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>

Author: captain5050

tools/lib/perf/evlist.c

@@ -41,10 +41,10 @@ static void __perf_evlist__propagate_maps(struct perf_evlist *evlist,
 	 */
 	if (!evsel->own_cpus || evlist->has_user_cpus) {
 		perf_cpu_map__put(evsel->cpus);
-		evsel->cpus = perf_cpu_map__get(evlist->cpus);
-	} else if (!evsel->system_wide && perf_cpu_map__empty(evlist->cpus)) {
+		evsel->cpus = perf_cpu_map__get(evlist->user_requested_cpus);
+	} else if (!evsel->system_wide && perf_cpu_map__empty(evlist->user_requested_cpus)) {
 		perf_cpu_map__put(evsel->cpus);
-		evsel->cpus = perf_cpu_map__get(evlist->cpus);
+		evsel->cpus = perf_cpu_map__get(evlist->user_requested_cpus);
 	} else if (evsel->cpus != evsel->own_cpus) {
 		perf_cpu_map__put(evsel->cpus);
 		evsel->cpus = perf_cpu_map__get(evsel->own_cpus);
@@ -123,10 +123,10 @@ static void perf_evlist__purge(struct perf_evlist *evlist)
 
 void perf_evlist__exit(struct perf_evlist *evlist)
 {
-	perf_cpu_map__put(evlist->cpus);
+	perf_cpu_map__put(evlist->user_requested_cpus);
 	perf_cpu_map__put(evlist->all_cpus);
 	perf_thread_map__put(evlist->threads);
-	evlist->cpus = NULL;
+	evlist->user_requested_cpus = NULL;
 	evlist->all_cpus = NULL;
 	evlist->threads = NULL;
 	fdarray__exit(&evlist->pollfd);
@@ -155,9 +155,9 @@ void perf_evlist__set_maps(struct perf_evlist *evlist,
 	 * original reference count of 1.  If that is not the case it is up to
 	 * the caller to increase the reference count.
 	 */
-	if (cpus != evlist->cpus) {
-		perf_cpu_map__put(evlist->cpus);
-		evlist->cpus = perf_cpu_map__get(cpus);
+	if (cpus != evlist->user_requested_cpus) {
+		perf_cpu_map__put(evlist->user_requested_cpus);
+		evlist->user_requested_cpus = perf_cpu_map__get(cpus);
 	}
 
 	if (threads != evlist->threads) {
@@ -294,7 +294,7 @@ int perf_evlist__id_add_fd(struct perf_evlist *evlist,
 
 int perf_evlist__alloc_pollfd(struct perf_evlist *evlist)
 {
-	int nr_cpus = perf_cpu_map__nr(evlist->cpus);
+	int nr_cpus = perf_cpu_map__nr(evlist->user_requested_cpus);
 	int nr_threads = perf_thread_map__nr(evlist->threads);
 	int nfds = 0;
 	struct perf_evsel *evsel;
@@ -426,7 +426,7 @@ mmap_per_evsel(struct perf_evlist *evlist, struct perf_evlist_mmap_ops *ops,
 	       int idx, struct perf_mmap_param *mp, int cpu_idx,
 	       int thread, int *_output, int *_output_overwrite)
 {
-	struct perf_cpu evlist_cpu = perf_cpu_map__cpu(evlist->cpus, cpu_idx);
+	struct perf_cpu evlist_cpu = perf_cpu_map__cpu(evlist->user_requested_cpus, cpu_idx);
 	struct perf_evsel *evsel;
 	int revent;
 
@@ -536,7 +536,7 @@ mmap_per_cpu(struct perf_evlist *evlist, struct perf_evlist_mmap_ops *ops,
 	     struct perf_mmap_param *mp)
 {
 	int nr_threads = perf_thread_map__nr(evlist->threads);
-	int nr_cpus    = perf_cpu_map__nr(evlist->cpus);
+	int nr_cpus    = perf_cpu_map__nr(evlist->user_requested_cpus);
 	int cpu, thread;
 
 	for (cpu = 0; cpu < nr_cpus; cpu++) {
@@ -564,8 +564,8 @@ static int perf_evlist__nr_mmaps(struct perf_evlist *evlist)
 {
 	int nr_mmaps;
 
