[v2] perf metricgroup: Avoid scanning unnecessary PMUs for identifier match

[PATCH v2] perf metricgroup: Avoid scanning unnecessary PMUs for identifier match

Posted by Ian Rogers 1 month, 1 week ago

Only uncore PMUs can have an identifier, so add an optimized
perf_pmus__scan routine for that case to avoid all PMU types being
created.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/util/metricgroup.c | 11 +++--------
 tools/perf/util/pmus.c        | 18 +++++++++++++++++-
 tools/perf/util/pmus.h        |  1 +
 3 files changed, 21 insertions(+), 9 deletions(-)

diff --git a/tools/perf/util/metricgroup.c b/tools/perf/util/metricgroup.c
index 4db9578efd81..5a489e97c413 100644
--- a/tools/perf/util/metricgroup.c
+++ b/tools/perf/util/metricgroup.c
@@ -415,14 +415,9 @@ static int metricgroup__sys_event_iter(const struct pmu_metric *pm,
 	if (!pm->metric_expr || !pm->compat)
 		return 0;
 
-	while ((pmu = perf_pmus__scan(pmu))) {
-
-		if (!pmu->id || !pmu_uncore_identifier_match(pm->compat, pmu->id))
-			continue;
-
-		return d->fn(pm, table, d->data);
-	}
-	return 0;
+	/* Only process with the iterator if there is a a PMU that matches the ID. */
+	pmu = perf_pmus__scan_for_uncore_id(pmu, pm->compat);
+	return pmu ? d->fn(pm, table, d->data) : 0;
 }
 
 int metricgroup__for_each_metric(const struct pmu_metrics_table *table, pmu_metric_iter_fn fn,
diff --git a/tools/perf/util/pmus.c b/tools/perf/util/pmus.c
index 9a2023ceeefd..5e3f571450fe 100644
--- a/tools/perf/util/pmus.c
+++ b/tools/perf/util/pmus.c
@@ -409,7 +409,7 @@ struct perf_pmu *perf_pmus__scan_matching_wildcard(struct perf_pmu *pmu, const c
 	if (!pmu) {
 		/*
 		 * Core PMUs, other sysfs PMUs and tool PMU can have any name or
-		 * aren't wother optimizing for.
+		 * aren't worth optimizing for.
 		 */
 		unsigned int to_read_pmus =  PERF_TOOL_PMU_TYPE_PE_CORE_MASK |
 			PERF_TOOL_PMU_TYPE_PE_OTHER_MASK |
@@ -486,6 +486,22 @@ static struct perf_pmu *perf_pmus__scan_skip_duplicates(struct perf_pmu *pmu)
 	return NULL;
 }
 
+struct perf_pmu *perf_pmus__scan_for_uncore_id(struct perf_pmu *pmu, const char *compat)
+{
+	if (!pmu) {
+		/* Only uncore PMUs can have identifiers. */
+		unsigned int to_read_pmus = PERF_TOOL_PMU_TYPE_PE_OTHER_MASK;
+
+		pmu_read_sysfs(to_read_pmus);
+		pmu = list_prepare_entry(pmu, &other_pmus, list);
+	}
+	list_for_each_entry_continue(pmu, &other_pmus, list) {
+		if (pmu->id && pmu_uncore_identifier_match(compat, pmu->id))
+			return pmu;
+	}
+	return NULL;
+}
+
 const struct perf_pmu *perf_pmus__pmu_for_pmu_filter(const char *str)
 {
 	struct perf_pmu *pmu = NULL;
diff --git a/tools/perf/util/pmus.h b/tools/perf/util/pmus.h
index 7cb36863711a..0d55edb3f2fc 100644
--- a/tools/perf/util/pmus.h
+++ b/tools/perf/util/pmus.h
@@ -23,6 +23,7 @@ struct perf_pmu *perf_pmus__scan(struct perf_pmu *pmu);
 struct perf_pmu *perf_pmus__scan_core(struct perf_pmu *pmu);
 struct perf_pmu *perf_pmus__scan_for_event(struct perf_pmu *pmu, const char *event);
 struct perf_pmu *perf_pmus__scan_matching_wildcard(struct perf_pmu *pmu, const char *wildcard);
+struct perf_pmu *perf_pmus__scan_for_uncore_id(struct perf_pmu *pmu, const char *compat);
 
 const struct perf_pmu *perf_pmus__pmu_for_pmu_filter(const char *str);
 
