#include <linux/perf_event.h>#include <perf/evlist.h>#include <perf/evsel.h>#include <perf/cpumap.h>#include <perf/threadmap.h>#include <perf/mmap.h>#include <perf/core.h>#include <perf/event.h>#include <stdio.h>#include <unistd.h> static int libperf_print(enum libperf_print_level level,                         const char *fmt, va_list ap){	return vfprintf(stderr, fmt, ap);} union u64_swap {	__u64 val64;	__u32 val32[2];}; int main(int argc, char **argv){	struct perf_evlist *evlist;	struct perf_evsel *evsel;	struct perf_mmap *map;	struct perf_cpu_map *cpus;	struct perf_event_attr attr = {		.type        = PERF_TYPE_HARDWARE,		.config      = PERF_COUNT_HW_CPU_CYCLES,		.disabled    = 1,		.freq        = 1,		.sample_freq = 10,		.sample_type = PERF_SAMPLE_IP|PERF_SAMPLE_TID|PERF_SAMPLE_CPU|PERF_SAMPLE_PERIOD,	};	int err = -1;	union perf_event *event; 	libperf_init(libperf_print); 	cpus = perf_cpu_map__new_online_cpus();	if (!cpus) {		fprintf(stderr, "failed to create cpus\n");		return -1;	} 	evlist = perf_evlist__new();	if (!evlist) {		fprintf(stderr, "failed to create evlist\n");		goto out_cpus;	} 	evsel = perf_evsel__new(&attr);	if (!evsel) {		fprintf(stderr, "failed to create cycles\n");		goto out_cpus;	} 	perf_evlist__add(evlist, evsel); 	perf_evlist__set_maps(evlist, cpus, NULL); 	err = perf_evlist__open(evlist);	if (err) {		fprintf(stderr, "failed to open evlist\n");		goto out_evlist;	} 	err = perf_evlist__mmap(evlist, 4);	if (err) {		fprintf(stderr, "failed to mmap evlist\n");		goto out_evlist;	} 	perf_evlist__enable(evlist);	sleep(3);	perf_evlist__disable(evlist); 	perf_evlist__for_each_mmap(evlist, map, false) {		if (perf_mmap__read_init(map) < 0)			continue; 		while ((event = perf_mmap__read_event(map)) != NULL) {			int cpu, pid, tid;			__u64 ip, period, *array;			union u64_swap u; 			array = event->sample.array; 			ip = *array;			array++; 			u.val64 = *array;			pid = u.val32[0];			tid = u.val32[1];			array++; 			u.val64 = *array;			cpu = u.val32[0];			array++; 			period = *array; 			fprintf(stdout, "cpu %3d, pid %6d, tid %6d, ip %20llx, period %20llu\n",				cpu, pid, tid, ip, period); 			perf_mmap__consume(map);		} 		perf_mmap__read_done(map);	} out_evlist:	perf_evlist__delete(evlist);out_cpus:	perf_cpu_map__put(cpus);	return err;}