tools/lib/perf/evlist.c | 5 +++-- tools/lib/perf/include/internal/evsel.h | 2 ++ tools/perf/util/evsel.c | 1 + tools/perf/util/parse-events.c | 1 + 4 files changed, 7 insertions(+), 2 deletions(-)
The PMU CPU map has different semantics for core and uncore PMUs.
For core PMUs, pmu_cpus contains the CPUs on which the event can be
opened. Intersect the user-requested CPU map with the PMU CPU map to
reject CPUs unsupported by the PMU.
For uncore PMUs, pmu_cpus is read from the PMU's cpumask sysfs attribute,
which lists the default CPU to open the event on per socket/die, not the
set of CPUs it can only be opened on. The user-requested CPU may override
these defaults, and the driver can redirect the event to the appropriate
control CPU.
Currently, __perf_evlist__propagate_maps() intersects the user-requested
CPU map with pmu_cpus for all PMUs. If the user-requested CPU is not in
pmu_cpus, the intersection becomes empty and the evsel is removed before
perf_event_open() is called.
Add evsel->is_pmu_uncore, set once from pmu->is_uncore at parse time,
to skip the intersection for uncore PMUs. Core PMUs, and other
non-core PMUs such as software events, breakpoints, or tracepoints,
continue to be restricted to their PMU CPU map.
Fixes: 811082e4b668 ("perf parse-events: Support user CPUs mixed with threads/processes")
Assisted-by: Claude Sonnet 5
Signed-off-by: Nia Su <nia.su@sifive.com>
---
Changes in v2:
- Add a dedicated is_pmu_uncore flag instead of reusing requires_cpu,
since it more precisely represents whether the PMU is uncore.
- Link to v1: https://lore.kernel.org/r/20260904-perf-evlist-uncore-cpu-b4-v1-1-604b55c025ee@sifive.com
---
tools/lib/perf/evlist.c | 5 +++--
tools/lib/perf/include/internal/evsel.h | 2 ++
tools/perf/util/evsel.c | 1 +
tools/perf/util/parse-events.c | 1 +
4 files changed, 7 insertions(+), 2 deletions(-)
diff --git a/tools/lib/perf/evlist.c b/tools/lib/perf/evlist.c
index 1f210dadd666ff818a23712ab95acaa659ccf8dc..c1c5b0684eedb7a6ab8f3df85f326fbd5ef809a2 100644
--- a/tools/lib/perf/evlist.c
+++ b/tools/lib/perf/evlist.c
@@ -79,8 +79,9 @@ static void __perf_evlist__propagate_maps(struct perf_evlist *evlist,
}
}
- /* Ensure cpus only references valid PMU CPUs. */
- if (!perf_cpu_map__has_any_cpu(evsel->cpus) &&
+ /* Ensure cpus only references valid PMU CPUs, except for uncore PMUs. */
+ if (!evsel->is_pmu_uncore &&
+ !perf_cpu_map__has_any_cpu(evsel->cpus) &&
!perf_cpu_map__is_subset(evsel->pmu_cpus, evsel->cpus)) {
struct perf_cpu_map *tmp = perf_cpu_map__intersect(evsel->pmu_cpus, evsel->cpus);
diff --git a/tools/lib/perf/include/internal/evsel.h b/tools/lib/perf/include/internal/evsel.h
index b988034f13710ec4d49d942d486c4b9afe21a1f0..35447bed0f9586b538dad40c223e70d50486c5f6 100644
--- a/tools/lib/perf/include/internal/evsel.h
+++ b/tools/lib/perf/include/internal/evsel.h
@@ -128,6 +128,8 @@ struct perf_evsel {
bool requires_cpu;
/** Is the PMU for the event a core one? Effects the handling of own_cpus. */