-- 
2.54.0.545.g6539524ca2-goog

Re: [PATCH v2] perf metricgroup: Avoid scanning unnecessary PMUs for identifier match

Posted by James Clark 1 month, 1 week ago


On 30/04/2026 5:17 pm, Ian Rogers wrote:
> Only uncore PMUs can have an identifier, so add an optimized
> perf_pmus__scan routine for that case to avoid all PMU types being
> created.
> 
> Signed-off-by: Ian Rogers <irogers@google.com>
> ---
>   tools/perf/util/metricgroup.c | 11 +++--------
>   tools/perf/util/pmus.c        | 18 +++++++++++++++++-
>   tools/perf/util/pmus.h        |  1 +
>   3 files changed, 21 insertions(+), 9 deletions(-)
> 
> diff --git a/tools/perf/util/metricgroup.c b/tools/perf/util/metricgroup.c
> index 4db9578efd81..5a489e97c413 100644
> --- a/tools/perf/util/metricgroup.c
> +++ b/tools/perf/util/metricgroup.c
> @@ -415,14 +415,9 @@ static int metricgroup__sys_event_iter(const struct pmu_metric *pm,
>   	if (!pm->metric_expr || !pm->compat)
>   		return 0;
>   
> -	while ((pmu = perf_pmus__scan(pmu))) {
> -
> -		if (!pmu->id || !pmu_uncore_identifier_match(pm->compat, pmu->id))
> -			continue;
> -
> -		return d->fn(pm, table, d->data);
> -	}
> -	return 0;
> +	/* Only process with the iterator if there is a a PMU that matches the ID. */
> +	pmu = perf_pmus__scan_for_uncore_id(pmu, pm->compat);
> +	return pmu ? d->fn(pm, table, d->data) : 0;
>   }
>   
>   int metricgroup__for_each_metric(const struct pmu_metrics_table *table, pmu_metric_iter_fn fn,
> diff --git a/tools/perf/util/pmus.c b/tools/perf/util/pmus.c
> index 9a2023ceeefd..5e3f571450fe 100644
> --- a/tools/perf/util/pmus.c
> +++ b/tools/perf/util/pmus.c
> @@ -409,7 +409,7 @@ struct perf_pmu *perf_pmus__scan_matching_wildcard(struct perf_pmu *pmu, const c
>   	if (!pmu) {
>   		/*
>   		 * Core PMUs, other sysfs PMUs and tool PMU can have any name or
> -		 * aren't wother optimizing for.
> +		 * aren't worth optimizing for.
>   		 */
>   		unsigned int to_read_pmus =  PERF_TOOL_PMU_TYPE_PE_CORE_MASK |
>   			PERF_TOOL_PMU_TYPE_PE_OTHER_MASK |
> @@ -486,6 +486,22 @@ static struct perf_pmu *perf_pmus__scan_skip_duplicates(struct perf_pmu *pmu)
>   	return NULL;
>   }
>   
> +struct perf_pmu *perf_pmus__scan_for_uncore_id(struct perf_pmu *pmu, const char *compat)
> +{
> +	if (!pmu) {
> +		/* Only uncore PMUs can have identifiers. */
> +		unsigned int to_read_pmus = PERF_TOOL_PMU_TYPE_PE_OTHER_MASK;
> +
> +		pmu_read_sysfs(to_read_pmus);
> +		pmu = list_prepare_entry(pmu, &other_pmus, list);
> +	}
> +	list_for_each_entry_continue(pmu, &other_pmus, list) {
> +		if (pmu->id && pmu_uncore_identifier_match(compat, pmu->id))
> +			return pmu;
> +	}
> +	return NULL;
> +}
> +
>   const struct perf_pmu *perf_pmus__pmu_for_pmu_filter(const char *str)
>   {
>   	struct perf_pmu *pmu = NULL;
> diff --git a/tools/perf/util/pmus.h b/tools/perf/util/pmus.h
> index 7cb36863711a..0d55edb3f2fc 100644
> --- a/tools/perf/util/pmus.h
> +++ b/tools/perf/util/pmus.h
> @@ -23,6 +23,7 @@ struct perf_pmu *perf_pmus__scan(struct perf_pmu *pmu);
>   struct perf_pmu *perf_pmus__scan_core(struct perf_pmu *pmu);
>   struct perf_pmu *perf_pmus__scan_for_event(struct perf_pmu *pmu, const char *event);
>   struct perf_pmu *perf_pmus__scan_matching_wildcard(struct perf_pmu *pmu, const char *wildcard);
> +struct perf_pmu *perf_pmus__scan_for_uncore_id(struct perf_pmu *pmu, const char *compat);
>   
>   const struct perf_pmu *perf_pmus__pmu_for_pmu_filter(const char *str);
>   

