Commit 175c8523 authored by Ian Rogers's avatar Ian Rogers Committed by Namhyung Kim
Browse files

perf tool_pmu: Allow num_cpus(_online) to be specific to a cpumask 



For hybrid metrics it is useful to know the number of p-core or e-core
CPUs. If a cpumask is specified for the num_cpus or num_cpus_online
tool events, compute the value relative to the given mask rather than
for the full system.

```
$ sudo /tmp/perf/perf stat -e 'tool/num_cpus/,tool/num_cpus,cpu=cpu_core/,
  tool/num_cpus,cpu=cpu_atom/,tool/num_cpus_online/,tool/num_cpus_online,
  cpu=cpu_core/,tool/num_cpus_online,cpu=cpu_atom/' true

 Performance counter stats for 'true':

                28      tool/num_cpus/
                16      tool/num_cpus,cpu=cpu_core/
                12      tool/num_cpus,cpu=cpu_atom/
                28      tool/num_cpus_online/
                16      tool/num_cpus_online,cpu=cpu_core/
                12      tool/num_cpus_online,cpu=cpu_atom/

       0.000767205 seconds time elapsed

       0.000938000 seconds user
       0.000000000 seconds sys
```

Reviewed-by: default avatarThomas Falcon <thomas.falcon@intel.com>
Signed-off-by: default avatarIan Rogers <irogers@google.com>
Tested-by: default avatarJames Clark <james.clark@linaro.org>
Link: https://lore.kernel.org/r/20250719030517.1990983-6-irogers@google.com


Signed-off-by: default avatarNamhyung Kim <namhyung@kernel.org>
parent bd741d80

tools/perf/util/expr.c

+1 −1
Original line number Diff line number Diff line
@@ -401,7 +401,7 @@ double expr__get_literal(const char *literal, const struct expr_scanner_ctx *ctx 
	if (ev != TOOL_PMU__EVENT_NONE) {

		u64 count;



		if (tool_pmu__read_event(ev, &count))

		if (tool_pmu__read_event(ev, /*evsel=*/NULL, &count))

			result = count;

		else

			pr_err("Failure to read '%s'", literal);

tools/perf/util/tool_pmu.c

+49 −7
Original line number Diff line number Diff line
@@ -332,7 +332,7 @@ static bool has_pmem(void) 
	return has_pmem;

}



bool tool_pmu__read_event(enum tool_pmu_event ev, u64 *result)

bool tool_pmu__read_event(enum tool_pmu_event ev, struct evsel *evsel, u64 *result)

{

	const struct cpu_topology *topology;
@@ -347,19 +347,61 @@ bool tool_pmu__read_event(enum tool_pmu_event ev, u64 *result) 
		return true;



	case TOOL_PMU__EVENT_NUM_CPUS:

		if (!evsel || perf_cpu_map__is_empty(evsel->core.cpus)) {

			/* No evsel to be specific to. */

			*result = cpu__max_present_cpu().cpu;

		} else if (!perf_cpu_map__has_any_cpu(evsel->core.cpus)) {

			/* Evsel just has specific CPUs. */

			*result = perf_cpu_map__nr(evsel->core.cpus);

		} else {

			/*

			 * "Any CPU" event that can be scheduled on any CPU in

			 * the PMU's cpumask. The PMU cpumask should be saved in

			 * own_cpus. If not present fall back to max.

			 */

			if (!perf_cpu_map__is_empty(evsel->core.own_cpus))

				*result = perf_cpu_map__nr(evsel->core.own_cpus);

			else

				*result = cpu__max_present_cpu().cpu;

		}

		return true;



	case TOOL_PMU__EVENT_NUM_CPUS_ONLINE: {

		struct perf_cpu_map *online = cpu_map__online();



		if (online) {

		if (!online)

			return false;



		if (!evsel || perf_cpu_map__is_empty(evsel->core.cpus)) {

			/* No evsel to be specific to. */

			*result = perf_cpu_map__nr(online);

		} else if (!perf_cpu_map__has_any_cpu(evsel->core.cpus)) {

			/* Evsel just has specific CPUs. */

			struct perf_cpu_map *tmp =

				perf_cpu_map__intersect(online, evsel->core.cpus);



			*result = perf_cpu_map__nr(tmp);

			perf_cpu_map__put(tmp);

		} else {

			/*

			 * "Any CPU" event that can be scheduled on any CPU in

			 * the PMU's cpumask. The PMU cpumask should be saved in

			 * own_cpus, if not present then just the online cpu

			 * mask.

			 */

			if (!perf_cpu_map__is_empty(evsel->core.own_cpus)) {

				struct perf_cpu_map *tmp =

					perf_cpu_map__intersect(online, evsel->core.own_cpus);



				*result = perf_cpu_map__nr(tmp);

				perf_cpu_map__put(tmp);

			} else {

				*result = perf_cpu_map__nr(online);

			}

		}

		perf_cpu_map__put(online);

		return true;

	}

		return false;

	}

	case TOOL_PMU__EVENT_NUM_DIES:

		topology = online_topology();

		*result = topology->die_cpus_lists;
@@ -417,7 +459,7 @@ int evsel__tool_pmu_read(struct evsel *evsel, int cpu_map_idx, int thread) 
			old_count = perf_counts(evsel->prev_raw_counts, cpu_map_idx, thread);

		val = 0;

		if (cpu_map_idx == 0 && thread == 0) {

			if (!tool_pmu__read_event(ev, &val)) {

			if (!tool_pmu__read_event(ev, evsel, &val)) {

				count->lost++;

				val = 0;

			}

tools/perf/util/tool_pmu.h

+1 −1
Original line number Diff line number Diff line
@@ -34,7 +34,7 @@ enum tool_pmu_event tool_pmu__str_to_event(const char *str); 
bool tool_pmu__skip_event(const char *name);

int tool_pmu__num_skip_events(void);



bool tool_pmu__read_event(enum tool_pmu_event ev, u64 *result);

bool tool_pmu__read_event(enum tool_pmu_event ev, struct evsel *evsel, u64 *result);



u64 tool_pmu__cpu_slots_per_cycle(void);