xref: /OK3568_Linux_fs/kernel/tools/lib/perf/Documentation/examples/sampling.c (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun #include <linux/perf_event.h>
2*4882a593Smuzhiyun #include <perf/evlist.h>
3*4882a593Smuzhiyun #include <perf/evsel.h>
4*4882a593Smuzhiyun #include <perf/cpumap.h>
5*4882a593Smuzhiyun #include <perf/threadmap.h>
6*4882a593Smuzhiyun #include <perf/mmap.h>
7*4882a593Smuzhiyun #include <perf/core.h>
8*4882a593Smuzhiyun #include <perf/event.h>
9*4882a593Smuzhiyun #include <stdio.h>
10*4882a593Smuzhiyun #include <unistd.h>
11*4882a593Smuzhiyun 
libperf_print(enum libperf_print_level level,const char * fmt,va_list ap)12*4882a593Smuzhiyun static int libperf_print(enum libperf_print_level level,
13*4882a593Smuzhiyun                          const char *fmt, va_list ap)
14*4882a593Smuzhiyun {
15*4882a593Smuzhiyun 	return vfprintf(stderr, fmt, ap);
16*4882a593Smuzhiyun }
17*4882a593Smuzhiyun 
18*4882a593Smuzhiyun union u64_swap {
19*4882a593Smuzhiyun 	__u64 val64;
20*4882a593Smuzhiyun 	__u32 val32[2];
21*4882a593Smuzhiyun };
22*4882a593Smuzhiyun 
main(int argc,char ** argv)23*4882a593Smuzhiyun int main(int argc, char **argv)
24*4882a593Smuzhiyun {
25*4882a593Smuzhiyun 	struct perf_evlist *evlist;
26*4882a593Smuzhiyun 	struct perf_evsel *evsel;
27*4882a593Smuzhiyun 	struct perf_mmap *map;
28*4882a593Smuzhiyun 	struct perf_cpu_map *cpus;
29*4882a593Smuzhiyun 	struct perf_event_attr attr = {
30*4882a593Smuzhiyun 		.type        = PERF_TYPE_HARDWARE,
31*4882a593Smuzhiyun 		.config      = PERF_COUNT_HW_CPU_CYCLES,
32*4882a593Smuzhiyun 		.disabled    = 1,
33*4882a593Smuzhiyun 		.freq        = 1,
34*4882a593Smuzhiyun 		.sample_freq = 10,
35*4882a593Smuzhiyun 		.sample_type = PERF_SAMPLE_IP|PERF_SAMPLE_TID|PERF_SAMPLE_CPU|PERF_SAMPLE_PERIOD,
36*4882a593Smuzhiyun 	};
37*4882a593Smuzhiyun 	int err = -1;
38*4882a593Smuzhiyun 	union perf_event *event;
39*4882a593Smuzhiyun 
40*4882a593Smuzhiyun 	libperf_init(libperf_print);
41*4882a593Smuzhiyun 
42*4882a593Smuzhiyun 	cpus = perf_cpu_map__new(NULL);
43*4882a593Smuzhiyun 	if (!cpus) {
44*4882a593Smuzhiyun 		fprintf(stderr, "failed to create cpus\n");
45*4882a593Smuzhiyun 		return -1;
46*4882a593Smuzhiyun 	}
47*4882a593Smuzhiyun 
48*4882a593Smuzhiyun 	evlist = perf_evlist__new();
49*4882a593Smuzhiyun 	if (!evlist) {
50*4882a593Smuzhiyun 		fprintf(stderr, "failed to create evlist\n");
51*4882a593Smuzhiyun 		goto out_cpus;
52*4882a593Smuzhiyun 	}
53*4882a593Smuzhiyun 
54*4882a593Smuzhiyun 	evsel = perf_evsel__new(&attr);
55*4882a593Smuzhiyun 	if (!evsel) {
