topdown.c

  1// SPDX-License-Identifier: GPL-2.0
  2#include <errno.h>
  3#include "util/evlist.h"
  4#include "util/pmu.h"
  5#include "util/pmus.h"
  6#include "util/topdown.h"
  7#include "topdown.h"
  8#include "evsel.h"
  9
 10// cmask=0, inv=0, pc=0, edge=0, umask=4, event=0
 11#define TOPDOWN_SLOTS		0x0400
 12
 13/* Check whether there is a PMU which supports the perf metrics. */
 14bool topdown_sys_has_perf_metrics(void)
 15{
 16	static bool has_perf_metrics;
 17	static bool cached;
 18	struct perf_pmu *pmu;
 19
 20	if (cached)
 21		return has_perf_metrics;
 22
 23	/*
 24	 * The perf metrics feature is a core PMU feature.
 25	 * The PERF_TYPE_RAW type is the type of a core PMU.
 26	 * The slots event is only available when the core PMU
 27	 * supports the perf metrics feature.
 28	 */
 29	pmu = perf_pmus__find_by_type(PERF_TYPE_RAW);
 30	if (pmu && perf_pmu__have_event(pmu, "slots"))
 31		has_perf_metrics = true;
 32
 33	cached = true;
 34	return has_perf_metrics;
 35}
 36
 37bool arch_is_topdown_slots(const struct evsel *evsel)
 38{
 39	return evsel->core.attr.type == PERF_TYPE_RAW &&
 40	       evsel->core.attr.config == TOPDOWN_SLOTS &&
 41	       evsel->core.attr.config1 == 0;
 42}
 43
 44bool arch_is_topdown_metrics(const struct evsel *evsel)
 45{
 46	// cmask=0, inv=0, pc=0, edge=0, umask=0x80-0x87, event=0
 47	return evsel->core.attr.type == PERF_TYPE_RAW &&
 48		(evsel->core.attr.config & 0xFFFFF8FF) == 0x8000 &&
 49		evsel->core.attr.config1 == 0;
 50}
 51
 52/*
 53 * Check whether a topdown group supports sample-read.
 54 *
 55 * Only Topdown metric supports sample-read. The slots
 56 * event must be the leader of the topdown group.
 57 */
 58bool arch_topdown_sample_read(struct evsel *leader)
 59{
 60	struct evsel *evsel;
 61
 62	if (!evsel__sys_has_perf_metrics(leader))
 63		return false;
 64
 65	if (!arch_is_topdown_slots(leader))
 66		return false;
 67
 68	/*
 69	 * If slots event as leader event but no topdown metric events
 70	 * in group, slots event should still sample as leader.
 71	 */
 72	evlist__for_each_entry(leader->evlist, evsel) {
 73		if (evsel->core.leader != leader->core.leader)
 74			continue;
 75		if (evsel != leader && arch_is_topdown_metrics(evsel))
 76			return true;
 77	}
 78
 79	return false;
 80}
 81
 82/*
 83 * Make a copy of the topdown metric event metric_event with the given index but
 84 * change its configuration to be a topdown slots event. Copying from
 85 * metric_event ensures modifiers are the same.
 86 */
 87int topdown_insert_slots_event(struct list_head *list, int idx, struct evsel *metric_event)
 88{
 89	struct evsel *evsel = evsel__new_idx(&metric_event->core.attr, idx);
 90
 91	if (!evsel)
 92		return -ENOMEM;
 93
 94	evsel->core.attr.config = TOPDOWN_SLOTS;
 95	evsel->core.cpus = perf_cpu_map__get(metric_event->core.cpus);
 96	evsel->core.pmu_cpus = perf_cpu_map__get(metric_event->core.pmu_cpus);
 97	evsel->core.is_pmu_core = true;
 98	evsel->pmu = metric_event->pmu;
 99	evsel->name = strdup("slots");
100	evsel->precise_max = metric_event->precise_max;
101	evsel->sample_read = metric_event->sample_read;
102	evsel->weak_group = metric_event->weak_group;
103	evsel->bpf_counter = metric_event->bpf_counter;
104	evsel->retire_lat = metric_event->retire_lat;
105	evsel__set_leader(evsel, evsel__leader(metric_event));
106	list_add_tail(&evsel->core.node, list);
107	return 0;
108}