module: Replace over-engineered nested sleep (9cc019b8) · Commits · 戴 / test

kernel/module.c

+8 −28

Original line number	Diff line number	Diff line
		@@ -2984,6 +2984,12 @@ static bool finished_loading(const char *name)
		struct module *mod;
		bool ret;

		/*
		* The module_mutex should not be a heavily contended lock;
		* if we get the occasional sleep here, we'll go an extra iteration
		* in the wait_event_interruptible(), which is harmless.
		*/
		sched_annotate_sleep();
		mutex_lock(&module_mutex);
		mod = find_module_all(name, strlen(name), true);
		ret = !mod \|\| mod->state == MODULE_STATE_LIVE
		@@ -3125,32 +3131,6 @@ static int may_init_module(void)
		return 0;
		}

		/*
		* Can't use wait_event_interruptible() because our condition
		* 'finished_loading()' contains a blocking primitive itself (mutex_lock).
		*/
		static int wait_finished_loading(struct module *mod)
		{
		DEFINE_WAIT_FUNC(wait, woken_wake_function);
		int ret = 0;

		add_wait_queue(&module_wq, &wait);
		for (;;) {
		if (finished_loading(mod->name))
		break;

		if (signal_pending(current)) {
		ret = -ERESTARTSYS;
		break;
		}

		wait_woken(&wait, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
		}
		remove_wait_queue(&module_wq, &wait);

		return ret;
		}

		/*
		* We try to place it in the list now to make sure it's unique before
		* we dedicate too many resources. In particular, temporary percpu
		@@ -3171,8 +3151,8 @@ again:
		\|\| old->state == MODULE_STATE_UNFORMED) {
		/* Wait in case it fails to load. */
		mutex_unlock(&module_mutex);

		err = wait_finished_loading(mod);
		err = wait_event_interruptible(module_wq,
		finished_loading(mod->name));
		if (err)
		goto out_unlocked;
		goto again;