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}
120