-	nr_mmaps = perf_cpu_map__nr(evlist->cpus);
-	if (perf_cpu_map__empty(evlist->cpus))
+	nr_mmaps = perf_cpu_map__nr(evlist->user_requested_cpus);
+	if (perf_cpu_map__empty(evlist->user_requested_cpus))
 		nr_mmaps = perf_thread_map__nr(evlist->threads);
 
 	return nr_mmaps;
@@ -576,7 +576,7 @@ int perf_evlist__mmap_ops(struct perf_evlist *evlist,
 			  struct perf_mmap_param *mp)
 {
 	struct perf_evsel *evsel;
-	const struct perf_cpu_map *cpus = evlist->cpus;
+	const struct perf_cpu_map *cpus = evlist->user_requested_cpus;
 	const struct perf_thread_map *threads = evlist->threads;
 
 	if (!ops || !ops->get || !ops->mmap)

tools/lib/perf/include/internal/evlist.h

@@ -19,7 +19,12 @@ struct perf_evlist {
 	int			 nr_entries;
 	int			 nr_groups;
 	bool			 has_user_cpus;
-	struct perf_cpu_map	*cpus;
+	/**
+	 * The cpus passed from the command line or all online CPUs by
+	 * default.
+	 */
+	struct perf_cpu_map	*user_requested_cpus;
+	/** The union of all evsel cpu maps. */
 	struct perf_cpu_map	*all_cpus;
 	struct perf_thread_map	*threads;
 	int			 nr_mmaps;

tools/perf/arch/arm/util/cs-etm.c

@@ -199,7 +199,7 @@ static int cs_etm_set_option(struct auxtrace_record *itr,
 			     struct evsel *evsel, u32 option)
 {
 	int i, err = -EINVAL;
-	struct perf_cpu_map *event_cpus = evsel->evlist->core.cpus;
+	struct perf_cpu_map *event_cpus = evsel->evlist->core.user_requested_cpus;
 	struct perf_cpu_map *online_cpus = perf_cpu_map__new(NULL);
 
 	/* Set option of each CPU we have */
@@ -299,7 +299,7 @@ static int cs_etm_recording_options(struct auxtrace_record *itr,
 				container_of(itr, struct cs_etm_recording, itr);
 	struct perf_pmu *cs_etm_pmu = ptr->cs_etm_pmu;
 	struct evsel *evsel, *cs_etm_evsel = NULL;
-	struct perf_cpu_map *cpus = evlist->core.cpus;
+	struct perf_cpu_map *cpus = evlist->core.user_requested_cpus;
 	bool privileged = perf_event_paranoid_check(-1);
 	int err = 0;
 
@@ -522,7 +522,7 @@ cs_etm_info_priv_size(struct auxtrace_record *itr __maybe_unused,
 {
 	int i;
 	int etmv3 = 0, etmv4 = 0, ete = 0;
-	struct perf_cpu_map *event_cpus = evlist->core.cpus;
+	struct perf_cpu_map *event_cpus = evlist->core.user_requested_cpus;
 	struct perf_cpu_map *online_cpus = perf_cpu_map__new(NULL);
 
