_wildcard_uncore(const char *pmu_name, const char *to_match)
> > >  {
> > > -     char *tmp = NULL, *tok, *str;
> > > -     bool res;
> > > -
> > > -     if (strchr(pmu_name, ',') == NULL)
> > > -             return perf_pmu__match_ignoring_suffix(name, pmu_name);
> > > +     char *mutable_to_match, *tok, *tmp;
> > >
> > > -     str = strdup(pmu_name);
> > > -     if (!str)
> > > +     if (!pmu_name)
> > >               return false;
> > >
> > > -     /*
> > > -      * uncore alias may be from different PMU with common prefix
> > > -      */
> > > -     tok = strtok_r(str, ",", &tmp);
> > > -     if (strncmp(pmu_name, tok, strlen(tok))) {
> > > -             res = false;
> > > -             goto out;
> > > -     }
> > > +     /* uncore_ prefixes are ignored. */
> > > +     if (!strncmp(pmu_name, "uncore_", 7))
> > > +             pmu_name += 7;
> > > +     if (!strncmp(to_match, "uncore_", 7))
> > > +             to_match += 7;
> > >
> > > -     /*
> > > -      * Match more complex aliases where the alias name is a comma-delimited
> > > -      * list of tokens, orderly contained in the matching PMU name.
> > > -      *
> > > -      * Example: For alias "socket,pmuname" and PMU "socketX_pmunameY", we
> > > -      *          match "socket" in "socketX_pmunameY" and then "pmuname" in
> > > -      *          "pmunameY".
> > > -      */
> > > -     while (1) {
> > > -             char *next_tok = strtok_r(NULL, ",", &tmp);
> > > +     if (strchr(to_match, ',') == NULL)
> > > +             return perf_pmu__match_wildcard(pmu_name, to_match);
> > >
> > > -             name = strstr(name, tok);
> > > -             if (!name ||
> > > -                 (!next_tok && !perf_pmu__match_ignoring_suffix(name, tok))) {
> > > -                     res = false;
> > > -                     goto out;
> > > +     /* Process comma separated list of PMU name components. */
> > > +     mutable_to_match = strdup(to_match);
> > > +     if (!mutable_to_match)
> > > +             return false;
> > > +
> > > +     tok = strtok_r(mutable_to_match, ",", &tmp);
> > > +     while (tok) {
> > > +             size_t tok_len = strlen(tok);
> > > +
> > > +             if (strncmp(pmu_name, tok, tok_len)) {
> > > +                     /* Mismatch between part of pmu_name and tok. */
> > > +                     free(mutable_to_match);
> > > +                     return false;
> > >               }
> > > -             if (!next_tok)
> > > -                     break;
> > > -             tok = next_tok;
> > > -             name += strlen(tok);
> > > +             /* Move pmu_name forward over tok and suffix. */
> > > +             pmu_name += tok_len;
> > > +             while (*pmu_name != '\0' && isdigit(*pmu_name))
> > > +                     pmu_name++;
> > > +             if (*pmu_name == '_')
> > > +                     pmu_name++;
> > > +
> > > +             tok = strtok_r(NULL, ",", &tmp);
> > >       }
> > > -
> > > -     res = true;
> > > -out:
> > > -     free(str);
> > > -     return res;
> > > +     free(mutable_to_match);
> > > +     return *pmu_name == '\0';
> > >  }
> > >
> > >  bool pmu_uncore_identifier_match(const char *compat, const char *id)
> > > @@ -1003,11 +1029,19 @@ static int pmu_add_sys_aliases_iter_fn(const struct pmu_event *pe,
> > >  {
> > >       struct perf_pmu *pmu = vdata;
> > >
> > > -     if (!pe->compat || !pe->pmu)
> > > +     if (!pe->compat || !pe->pmu) {
> > > +             /* No data to match. */
> > >               return 0;
> > > +     }
> > > +
> > > +     if (!perf_pmu__match_wildcard_uncore(pmu->name, pe->pmu) &&
> > > +         !perf_pmu__match_wildcard_uncore(pmu->alias_name, pe->pmu)) {
> > > +             /* PMU name/alias_name don't match. */
> > > +             return 0;
> > > +     }
> > >
> > > -     if (pmu_uncore_alias_match(pe->pmu, pmu->name) &&
> > > -         pmu_uncore_identifier_match(pe->compat, pmu->id)) {
> > > +     if (pmu_uncore_identifier_match(pe->compat, pmu->id)) {
> > > +             /* Id matched. */