Reviewed-by: James Clark <james.clark@linaro.org>

Re: [PATCH v2] perf metricgroup: Avoid scanning unnecessary PMUs for identifier match

Posted by Ian Rogers 4 weeks, 1 day ago

On Wed, May 6, 2026 at 2:12 AM James Clark <james.clark@linaro.org> wrote:
>
>
>
> On 30/04/2026 5:17 pm, Ian Rogers wrote:
> > Only uncore PMUs can have an identifier, so add an optimized
> > perf_pmus__scan routine for that case to avoid all PMU types being
> > created.
> >
> > Signed-off-by: Ian Rogers <irogers@google.com>
> > ---
> >   tools/perf/util/metricgroup.c | 11 +++--------
> >   tools/perf/util/pmus.c        | 18 +++++++++++++++++-
> >   tools/perf/util/pmus.h        |  1 +
> >   3 files changed, 21 insertions(+), 9 deletions(-)
> >
> > diff --git a/tools/perf/util/metricgroup.c b/tools/perf/util/metricgroup.c
> > index 4db9578efd81..5a489e97c413 100644
> > --- a/tools/perf/util/metricgroup.c
> > +++ b/tools/perf/util/metricgroup.c
> > @@ -415,14 +415,9 @@ static int metricgroup__sys_event_iter(const struct pmu_metric *pm,
> >       if (!pm->metric_expr || !pm->compat)
> >               return 0;
> >
> > -     while ((pmu = perf_pmus__scan(pmu))) {
> > -
> > -             if (!pmu->id || !pmu_uncore_identifier_match(pm->compat, pmu->id))
> > -                     continue;
> > -
> > -             return d->fn(pm, table, d->data);
> > -     }
> > -     return 0;
> > +     /* Only process with the iterator if there is a a PMU that matches the ID. */
> > +     pmu = perf_pmus__scan_for_uncore_id(pmu, pm->compat);
> > +     return pmu ? d->fn(pm, table, d->data) : 0;
> >   }
> >
> >   int metricgroup__for_each_metric(const struct pmu_metrics_table *table, pmu_metric_iter_fn fn,
> > diff --git a/tools/perf/util/pmus.c b/tools/perf/util/pmus.c
> > index 9a2023ceeefd..5e3f571450fe 100644
> > --- a/tools/perf/util/pmus.c
> > +++ b/tools/perf/util/pmus.c
> > @@ -409,7 +409,7 @@ struct perf_pmu *perf_pmus__scan_matching_wildcard(struct perf_pmu *pmu, const c
> >       if (!pmu) {
> >               /*
> >                * Core PMUs, other sysfs PMUs and tool PMU can have any name or
> > -              * aren't wother optimizing for.
> > +              * aren't worth optimizing for.
> >                */
> >               unsigned int to_read_pmus =  PERF_TOOL_PMU_TYPE_PE_CORE_MASK |
> >                       PERF_TOOL_PMU_TYPE_PE_OTHER_MASK |
> > @@ -486,6 +486,22 @@ static struct perf_pmu *perf_pmus__scan_skip_duplicates(struct perf_pmu *pmu)
> >       return NULL;
> >   }
> >
> > +struct perf_pmu *perf_pmus__scan_for_uncore_id(struct perf_pmu *pmu, const char *compat)
> > +{
> > +     if (!pmu) {
> > +             /* Only uncore PMUs can have identifiers. */
> > +             unsigned int to_read_pmus = PERF_TOOL_PMU_TYPE_PE_OTHER_MASK;
> > +
> > +             pmu_read_sysfs(to_read_pmus);
> > +             pmu = list_prepare_entry(pmu, &other_pmus, list);
> > +     }
> > +     list_for_each_entry_continue(pmu, &other_pmus, list) {
> > +             if (pmu->id && pmu_uncore_identifier_match(compat, pmu->id))
> > +                     return pmu;
> > +     }
> > +     return NULL;
> > +}
> > +
> >   const struct perf_pmu *perf_pmus__pmu_for_pmu_filter(const char *str)
> >   {
> >       struct perf_pmu *pmu = NULL;
> > diff --git a/tools/perf/util/pmus.h b/tools/perf/util/pmus.h
> > index 7cb36863711a..0d55edb3f2fc 100644
> > --- a/tools/perf/util/pmus.h
> > +++ b/tools/perf/util/pmus.h
> > @@ -23,6 +23,7 @@ struct perf_pmu *perf_pmus__scan(struct perf_pmu *pmu);
> >   struct perf_pmu *perf_pmus__scan_core(struct perf_pmu *pmu);
> >   struct perf_pmu *perf_pmus__scan_for_event(struct perf_pmu *pmu, const char *event);
> >   struct perf_pmu *perf_pmus__scan_matching_wildcard(struct perf_pmu *pmu, const char *wildcard);
> > +struct perf_pmu *perf_pmus__scan_for_uncore_id(struct perf_pmu *pmu, const char *compat);
> >
> >   const struct perf_pmu *perf_pmus__pmu_for_pmu_filter(const char *str);
> >
>
> Reviewed-by: James Clark <james.clark@linaro.org>