bool is_pmu_core;
+ /** Is the PMU for the event an uncore one? */
+ bool is_pmu_uncore;
/** Does the evsel on read on the first CPU index such as tool time events? */
bool reads_only_on_cpu_idx0;
int idx;
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index d4cb455f4a7d45ae2f9133709ff3248b54163ce0..5acec3f6345099ef9e46e81614b9df2595925b1c 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -551,6 +551,7 @@ struct evsel *evsel__clone(struct evsel *orig)
evsel->core.system_wide = orig->core.system_wide;
evsel->core.requires_cpu = orig->core.requires_cpu;
evsel->core.is_pmu_core = orig->core.is_pmu_core;
+ evsel->core.is_pmu_uncore = orig->core.is_pmu_uncore;
if (orig->name) {
evsel->name = strdup(orig->name);
diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index cc7ad331a49f34536f66724370b8bb94ab65bacd..8302be207c1d6ecf8ae6fd67f54d66d08d50e01c 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -269,6 +269,7 @@ __add_event(struct list_head *list, int *idx,
evsel->core.pmu_cpus = pmu_cpus;
evsel->core.requires_cpu = pmu ? pmu->is_uncore : false;
evsel->core.is_pmu_core = is_pmu_core;
+ evsel->core.is_pmu_uncore = pmu ? pmu->is_uncore : false;
evsel->core.reads_only_on_cpu_idx0 = perf_pmu__reads_only_on_cpu_idx0(attr);
evsel->pmu = pmu;
evsel->alternate_hw_config = alternate_hw_config;
---
base-commit: 73e3f0710014fe6d4ed98cfc02292f6121db7558
change-id: 20260904-perf-evlist-uncore-cpu-b4-418af0f17c80
--On Wed, Sep 9, 2026 at 7:31 PM Nia Su <nia.su@sifive.com> wrote:
>
> The PMU CPU map has different semantics for core and uncore PMUs.
>
> For core PMUs, pmu_cpus contains the CPUs on which the event can be
> opened. Intersect the user-requested CPU map with the PMU CPU map to
> reject CPUs unsupported by the PMU.
>
> For uncore PMUs, pmu_cpus is read from the PMU's cpumask sysfs attribute,
> which lists the default CPU to open the event on per socket/die, not the
> set of CPUs it can only be opened on. The user-requested CPU may override
> these defaults, and the driver can redirect the event to the appropriate
> control CPU.
>
> Currently, __perf_evlist__propagate_maps() intersects the user-requested
> CPU map with pmu_cpus for all PMUs. If the user-requested CPU is not in
> pmu_cpus, the intersection becomes empty and the evsel is removed before
> perf_event_open() is called.
>
> Add evsel->is_pmu_uncore, set once from pmu->is_uncore at parse time,
> to skip the intersection for uncore PMUs. Core PMUs, and other
> non-core PMUs such as software events, breakpoints, or tracepoints,
> continue to be restricted to their PMU CPU map.
>
> Fixes: 811082e4b668 ("perf parse-events: Support user CPUs mixed with threads/processes")
>
> Assisted-by: Claude Sonnet 5
> Signed-off-by: Nia Su <nia.su@sifive.com>
Reviewed-by: Ian Rogers <irogers@google.com>
Thanks,
Ian
> ---
> Changes in v2:
> - Add a dedicated is_pmu_uncore flag instead of reusing requires_cpu,
> since it more precisely represents whether the PMU is uncore.
