Commit e98d5b16 authored by Tejun Heo's avatar Tejun Heo
Browse files

workqueue: make workqueue_lock irq-safe 



workqueue_lock will be used to synchronize areas which require
irq-safety and there isn't much benefit in keeping it not irq-safe.
Make it irq-safe.

This patch doesn't introduce any visible behavior changes.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Reviewed-by: default avatarLai Jiangshan <laijs@cn.fujitsu.com>
parent 6183c009

kernel/workqueue.c

+22 −22
Original line number Original line Diff line number Diff line
@@ -2715,10 +2715,10 @@ void drain_workqueue(struct workqueue_struct *wq) 
	 * hotter than drain_workqueue() and already looks at @wq->flags.

	 * hotter than drain_workqueue() and already looks at @wq->flags.

	 * Use WQ_DRAINING so that queue doesn't have to check nr_drainers.

	 * Use WQ_DRAINING so that queue doesn't have to check nr_drainers.

	 */

	 */

	spin_lock(&workqueue_lock);

	spin_lock_irq(&workqueue_lock);

	if (!wq->nr_drainers++)

	if (!wq->nr_drainers++)

		wq->flags |= WQ_DRAINING;

		wq->flags |= WQ_DRAINING;

	spin_unlock(&workqueue_lock);

	spin_unlock_irq(&workqueue_lock);

reflush:

reflush:

	flush_workqueue(wq);

	flush_workqueue(wq);
@@ -2740,10 +2740,10 @@ void drain_workqueue(struct workqueue_struct *wq) 
		goto reflush;

		goto reflush;

	}

	}





	spin_lock(&workqueue_lock);

	spin_lock_irq(&workqueue_lock);

	if (!--wq->nr_drainers)

	if (!--wq->nr_drainers)

		wq->flags &= ~WQ_DRAINING;

		wq->flags &= ~WQ_DRAINING;

	spin_unlock(&workqueue_lock);

	spin_unlock_irq(&workqueue_lock);

}

}

EXPORT_SYMBOL_GPL(drain_workqueue);

EXPORT_SYMBOL_GPL(drain_workqueue);
@@ -3233,7 +3233,7 @@ struct workqueue_struct *__alloc_workqueue_key(const char *fmt, 
	 * list.  Grab it, set max_active accordingly and add the new

	 * list.  Grab it, set max_active accordingly and add the new

	 * workqueue to workqueues list.

	 * workqueue to workqueues list.

	 */

	 */

	spin_lock(&workqueue_lock);

	spin_lock_irq(&workqueue_lock);





	if (workqueue_freezing && wq->flags & WQ_FREEZABLE)

	if (workqueue_freezing && wq->flags & WQ_FREEZABLE)

		for_each_pwq_cpu(cpu, wq)

		for_each_pwq_cpu(cpu, wq)
@@ -3241,7 +3241,7 @@ struct workqueue_struct *__alloc_workqueue_key(const char *fmt, 




	list_add(&wq->list, &workqueues);

	list_add(&wq->list, &workqueues);





	spin_unlock(&workqueue_lock);

	spin_unlock_irq(&workqueue_lock);





	return wq;

	return wq;

err:

err:
@@ -3285,9 +3285,9 @@ void destroy_workqueue(struct workqueue_struct *wq) 
	 * wq list is used to freeze wq, remove from list after

	 * wq list is used to freeze wq, remove from list after

	 * flushing is complete in case freeze races us.

	 * flushing is complete in case freeze races us.

	 */

	 */

	spin_lock(&workqueue_lock);

	spin_lock_irq(&workqueue_lock);

	list_del(&wq->list);

	list_del(&wq->list);

	spin_unlock(&workqueue_lock);

	spin_unlock_irq(&workqueue_lock);





	if (wq->flags & WQ_RESCUER) {

	if (wq->flags & WQ_RESCUER) {

		kthread_stop(wq->rescuer->task);

		kthread_stop(wq->rescuer->task);
@@ -3336,7 +3336,7 @@ void workqueue_set_max_active(struct workqueue_struct *wq, int max_active) 




	max_active = wq_clamp_max_active(max_active, wq->flags, wq->name);

	max_active = wq_clamp_max_active(max_active, wq->flags, wq->name);





	spin_lock(&workqueue_lock);

	spin_lock_irq(&workqueue_lock);





	wq->saved_max_active = max_active;

	wq->saved_max_active = max_active;
@@ -3344,16 +3344,16 @@ void workqueue_set_max_active(struct workqueue_struct *wq, int max_active) 
		struct pool_workqueue *pwq = get_pwq(cpu, wq);

		struct pool_workqueue *pwq = get_pwq(cpu, wq);

		struct worker_pool *pool = pwq->pool;

		struct worker_pool *pool = pwq->pool;





		spin_lock_irq(&pool->lock);

		spin_lock(&pool->lock);





		if (!(wq->flags & WQ_FREEZABLE) ||

		if (!(wq->flags & WQ_FREEZABLE) ||

		    !(pool->flags & POOL_FREEZING))