Ping.

Thanks,
Ian

Re: [PATCH v2] perf metricgroup: Avoid scanning unnecessary PMUs for identifier match

Posted by Arnaldo Carvalho de Melo 4 weeks, 1 day ago

On Thu, May 14, 2026 at 10:39:08AM -0700, Ian Rogers wrote:
> On Wed, May 6, 2026 at 2:12 AM James Clark <james.clark@linaro.org> wrote:
> > On 30/04/2026 5:17 pm, Ian Rogers wrote:
> > > Only uncore PMUs can have an identifier, so add an optimized
> > > perf_pmus__scan routine for that case to avoid all PMU types being
> > > created.
> > >
> > > Signed-off-by: Ian Rogers <irogers@google.com>
> > > ---
> > >   tools/perf/util/metricgroup.c | 11 +++--------
> > >   tools/perf/util/pmus.c        | 18 +++++++++++++++++-
> > >   tools/perf/util/pmus.h        |  1 +
> > >   3 files changed, 21 insertions(+), 9 deletions(-)
> > >
> > > diff --git a/tools/perf/util/metricgroup.c b/tools/perf/util/metricgroup.c
> > > index 4db9578efd81..5a489e97c413 100644
> > > --- a/tools/perf/util/metricgroup.c
> > > +++ b/tools/perf/util/metricgroup.c
> > > @@ -415,14 +415,9 @@ static int metricgroup__sys_event_iter(const struct pmu_metric *pm,
> > >       if (!pm->metric_expr || !pm->compat)
> > >               return 0;
> > >
> > > -     while ((pmu = perf_pmus__scan(pmu))) {
> > > -
> > > -             if (!pmu->id || !pmu_uncore_identifier_match(pm->compat, pmu->id))
> > > -                     continue;
> > > -
> > > -             return d->fn(pm, table, d->data);
> > > -     }
> > > -     return 0;
> > > +     /* Only process with the iterator if there is a a PMU that matches the ID. */
> > > +     pmu = perf_pmus__scan_for_uncore_id(pmu, pm->compat);
> > > +     return pmu ? d->fn(pm, table, d->data) : 0;
> > >   }
> > >
> > >   int metricgroup__for_each_metric(const struct pmu_metrics_table *table, pmu_metric_iter_fn fn,
> > > diff --git a/tools/perf/util/pmus.c b/tools/perf/util/pmus.c
> > > index 9a2023ceeefd..5e3f571450fe 100644
> > > --- a/tools/perf/util/pmus.c
> > > +++ b/tools/perf/util/pmus.c
> > > @@ -409,7 +409,7 @@ struct perf_pmu *perf_pmus__scan_matching_wildcard(struct perf_pmu *pmu, const c
> > >       if (!pmu) {
> > >               /*
> > >                * Core PMUs, other sysfs PMUs and tool PMU can have any name or
> > > -              * aren't wother optimizing for.
> > > +              * aren't worth optimizing for.
> > >                */
> > >               unsigned int to_read_pmus =  PERF_TOOL_PMU_TYPE_PE_CORE_MASK |
