perf sched: Factor out destroy_tasks()

Add destroy_tasks() as a counterpart of create_tasks() and put the
thread safety notations there. After join, it destroys semaphores too.

Signed-off-by: Namhyung Kim <[e-mail]>
Cc: Adrian Hunter <[e-mail]>
Cc: Ian Rogers <[e-mail]>
Cc: Ingo Molnar <[e-mail]>
Cc: Jiri Olsa <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/builtin-sched.c

···
 	}
 }
 
+static void destroy_tasks(struct perf_sched *sched)
+	UNLOCK_FUNCTION(sched->start_work_mutex)
+	UNLOCK_FUNCTION(sched->work_done_wait_mutex)
+{
+	struct task_desc *task;
+	unsigned long i;
+	int err;
+
+	mutex_unlock(&sched->start_work_mutex);
+	mutex_unlock(&sched->work_done_wait_mutex);
+	/* Get rid of threads so they won't be upset by mutex destrunction */
+	for (i = 0; i < sched->nr_tasks; i++) {
+		task = sched->tasks[i];
+		err = pthread_join(task->thread, NULL);
+		BUG_ON(err);
+		sem_destroy(&task->sleep_sem);
+		sem_destroy(&task->ready_for_work);
+		sem_destroy(&task->work_done_sem);
+	}
+}
+
 static void wait_for_tasks(struct perf_sched *sched)
 	EXCLUSIVE_LOCKS_REQUIRED(sched->work_done_wait_mutex)
 	EXCLUSIVE_LOCKS_REQUIRED(sched->start_work_mutex)
···
 		run_one_test(sched);
 
 	sched->thread_funcs_exit = true;
-	mutex_unlock(&sched->start_work_mutex);
-	mutex_unlock(&sched->work_done_wait_mutex);
+	destroy_tasks(sched);
 	return 0;
 }