 	/* cpu map is not empty, we have specific CPUs to work with */
@@ -713,7 +713,7 @@ static int cs_etm_info_fill(struct auxtrace_record *itr,
 	u32 offset;
 	u64 nr_cpu, type;
 	struct perf_cpu_map *cpu_map;
-	struct perf_cpu_map *event_cpus = session->evlist->core.cpus;
+	struct perf_cpu_map *event_cpus = session->evlist->core.user_requested_cpus;
 	struct perf_cpu_map *online_cpus = perf_cpu_map__new(NULL);
 	struct cs_etm_recording *ptr =
 			container_of(itr, struct cs_etm_recording, itr);

tools/perf/arch/arm64/util/arm-spe.c

@@ -144,7 +144,7 @@ static int arm_spe_recording_options(struct auxtrace_record *itr,
 			container_of(itr, struct arm_spe_recording, itr);
 	struct perf_pmu *arm_spe_pmu = sper->arm_spe_pmu;
 	struct evsel *evsel, *arm_spe_evsel = NULL;
-	struct perf_cpu_map *cpus = evlist->core.cpus;
+	struct perf_cpu_map *cpus = evlist->core.user_requested_cpus;
 	bool privileged = perf_event_paranoid_check(-1);
 	struct evsel *tracking_evsel;
 	int err;

tools/perf/arch/x86/util/intel-bts.c

@@ -110,7 +110,7 @@ static int intel_bts_recording_options(struct auxtrace_record *itr,
 			container_of(itr, struct intel_bts_recording, itr);
 	struct perf_pmu *intel_bts_pmu = btsr->intel_bts_pmu;
 	struct evsel *evsel, *intel_bts_evsel = NULL;
-	const struct perf_cpu_map *cpus = evlist->core.cpus;
+	const struct perf_cpu_map *cpus = evlist->core.user_requested_cpus;
 	bool privileged = perf_event_paranoid_check(-1);
 
 	if (opts->auxtrace_sample_mode) {

tools/perf/arch/x86/util/intel-pt.c

@@ -382,7 +382,7 @@ static int intel_pt_info_fill(struct auxtrace_record *itr,
 			ui__warning("Intel Processor Trace: TSC not available\n");
 	}
 
-	per_cpu_mmaps = !perf_cpu_map__empty(session->evlist->core.cpus);
+	per_cpu_mmaps = !perf_cpu_map__empty(session->evlist->core.user_requested_cpus);
 
 	auxtrace_info->type = PERF_AUXTRACE_INTEL_PT;
 	auxtrace_info->priv[INTEL_PT_PMU_TYPE] = intel_pt_pmu->type;
@@ -632,7 +632,7 @@ static int intel_pt_recording_options(struct auxtrace_record *itr,
 	struct perf_pmu *intel_pt_pmu = ptr->intel_pt_pmu;
 	bool have_timing_info, need_immediate = false;
 	struct evsel *evsel, *intel_pt_evsel = NULL;
-	const struct perf_cpu_map *cpus = evlist->core.cpus;
+	const struct perf_cpu_map *cpus = evlist->core.user_requested_cpus;
 	bool privileged = perf_event_paranoid_check(-1);
 	u64 tsc_bit;
 	int err;

tools/perf/bench/evlist-open-close.c

@@ -151,7 +151,7 @@ static int bench_evlist_open_close__run(char *evstr)
 
 	init_stats(&time_stats);
 
-	printf("  Number of cpus:\t%d\n", perf_cpu_map__nr(evlist->core.cpus));
+	printf("  Number of cpus:\t%d\n", perf_cpu_map__nr(evlist->core.user_requested_cpus));
 	printf("  Number of threads:\t%d\n", evlist->core.threads->nr);
 	printf("  Number of events:\t%d (%d fds)\n",
 		evlist->core.nr_entries, evlist__count_evsel_fds(evlist));

tools/perf/builtin-ftrace.c

@@ -301,7 +301,7 @@ static int set_tracing_cpumask(struct perf_cpu_map *cpumap)
 
 static int set_tracing_cpu(struct perf_ftrace *ftrace)
 {
-	struct perf_cpu_map *cpumap = ftrace->evlist->core.cpus;
+	struct perf_cpu_map *cpumap = ftrace->evlist->core.user_requested_cpus;
 
 	if (!target__has_cpu(&ftrace->target))
 		return 0;