> > >               perf_pmu__new_alias(pmu,
> > >                               pe->name,
> > >                               pe->desc,
> > > @@ -1016,7 +1050,6 @@ static int pmu_add_sys_aliases_iter_fn(const struct pmu_event *pe,
> > >                               pe,
> > >                               EVENT_SRC_SYS_JSON);
> > >       }
> > > -
> > >       return 0;
> > >  }
> > >
> > > @@ -1974,15 +2007,82 @@ int perf_pmu__for_each_event(struct perf_pmu *pmu, bool skip_duplicate_pmus,
> > >       return ret;
> > >  }
> > >
> > > -bool pmu__name_match(const struct perf_pmu *pmu, const char *pmu_name)
> > > +static bool perf_pmu___name_match(const struct perf_pmu *pmu, const char *to_match, bool wildcard)
> > >  {
> > > -     return !strcmp(pmu->name, pmu_name) ||
> > > -             (pmu->is_uncore && pmu_uncore_alias_match(pmu_name, pmu->name)) ||
> > > +     const char *names[2] = {
> > > +             pmu->name,
> > > +             pmu->alias_name,
> > > +     };
> > > +     if (pmu->is_core) {
> > > +             for (size_t i = 0; i < ARRAY_SIZE(names); i++) {
> > > +                     const char *name = names[i];
> > > +
> > > +                     if (!name)
> > > +                             continue;
> > > +
> > > +                     if (!strcmp(name, to_match)) {
> > > +                             /* Exact name match. */
> > > +                             return true;
> > > +                     }
> > > +             }
> > > +             if (!strcmp(to_match, "default_core")) {
> > > +                     /*
> > > +                      * jevents and tests use default_core as a marker for any core
> > > +                      * PMU as the PMU name varies across architectures.
> > > +                      */
> > > +                     return true;
> > > +             }
> > > +             return false;
> > > +     }
> > > +     if (!pmu->is_uncore) {
> > >               /*
> > > -              * jevents and tests use default_core as a marker for any core
> > > -              * PMU as the PMU name varies across architectures.
> > > +              * PMU isn't core or uncore, some kind of broken CPU mask
> > > +              * situation. Only match exact name.
> > >                */
> > > -             (pmu->is_core && !strcmp(pmu_name, "default_core"));
> > > +             for (size_t i = 0; i < ARRAY_SIZE(names); i++) {
> > > +                     const char *name = names[i];
> > > +
> > > +                     if (!name)
> > > +                             continue;
> > > +
> > > +                     if (!strcmp(name, to_match)) {
> > > +                             /* Exact name match. */
> > > +                             return true;
> > > +                     }
> > > +             }
> > > +             return false;
> > > +     }
> > > +     for (size_t i = 0; i < ARRAY_SIZE(names); i++) {
> > > +             const char *name = names[i];
> > > +
> > > +             if (wildcard && perf_pmu__match_wildcard_uncore(name, to_match))
> > > +                     return true;
> > > +             if (!wildcard && perf_pmu__match_ignoring_suffix_uncore(name, to_match))
> > > +                     return true;
> > > +     }
> > > +     return false;
> > > +}
> > > +
> > > +/**
> > > + * perf_pmu__name_wildcard_match - Called by the jevents generated code to see
> > > + *                                 if pmu matches the json to_match string.
> > > + * @pmu: The pmu whose name/alias to match.
> > > + * @to_match: The possible match to pmu_name.
> > > + */
> > > +bool perf_pmu__name_wildcard_match(const struct perf_pmu *pmu, const char *to_match)
> > > +{
> > > +     return perf_pmu___name_match(pmu, to_match, /*wildcard=*/true);
> > > +}
> > > +
> > > +/**
> > > + * perf_pmu__name_no_suffix_match - Does pmu's name match to_match ignoring any
> > > + *                                  trailing suffix on the pmu_name and/or tok?
> > > + * @pmu: The pmu whose name/alias to match.
> > > + * @to_match: The possible match to pmu_name.
