perf_evsel__open
err = perf_evsel__open(evsel, evsel->cpus, evsel->threads);
LIBPERF_API int perf_evsel__open(struct perf_evsel *evsel, struct perf_cpu_map *cpus,
err = perf_evsel__open(evsel, NULL, threads);
err = perf_evsel__open(evsel, NULL, threads);
err = perf_evsel__open(evsel, NULL, threads);
err = perf_evsel__open(evsel, NULL, threads);
err = perf_evsel__open(leader, NULL, threads);
err = perf_evsel__open(member, NULL, threads);
err = perf_evsel__open(evsel, cpus, NULL);
err = perf_evsel__open(evsel, NULL, threads);
err = perf_evsel__open(evsel, NULL, threads);