perf evlist: Rename cpus to user_requested_cpus

evlist contains cpus and all_cpus. all_cpus is the union of the cpu maps
of all evsels.

For non-task targets, cpus is set to be cpus requested from the command
line, defaulting to all online cpus if no cpus are specified.

For an uncore event, all_cpus may be just CPU 0 or every online CPU.

This causes all_cpus to have fewer values than the cpus variable which
is confusing given the 'all' in the name.

To try to make the behavior clearer, rename cpus to user_requested_cpus
and add comments on the two struct variables.

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Antonov <alexander.antonov@linux.intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Alexey Bayduraev <alexey.v.bayduraev@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: German Gomez <german.gomez@arm.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: John Garry <john.garry@huawei.com>
Cc: KP Singh <kpsingh@kernel.org>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Riccardo Mancini <rickyman7@gmail.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Suzuki Poulouse <suzuki.poulose@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yonghong Song <yhs@fb.com>
Cc: bpf@vger.kernel.org
Cc: coresight@lists.linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: netdev@vger.kernel.org
Link: http://lore.kernel.org/lkml/20220328232648.2127340-3-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 8 insertions, 7 deletions

diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 9bb79e049957..cb2cf4463c08 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -440,7 +440,7 @@ static void __evlist__disable(struct evlist *evlist, char *evsel_name)
 	bool has_imm = false;
 
 	// See explanation in evlist__close()
-	if (!cpu_map__is_dummy(evlist->core.cpus)) {
+	if (!cpu_map__is_dummy(evlist->core.user_requested_cpus)) {
 		if (affinity__setup(&saved_affinity) < 0)
 			return;
 		affinity = &saved_affinity;
@@ -500,7 +500,7 @@ static void __evlist__enable(struct evlist *evlist, char *evsel_name)
 	struct affinity saved_affinity, *affinity = NULL;
 
 	// See explanation in evlist__close()
-	if (!cpu_map__is_dummy(evlist->core.cpus)) {
+	if (!cpu_map__is_dummy(evlist->core.user_requested_cpus)) {
 		if (affinity__setup(&saved_affinity) < 0)
 			return;
 		affinity = &saved_affinity;
@@ -565,7 +565,7 @@ static int evlist__enable_event_cpu(struct evlist *evlist, struct evsel *evsel,
 static int evlist__enable_event_thread(struct evlist *evlist, struct evsel *evsel, int thread)
 {
 	int cpu;
-	int nr_cpus = perf_cpu_map__nr(evlist->core.cpus);
+	int nr_cpus = perf_cpu_map__nr(evlist->core.user_requested_cpus);
 
 	if (!evsel->core.fd)
 		return -EINVAL;
@@ -580,7 +580,7 @@ static int evlist__enable_event_thread(struct evlist *evlist, struct evsel *evse
 
 int evlist__enable_event_idx(struct evlist *evlist, struct evsel *evsel, int idx)
 {
-	bool per_cpu_mmaps = !perf_cpu_map__empty(evlist->core.cpus);
+	bool per_cpu_mmaps = !perf_cpu_map__empty(evlist->core.user_requested_cpus);
 
 	if (per_cpu_mmaps)
 		return evlist__enable_event_cpu(evlist, evsel, idx);
@@ -1301,10 +1301,11 @@ void evlist__close(struct evlist *evlist)
 	struct affinity affinity;
 
 	/*
-	 * With perf record core.cpus is usually NULL.
+	 * With perf record core.user_requested_cpus is usually NULL.
 	 * Use the old method to handle this for now.
 	 */
-	if (!evlist->core.cpus || cpu_map__is_dummy(evlist->core.cpus)) {
+	if (!evlist->core.user_requested_cpus ||
+	    cpu_map__is_dummy(evlist->core.user_requested_cpus)) {
 		evlist__for_each_entry_reverse(evlist, evsel)
 			evsel__close(evsel);
 		return;
@@ -1367,7 +1368,7 @@ int evlist__open(struct evlist *evlist)
 	 * Default: one fd per CPU, all threads, aka systemwide
 	 * as sys_perf_event_open(cpu = -1, thread = -1) is EINVAL
 	 */
-	if (evlist->core.threads == NULL && evlist->core.cpus == NULL) {
+	if (evlist->core.threads == NULL && evlist->core.user_requested_cpus == NULL) {
 		err = evlist__create_syswide_maps(evlist);
 		if (err < 0)
 			goto out_err;