> > > + */
> > > +bool perf_pmu__name_no_suffix_match(const struct perf_pmu *pmu, const char *to_match)
> > > +{
> > > +     return perf_pmu___name_match(pmu, to_match, /*wildcard=*/false);
> > >  }
> > >
> > >  bool perf_pmu__is_software(const struct perf_pmu *pmu)
> > > @@ -2229,29 +2329,31 @@ void perf_pmu__warn_invalid_config(struct perf_pmu *pmu, __u64 config,
> > >                  name ?: "N/A", buf, config_name, config);
> > >  }
> > >
> > > -bool perf_pmu__match(const struct perf_pmu *pmu, const char *tok)
> > > +bool perf_pmu__wildcard_match(const struct perf_pmu *pmu, const char *wildcard_to_match)
> > >  {
> > > -     const char *name = pmu->name;
> > > -     bool need_fnmatch = strisglob(tok);
> > > +     const char *names[2] = {
> > > +             pmu->name,
> > > +             pmu->alias_name,
> > > +     };
> > > +     bool need_fnmatch = strisglob(wildcard_to_match);
> > >
> > > -     if (!strncmp(tok, "uncore_", 7))
> > > -             tok += 7;
> > > -     if (!strncmp(name, "uncore_", 7))
> > > -             name += 7;
> > > +     if (!strncmp(wildcard_to_match, "uncore_", 7))
> > > +             wildcard_to_match += 7;
> > >
> > > -     if (perf_pmu__match_ignoring_suffix(name, tok) ||
> > > -         (need_fnmatch && !fnmatch(tok, name, 0)))
> > > -             return true;
> > > +     for (size_t i = 0; i < ARRAY_SIZE(names); i++) {
> > > +             const char *pmu_name = names[i];
> > >
> > > -     name = pmu->alias_name;
> > > -     if (!name)
> > > -             return false;
> > > +             if (!pmu_name)
> > > +                     continue;
> > >
> > > -     if (!strncmp(name, "uncore_", 7))
> > > -             name += 7;
> > > +             if (!strncmp(pmu_name, "uncore_", 7))
> > > +                     pmu_name += 7;
> > >
> > > -     return perf_pmu__match_ignoring_suffix(name, tok) ||
> > > -             (need_fnmatch && !fnmatch(tok, name, 0));
> > > +             if (perf_pmu__match_wildcard(pmu_name, wildcard_to_match) ||
> > > +                 (need_fnmatch && !fnmatch(wildcard_to_match, pmu_name, 0)))
> > > +                     return true;
> > > +     }
> > > +     return false;
> > >  }
> > >
> > >  int perf_pmu__event_source_devices_scnprintf(char *pathname, size_t size)
> > > diff --git a/tools/perf/util/pmu.h b/tools/perf/util/pmu.h
> > > index edd36c20aedc..f5306428c03f 100644
> > > --- a/tools/perf/util/pmu.h
> > > +++ b/tools/perf/util/pmu.h
> > > @@ -240,7 +240,8 @@ bool perf_pmu__have_event(struct perf_pmu *pmu, const char *name);
> > >  size_t perf_pmu__num_events(struct perf_pmu *pmu);
> > >  int perf_pmu__for_each_event(struct perf_pmu *pmu, bool skip_duplicate_pmus,
> > >                            void *state, pmu_event_callback cb);
> > > -bool pmu__name_match(const struct perf_pmu *pmu, const char *pmu_name);
> > > +bool perf_pmu__name_wildcard_match(const struct perf_pmu *pmu, const char *to_match);
> > > +bool perf_pmu__name_no_suffix_match(const struct perf_pmu *pmu, const char *to_match);
> > >
> > >  /**
> > >   * perf_pmu_is_software - is the PMU a software PMU as in it uses the
> > > @@ -275,7 +276,7 @@ void perf_pmu__warn_invalid_config(struct perf_pmu *pmu, __u64 config,
> > >                                  const char *config_name);
> > >  void perf_pmu__warn_invalid_formats(struct perf_pmu *pmu);
> > >
> > > -bool perf_pmu__match(const struct perf_pmu *pmu, const char *tok);
> > > +bool perf_pmu__wildcard_match(const struct perf_pmu *pmu, const char *wildcard_to_match);
> > >
> > >  int perf_pmu__event_source_devices_scnprintf(char *pathname, size_t size);
> > >  int perf_pmu__pathname_scnprintf(char *buf, size_t size,
> > > --
> > > 2.48.1.362.g079036d154-goog
> > >