> > >                       PERF_TOOL_PMU_TYPE_PE_OTHER_MASK |
> > > @@ -486,6 +486,22 @@ static struct perf_pmu *perf_pmus__scan_skip_duplicates(struct perf_pmu *pmu)
> > >       return NULL;
> > >   }
> > >
> > > +struct perf_pmu *perf_pmus__scan_for_uncore_id(struct perf_pmu *pmu, const char *compat)
> > > +{
> > > +     if (!pmu) {
> > > +             /* Only uncore PMUs can have identifiers. */
> > > +             unsigned int to_read_pmus = PERF_TOOL_PMU_TYPE_PE_OTHER_MASK;
> > > +
> > > +             pmu_read_sysfs(to_read_pmus);
> > > +             pmu = list_prepare_entry(pmu, &other_pmus, list);
> > > +     }
> > > +     list_for_each_entry_continue(pmu, &other_pmus, list) {
> > > +             if (pmu->id && pmu_uncore_identifier_match(compat, pmu->id))
> > > +                     return pmu;
> > > +     }
> > > +     return NULL;
> > > +}
> > > +
> > >   const struct perf_pmu *perf_pmus__pmu_for_pmu_filter(const char *str)
> > >   {
> > >       struct perf_pmu *pmu = NULL;
> > > diff --git a/tools/perf/util/pmus.h b/tools/perf/util/pmus.h
> > > index 7cb36863711a..0d55edb3f2fc 100644
> > > --- a/tools/perf/util/pmus.h
> > > +++ b/tools/perf/util/pmus.h
> > > @@ -23,6 +23,7 @@ struct perf_pmu *perf_pmus__scan(struct perf_pmu *pmu);
> > >   struct perf_pmu *perf_pmus__scan_core(struct perf_pmu *pmu);
> > >   struct perf_pmu *perf_pmus__scan_for_event(struct perf_pmu *pmu, const char *event);
> > >   struct perf_pmu *perf_pmus__scan_matching_wildcard(struct perf_pmu *pmu, const char *wildcard);
> > > +struct perf_pmu *perf_pmus__scan_for_uncore_id(struct perf_pmu *pmu, const char *compat);
> > >
> > >   const struct perf_pmu *perf_pmus__pmu_for_pmu_filter(const char *str);
> > >
> >
> > Reviewed-by: James Clark <james.clark@linaro.org>
> 
> Ping.

Thanks, applied to perf-tools-next, for v7.2.

- Arnaldo

Re: [PATCH v2] perf metricgroup: Avoid scanning unnecessary PMUs for identifier match

Posted by Ian Rogers 1 month, 1 week ago

On Thu, Apr 30, 2026 at 9:17 AM Ian Rogers <irogers@google.com> wrote:
>
> Only uncore PMUs can have an identifier, so add an optimized
> perf_pmus__scan routine for that case to avoid all PMU types being
> created.
>
> Signed-off-by: Ian Rogers <irogers@google.com>

This passes Sashiko review (green). I didn't copy James Clark's
reviewed-by tag given the metricgroup code rewrite to avoid the loop,
but I think this is ready to land.