56*4882a593Smuzhiyun 		fprintf(stderr, "failed to create cycles\n");
57*4882a593Smuzhiyun 		goto out_cpus;
58*4882a593Smuzhiyun 	}
59*4882a593Smuzhiyun 
60*4882a593Smuzhiyun 	perf_evlist__add(evlist, evsel);
61*4882a593Smuzhiyun 
62*4882a593Smuzhiyun 	perf_evlist__set_maps(evlist, cpus, NULL);
63*4882a593Smuzhiyun 
64*4882a593Smuzhiyun 	err = perf_evlist__open(evlist);
65*4882a593Smuzhiyun 	if (err) {
66*4882a593Smuzhiyun 		fprintf(stderr, "failed to open evlist\n");
67*4882a593Smuzhiyun 		goto out_evlist;
68*4882a593Smuzhiyun 	}
69*4882a593Smuzhiyun 
70*4882a593Smuzhiyun 	err = perf_evlist__mmap(evlist, 4);
71*4882a593Smuzhiyun 	if (err) {
72*4882a593Smuzhiyun 		fprintf(stderr, "failed to mmap evlist\n");
73*4882a593Smuzhiyun 		goto out_evlist;
74*4882a593Smuzhiyun 	}
75*4882a593Smuzhiyun 
76*4882a593Smuzhiyun 	perf_evlist__enable(evlist);
77*4882a593Smuzhiyun 	sleep(3);
78*4882a593Smuzhiyun 	perf_evlist__disable(evlist);
79*4882a593Smuzhiyun 
80*4882a593Smuzhiyun 	perf_evlist__for_each_mmap(evlist, map, false) {
81*4882a593Smuzhiyun 		if (perf_mmap__read_init(map) < 0)
82*4882a593Smuzhiyun 			continue;
83*4882a593Smuzhiyun 
84*4882a593Smuzhiyun 		while ((event = perf_mmap__read_event(map)) != NULL) {
85*4882a593Smuzhiyun 			int cpu, pid, tid;
86*4882a593Smuzhiyun 			__u64 ip, period, *array;
87*4882a593Smuzhiyun 			union u64_swap u;
88*4882a593Smuzhiyun 
89*4882a593Smuzhiyun 			array = event->sample.array;
90*4882a593Smuzhiyun 
91*4882a593Smuzhiyun 			ip = *array;
92*4882a593Smuzhiyun 			array++;
93*4882a593Smuzhiyun 
94*4882a593Smuzhiyun 			u.val64 = *array;
95*4882a593Smuzhiyun 			pid = u.val32[0];
96*4882a593Smuzhiyun 			tid = u.val32[1];
97*4882a593Smuzhiyun 			array++;
98*4882a593Smuzhiyun 
99*4882a593Smuzhiyun 			u.val64 = *array;
100*4882a593Smuzhiyun 			cpu = u.val32[0];
101*4882a593Smuzhiyun 			array++;
102*4882a593Smuzhiyun 
103*4882a593Smuzhiyun 			period = *array;
104*4882a593Smuzhiyun 
105*4882a593Smuzhiyun 			fprintf(stdout, "cpu %3d, pid %6d, tid %6d, ip %20llx, period %20llu\n",
106*4882a593Smuzhiyun 				cpu, pid, tid, ip, period);
107*4882a593Smuzhiyun 
108*4882a593Smuzhiyun 			perf_mmap__consume(map);
109*4882a593Smuzhiyun 		}
110*4882a593Smuzhiyun 
111*4882a593Smuzhiyun 		perf_mmap__read_done(map);
112*4882a593Smuzhiyun 	}
113*4882a593Smuzhiyun 
114*4882a593Smuzhiyun out_evlist:
115*4882a593Smuzhiyun 	perf_evlist__delete(evlist);
116*4882a593Smuzhiyun out_cpus:
117*4882a593Smuzhiyun 	perf_cpu_map__put(cpus);
118*4882a593Smuzhiyun 	return err;
119*4882a593Smuzhiyun }
120