perf_event__synthesize_thread_map2
err = perf_event__synthesize_thread_map2(&rec->tool, rec->evlist->core.threads,
!perf_event__synthesize_thread_map2(NULL, threads, process_event, NULL));
err = perf_event__synthesize_thread_map2(tool, evlist->core.threads, process, NULL);
int perf_event__synthesize_thread_map2(const struct perf_tool *tool, struct perf_thread_map *threads, perf_event__handler_t process, struct machine *machine);