[PATCH v3 11/15] perf evsel: Add evsel__open_per_cpu_and_thread

From: Ian Rogers
Date: Fri Jul 18 2025 - 23:08:03 EST


Add evsel__open_per_cpu_and_thread that combines the operation of
evsel__open_per_cpu and evsel__open_per_thread so that an event
without the "any" cpumask can be opened with its cpumask and with
threads it specifies. Change the implementation of evsel__open_per_cpu
and evsel__open_per_thread to use evsel__open_per_cpu_and_thread to
make the implementation of those functions clearer.

Reviewed-by: Thomas Falcon <thomas.falcon@xxxxxxxxx>
Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
---
tools/perf/util/evsel.c | 23 +++++++++++++++++++----
tools/perf/util/evsel.h | 3 +++
2 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index af2b26c6456a..ae11df1e7902 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -2761,17 +2761,32 @@ void evsel__close(struct evsel *evsel)
perf_evsel__free_id(&evsel->core);
}

-int evsel__open_per_cpu(struct evsel *evsel, struct perf_cpu_map *cpus, int cpu_map_idx)
+int evsel__open_per_cpu_and_thread(struct evsel *evsel,
+ struct perf_cpu_map *cpus, int cpu_map_idx,
+ struct perf_thread_map *threads)
{
if (cpu_map_idx == -1)
- return evsel__open_cpu(evsel, cpus, NULL, 0, perf_cpu_map__nr(cpus));
+ return evsel__open_cpu(evsel, cpus, threads, 0, perf_cpu_map__nr(cpus));

- return evsel__open_cpu(evsel, cpus, NULL, cpu_map_idx, cpu_map_idx + 1);
+ return evsel__open_cpu(evsel, cpus, threads, cpu_map_idx, cpu_map_idx + 1);
+}
+
+int evsel__open_per_cpu(struct evsel *evsel, struct perf_cpu_map *cpus, int cpu_map_idx)
+{
+ struct perf_thread_map *threads = thread_map__new_by_tid(-1);
+ int ret = evsel__open_per_cpu_and_thread(evsel, cpus, cpu_map_idx, threads);
+
+ perf_thread_map__put(threads);
+ return ret;
}

int evsel__open_per_thread(struct evsel *evsel, struct perf_thread_map *threads)
{
- return evsel__open(evsel, NULL, threads);
+ struct perf_cpu_map *cpus = perf_cpu_map__new_any_cpu();
+ int ret = evsel__open_per_cpu_and_thread(evsel, cpus, -1, threads);
+
+ perf_cpu_map__put(cpus);
+ return ret;
}

static int perf_evsel__parse_id_sample(const struct evsel *evsel,
diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
index cefa8e64c0d5..8e79eb6d41b3 100644
--- a/tools/perf/util/evsel.h
+++ b/tools/perf/util/evsel.h
@@ -351,6 +351,9 @@ int evsel__enable(struct evsel *evsel);
int evsel__disable(struct evsel *evsel);
int evsel__disable_cpu(struct evsel *evsel, int cpu_map_idx);

+int evsel__open_per_cpu_and_thread(struct evsel *evsel,
+ struct perf_cpu_map *cpus, int cpu_map_idx,
+ struct perf_thread_map *threads);
int evsel__open_per_cpu(struct evsel *evsel, struct perf_cpu_map *cpus, int cpu_map_idx);
int evsel__open_per_thread(struct evsel *evsel, struct perf_thread_map *threads);
int evsel__open(struct evsel *evsel, struct perf_cpu_map *cpus,
--
2.50.0.727.gbf7dc18ff4-goog