perf_thread_map__idx
LIBPERF_API int perf_thread_map__idx(struct perf_thread_map *map, pid_t pid);
thread_map_idx = perf_thread_map__idx(evsel->core.threads, sample->tid);
thread_idx = perf_thread_map__idx(evsel->core.threads, thread);
thread_idx = perf_thread_map__idx(pos2->core.threads, thread);