tools/perf/builtin-record.c

@@ -987,7 +987,7 @@ static int record__thread_data_init_maps(struct record_thread *thread_data, stru
 	int m, tm, nr_mmaps = evlist->core.nr_mmaps;
 	struct mmap *mmap = evlist->mmap;
 	struct mmap *overwrite_mmap = evlist->overwrite_mmap;
-	struct perf_cpu_map *cpus = evlist->core.cpus;
+	struct perf_cpu_map *cpus = evlist->core.user_requested_cpus;
 
 	thread_data->nr_mmaps = bitmap_weight(thread_data->mask->maps.bits,
 					      thread_data->mask->maps.nbits);
@@ -1881,7 +1881,7 @@ static int record__synthesize(struct record *rec, bool tail)
 		return err;
 	}
 
-	err = perf_event__synthesize_cpu_map(&rec->tool, rec->evlist->core.cpus,
+	err = perf_event__synthesize_cpu_map(&rec->tool, rec->evlist->core.user_requested_cpus,
 					     process_synthesized_event, NULL);
 	if (err < 0) {
 		pr_err("Couldn't synthesize cpu map.\n");
@@ -3675,7 +3675,7 @@ static int record__init_thread_default_masks(struct record *rec, struct perf_cpu
 static int record__init_thread_masks(struct record *rec)
 {
 	int ret = 0;
-	struct perf_cpu_map *cpus = rec->evlist->core.cpus;
+	struct perf_cpu_map *cpus = rec->evlist->core.user_requested_cpus;
 
 	if (!record__threads_enabled(rec))
 		return record__init_thread_default_masks(rec, cpus);

tools/perf/builtin-stat.c

@@ -804,7 +804,7 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx)
 	if (group)
 		evlist__set_leader(evsel_list);
 
-	if (!cpu_map__is_dummy(evsel_list->core.cpus)) {
+	if (!cpu_map__is_dummy(evsel_list->core.user_requested_cpus)) {
 		if (affinity__setup(&saved_affinity) < 0)
 			return -1;
 		affinity = &saved_affinity;
@@ -1458,7 +1458,7 @@ static int perf_stat_init_aggr_mode(void)
 	aggr_cpu_id_get_t get_id = aggr_mode__get_aggr(stat_config.aggr_mode);
 
 	if (get_id) {
-		stat_config.aggr_map = cpu_aggr_map__new(evsel_list->core.cpus,
+		stat_config.aggr_map = cpu_aggr_map__new(evsel_list->core.user_requested_cpus,
 							 get_id, /*data=*/NULL);
 		if (!stat_config.aggr_map) {
 			pr_err("cannot build %s map", aggr_mode__string[stat_config.aggr_mode]);
@@ -1472,8 +1472,8 @@ static int perf_stat_init_aggr_mode(void)
 	 * taking the highest cpu number to be the size of
 	 * the aggregation translate cpumap.
 	 */
-	if (evsel_list->core.cpus)
-		nr = perf_cpu_map__max(evsel_list->core.cpus).cpu;
+	if (evsel_list->core.user_requested_cpus)
+		nr = perf_cpu_map__max(evsel_list->core.user_requested_cpus).cpu;
 	else
 		nr = 0;
 	stat_config.cpus_aggr_map = cpu_aggr_map__empty_new(nr + 1);
@@ -1630,7 +1630,7 @@ static int perf_stat_init_aggr_mode_file(struct perf_stat *st)
 	if (!get_id)
 		return 0;
 
-	stat_config.aggr_map = cpu_aggr_map__new(evsel_list->core.cpus, get_id, env);
+	stat_config.aggr_map = cpu_aggr_map__new(evsel_list->core.user_requested_cpus, get_id, env);
 	if (!stat_config.aggr_map) {
 		pr_err("cannot build %s map", aggr_mode__string[stat_config.aggr_mode]);
 		return -1;