1#include <linux/perf_event.h>
  2#include <perf/evlist.h>
  3#include <perf/evsel.h>
  4#include <perf/cpumap.h>
  5#include <perf/threadmap.h>
  6#include <perf/mmap.h>
  7#include <perf/core.h>
  8#include <perf/event.h>
  9#include <stdio.h>
 10#include <unistd.h>
 11
 12static int libperf_print(enum libperf_print_level level,
 13                         const char *fmt, va_list ap)
 14{
 15	return vfprintf(stderr, fmt, ap);
 16}
 17
 18union u64_swap {
 19	__u64 val64;
 20	__u32 val32[2];
 21};
 22
 23int main(int argc, char **argv)
 24{
 25	struct perf_evlist *evlist;
 26	struct perf_evsel *evsel;
 27	struct perf_mmap *map;
 28	struct perf_cpu_map *cpus;
 29	struct perf_event_attr attr = {
 30		.type        = PERF_TYPE_HARDWARE,
 31		.config      = PERF_COUNT_HW_CPU_CYCLES,
 32		.disabled    = 1,
 33		.freq        = 1,
 34		.sample_freq = 10,
 35		.sample_type = PERF_SAMPLE_IP|PERF_SAMPLE_TID|PERF_SAMPLE_CPU|PERF_SAMPLE_PERIOD,
 36	};
 37	int err = -1;
 38	union perf_event *event;
 39
 40	libperf_init(libperf_print);
 41
 42	cpus = perf_cpu_map__new_online_cpus();
 43	if (!cpus) {
 44		fprintf(stderr, "failed to create cpus\n");
 45		return -1;
 46	}
 47
 48	evlist = perf_evlist__new();
 49	if (!evlist) {
 50		fprintf(stderr, "failed to create evlist\n");
 51		goto out_cpus;
 52	}
 53
 54	evsel = perf_evsel__new(&attr);
 55	if (!evsel) {
 56		fprintf(stderr, "failed to create cycles\n");
 57		goto out_cpus;
 58	}
 59
 60	perf_evlist__add(evlist, evsel);
 61
 62	perf_evlist__set_maps(evlist, cpus, NULL);
 63
 64	err = perf_evlist__open(evlist);
 65	if (err) {
 66		fprintf(stderr, "failed to open evlist\n");
 67		goto out_evlist;
 68	}
 69
 70	err = perf_evlist__mmap(evlist, 4);
 71	if (err) {
 72		fprintf(stderr, "failed to mmap evlist\n");
 73		goto out_evlist;
 74	}
 75
 76	perf_evlist__enable(evlist);
 77	sleep(3);
 78	perf_evlist__disable(evlist);
 79
 80	perf_evlist__for_each_mmap(evlist, map, false) {
 81		if (perf_mmap__read_init(map) < 0)
 82			continue;
 83
 84		while ((event = perf_mmap__read_event(map)) != NULL) {
 85			int cpu, pid, tid;
 86			__u64 ip, period, *array;
 87			union u64_swap u;
 88
 89			array = event->sample.array;
 90
 91			ip = *array;
 92			array++;
 93
 94			u.val64 = *array;
 95			pid = u.val32[0];
 96			tid = u.val32[1];
 97			array++;
 98
 99			u.val64 = *array;
100			cpu = u.val32[0];
101			array++;
102
103			period = *array;
104
105			fprintf(stdout, "cpu %3d, pid %6d, tid %6d, ip %20llx, period %20llu\n",
106				cpu, pid, tid, ip, period);
107
108			perf_mmap__consume(map);
109		}
110
111		perf_mmap__read_done(map);
112	}
113
114out_evlist:
115	perf_evlist__delete(evlist);
116out_cpus:
117	perf_cpu_map__put(cpus);
118	return err;
119}