perf_event_exit_event
perf_event_exit_event(event, ctx, ctx->task, DETACH_REVOKE);
perf_event_exit_event(child_event, ctx, exit ? task : NULL, 0);
static void perf_event_exit_event(struct perf_event *event,
perf_event_exit_event(event, ctx, ctx->task, DETACH_GROUP);