> - Link to v1: https://lore.kernel.org/r/20260904-perf-evlist-uncore-cpu-b4-v1-1-604b55c025ee@sifive.com
> ---
> tools/lib/perf/evlist.c | 5 +++--
> tools/lib/perf/include/internal/evsel.h | 2 ++
> tools/perf/util/evsel.c | 1 +
> tools/perf/util/parse-events.c | 1 +
> 4 files changed, 7 insertions(+), 2 deletions(-)
>
> diff --git a/tools/lib/perf/evlist.c b/tools/lib/perf/evlist.c
> index 1f210dadd666ff818a23712ab95acaa659ccf8dc..c1c5b0684eedb7a6ab8f3df85f326fbd5ef809a2 100644
> --- a/tools/lib/perf/evlist.c
> +++ b/tools/lib/perf/evlist.c
> @@ -79,8 +79,9 @@ static void __perf_evlist__propagate_maps(struct perf_evlist *evlist,
> }
> }
>
> - /* Ensure cpus only references valid PMU CPUs. */
> - if (!perf_cpu_map__has_any_cpu(evsel->cpus) &&
> + /* Ensure cpus only references valid PMU CPUs, except for uncore PMUs. */
> + if (!evsel->is_pmu_uncore &&
> + !perf_cpu_map__has_any_cpu(evsel->cpus) &&
> !perf_cpu_map__is_subset(evsel->pmu_cpus, evsel->cpus)) {
> struct perf_cpu_map *tmp = perf_cpu_map__intersect(evsel->pmu_cpus, evsel->cpus);
>
> diff --git a/tools/lib/perf/include/internal/evsel.h b/tools/lib/perf/include/internal/evsel.h
> index b988034f13710ec4d49d942d486c4b9afe21a1f0..35447bed0f9586b538dad40c223e70d50486c5f6 100644
> --- a/tools/lib/perf/include/internal/evsel.h
> +++ b/tools/lib/perf/include/internal/evsel.h
> @@ -128,6 +128,8 @@ struct perf_evsel {
> bool requires_cpu;
> /** Is the PMU for the event a core one? Effects the handling of own_cpus. */
> bool is_pmu_core;
> + /** Is the PMU for the event an uncore one? */
> + bool is_pmu_uncore;
> /** Does the evsel on read on the first CPU index such as tool time events? */
> bool reads_only_on_cpu_idx0;
> int idx;
> diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
> index d4cb455f4a7d45ae2f9133709ff3248b54163ce0..5acec3f6345099ef9e46e81614b9df2595925b1c 100644
> --- a/tools/perf/util/evsel.c
> +++ b/tools/perf/util/evsel.c
> @@ -551,6 +551,7 @@ struct evsel *evsel__clone(struct evsel *orig)
> evsel->core.system_wide = orig->core.system_wide;
> evsel->core.requires_cpu = orig->core.requires_cpu;
> evsel->core.is_pmu_core = orig->core.is_pmu_core;
> + evsel->core.is_pmu_uncore = orig->core.is_pmu_uncore;
>
> if (orig->name) {
> evsel->name = strdup(orig->name);
> diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
> index cc7ad331a49f34536f66724370b8bb94ab65bacd..8302be207c1d6ecf8ae6fd67f54d66d08d50e01c 100644
> --- a/tools/perf/util/parse-events.c
> +++ b/tools/perf/util/parse-events.c
> @@ -269,6 +269,7 @@ __add_event(struct list_head *list, int *idx,
> evsel->core.pmu_cpus = pmu_cpus;
> evsel->core.requires_cpu = pmu ? pmu->is_uncore : false;
> evsel->core.is_pmu_core = is_pmu_core;
> + evsel->core.is_pmu_uncore = pmu ? pmu->is_uncore : false;
> evsel->core.reads_only_on_cpu_idx0 = perf_pmu__reads_only_on_cpu_idx0(attr);
> evsel->pmu = pmu;
> evsel->alternate_hw_config = alternate_hw_config;
>
> ---
> base-commit: 73e3f0710014fe6d4ed98cfc02292f6121db7558
> change-id: 20260904-perf-evlist-uncore-cpu-b4-418af0f17c80
>
> --
>
On Tue, Sep 15, 2026 at 12:42:43PM -0700, Ian Rogers wrote:
> On Wed, Sep 9, 2026 at 7:31 PM Nia Su <nia.su@sifive.com> wrote:
> > The PMU CPU map has different semantics for core and uncore PMUs.
<SNIP>
> > Add evsel->is_pmu_uncore, set once from pmu->is_uncore at parse time,
> > to skip the intersection for uncore PMUs. Core PMUs, and other
> > non-core PMUs such as software events, breakpoints, or tracepoints,
> > continue to be restricted to their PMU CPU map.
> > Fixes: 811082e4b668 ("perf parse-events: Support user CPUs mixed with threads/processes")
> > Assisted-by: Claude Sonnet 5
> > Signed-off-by: Nia Su <nia.su@sifive.com>
> Reviewed-by: Ian Rogers <irogers@google.com>
Thanks, applied to perf-tools-next, for v7.4.
- Arnaldo
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