		    !(pool->flags & POOL_FREEZING))

			pwq_set_max_active(pwq, max_active);

			pwq_set_max_active(pwq, max_active);





		spin_unlock_irq(&pool->lock);

		spin_unlock(&pool->lock);

	}

	}





	spin_unlock(&workqueue_lock);

	spin_unlock_irq(&workqueue_lock);

}

}

EXPORT_SYMBOL_GPL(workqueue_set_max_active);

EXPORT_SYMBOL_GPL(workqueue_set_max_active);
@@ -3599,7 +3599,7 @@ void freeze_workqueues_begin(void) 
{

{

	unsigned int cpu;

	unsigned int cpu;





	spin_lock(&workqueue_lock);

	spin_lock_irq(&workqueue_lock);





	WARN_ON_ONCE(workqueue_freezing);

	WARN_ON_ONCE(workqueue_freezing);

	workqueue_freezing = true;

	workqueue_freezing = true;
@@ -3609,7 +3609,7 @@ void freeze_workqueues_begin(void) 
		struct workqueue_struct *wq;

		struct workqueue_struct *wq;





		for_each_std_worker_pool(pool, cpu) {

		for_each_std_worker_pool(pool, cpu) {

			spin_lock_irq(&pool->lock);

			spin_lock(&pool->lock);





			WARN_ON_ONCE(pool->flags & POOL_FREEZING);

			WARN_ON_ONCE(pool->flags & POOL_FREEZING);

			pool->flags |= POOL_FREEZING;

			pool->flags |= POOL_FREEZING;
@@ -3622,11 +3622,11 @@ void freeze_workqueues_begin(void) 
					pwq->max_active = 0;

					pwq->max_active = 0;

			}

			}





			spin_unlock_irq(&pool->lock);

			spin_unlock(&pool->lock);

		}

		}

	}

	}





	spin_unlock(&workqueue_lock);

	spin_unlock_irq(&workqueue_lock);

}

}





/**

/**
@@ -3647,7 +3647,7 @@ bool freeze_workqueues_busy(void) 
	unsigned int cpu;

	unsigned int cpu;

	bool busy = false;

	bool busy = false;





	spin_lock(&workqueue_lock);

	spin_lock_irq(&workqueue_lock);





	WARN_ON_ONCE(!workqueue_freezing);

	WARN_ON_ONCE(!workqueue_freezing);
@@ -3671,7 +3671,7 @@ bool freeze_workqueues_busy(void) 
		}

		}

	}

	}

out_unlock:

out_unlock:

	spin_unlock(&workqueue_lock);

	spin_unlock_irq(&workqueue_lock);

	return busy;

	return busy;

}

}
@@ -3688,7 +3688,7 @@ void thaw_workqueues(void) 
{

{

	unsigned int cpu;

	unsigned int cpu;





	spin_lock(&workqueue_lock);

	spin_lock_irq(&workqueue_lock);





	if (!workqueue_freezing)

	if (!workqueue_freezing)

		goto out_unlock;

		goto out_unlock;
@@ -3698,7 +3698,7 @@ void thaw_workqueues(void) 
		struct workqueue_struct *wq;

		struct workqueue_struct *wq;





		for_each_std_worker_pool(pool, cpu) {

		for_each_std_worker_pool(pool, cpu) {

			spin_lock_irq(&pool->lock);

			spin_lock(&pool->lock);





			WARN_ON_ONCE(!(pool->flags & POOL_FREEZING));

			WARN_ON_ONCE(!(pool->flags & POOL_FREEZING));

			pool->flags &= ~POOL_FREEZING;

			pool->flags &= ~POOL_FREEZING;
@@ -3716,13 +3716,13 @@ void thaw_workqueues(void) 




			wake_up_worker(pool);

			wake_up_worker(pool);





			spin_unlock_irq(&pool->lock);

			spin_unlock(&pool->lock);

		}

		}

	}

	}





	workqueue_freezing = false;

	workqueue_freezing = false;

out_unlock:

out_unlock:

	spin_unlock(&workqueue_lock);

	spin_unlock_irq(&workqueue_lock);

}

}

#endif /* CONFIG_FREEZER */

#endif /* CONFIG_FREEZER */