Thanks,
Ian

> ---
>  tools/perf/util/metricgroup.c | 11 +++--------
>  tools/perf/util/pmus.c        | 18 +++++++++++++++++-
>  tools/perf/util/pmus.h        |  1 +
>  3 files changed, 21 insertions(+), 9 deletions(-)
>
> diff --git a/tools/perf/util/metricgroup.c b/tools/perf/util/metricgroup.c
> index 4db9578efd81..5a489e97c413 100644
> --- a/tools/perf/util/metricgroup.c
> +++ b/tools/perf/util/metricgroup.c
> @@ -415,14 +415,9 @@ static int metricgroup__sys_event_iter(const struct pmu_metric *pm,
>         if (!pm->metric_expr || !pm->compat)
>                 return 0;
>
> -       while ((pmu = perf_pmus__scan(pmu))) {
> -
> -               if (!pmu->id || !pmu_uncore_identifier_match(pm->compat, pmu->id))
> -                       continue;
> -
> -               return d->fn(pm, table, d->data);
> -       }
> -       return 0;
> +       /* Only process with the iterator if there is a a PMU that matches the ID. */
> +       pmu = perf_pmus__scan_for_uncore_id(pmu, pm->compat);
> +       return pmu ? d->fn(pm, table, d->data) : 0;
>  }
>
>  int metricgroup__for_each_metric(const struct pmu_metrics_table *table, pmu_metric_iter_fn fn,
> diff --git a/tools/perf/util/pmus.c b/tools/perf/util/pmus.c
> index 9a2023ceeefd..5e3f571450fe 100644
> --- a/tools/perf/util/pmus.c
> +++ b/tools/perf/util/pmus.c
> @@ -409,7 +409,7 @@ struct perf_pmu *perf_pmus__scan_matching_wildcard(struct perf_pmu *pmu, const c
>         if (!pmu) {
>                 /*
>                  * Core PMUs, other sysfs PMUs and tool PMU can have any name or
> -                * aren't wother optimizing for.
> +                * aren't worth optimizing for.
>                  */
>                 unsigned int to_read_pmus =  PERF_TOOL_PMU_TYPE_PE_CORE_MASK |
>                         PERF_TOOL_PMU_TYPE_PE_OTHER_MASK |
> @@ -486,6 +486,22 @@ static struct perf_pmu *perf_pmus__scan_skip_duplicates(struct perf_pmu *pmu)
>         return NULL;
>  }
>
> +struct perf_pmu *perf_pmus__scan_for_uncore_id(struct perf_pmu *pmu, const char *compat)
> +{
> +       if (!pmu) {
> +               /* Only uncore PMUs can have identifiers. */
> +               unsigned int to_read_pmus = PERF_TOOL_PMU_TYPE_PE_OTHER_MASK;
> +
> +               pmu_read_sysfs(to_read_pmus);
> +               pmu = list_prepare_entry(pmu, &other_pmus, list);
> +       }
> +       list_for_each_entry_continue(pmu, &other_pmus, list) {
> +               if (pmu->id && pmu_uncore_identifier_match(compat, pmu->id))
> +                       return pmu;
> +       }
> +       return NULL;
> +}
> +
>  const struct perf_pmu *perf_pmus__pmu_for_pmu_filter(const char *str)
>  {
>         struct perf_pmu *pmu = NULL;
> diff --git a/tools/perf/util/pmus.h b/tools/perf/util/pmus.h
> index 7cb36863711a..0d55edb3f2fc 100644
> --- a/tools/perf/util/pmus.h
> +++ b/tools/perf/util/pmus.h
> @@ -23,6 +23,7 @@ struct perf_pmu *perf_pmus__scan(struct perf_pmu *pmu);
>  struct perf_pmu *perf_pmus__scan_core(struct perf_pmu *pmu);
>  struct perf_pmu *perf_pmus__scan_for_event(struct perf_pmu *pmu, const char *event);
>  struct perf_pmu *perf_pmus__scan_matching_wildcard(struct perf_pmu *pmu, const char *wildcard);
> +struct perf_pmu *perf_pmus__scan_for_uncore_id(struct perf_pmu *pmu, const char *compat);
>
>  const struct perf_pmu *perf_pmus__pmu_for_pmu_filter(const char *str);
>
> --
> 2.54.0.545.g6539524ca2-goog
>