Commit 13b1d625 authored Jul 22, 2014 by Lai Jiangshan Committed by Tejun Heo Jul 22, 2014

workqueue: move rescuer pool detachment to the end



In 51697d39 ("workqueue: use generic attach/detach routine for
rescuers"), The rescuer detaches itself from the pool before put_pwq()
so that the put_unbound_pool() will not destroy the rescuer-attached
pool.

It is unnecessary.  worker_detach_from_pool() can be used as the last
statement to access to the pool just like the regular workers,
put_unbound_pool() will wait for it to detach and then free the pool.

So we move the worker_detach_from_pool() down, make it coincide with
the regular workers.

tj: Minor description update.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

parent 051e1850

kernel/workqueue.c

+6 −8

Original line number	Diff line number	Diff line
		@@ -2253,15 +2253,10 @@ static int rescuer_thread(void *__rescuer)
		move_linked_works(work, scheduled, &n);

		process_scheduled_works(rescuer);
		spin_unlock_irq(&pool->lock);

		worker_detach_from_pool(rescuer, pool);

		spin_lock_irq(&pool->lock);

		/*
		* Put the reference grabbed by send_mayday(). @pool won't
		* go away while we're holding its lock.
		* go away while we're still attached to it.
		*/
		put_pwq(pwq);

		@@ -2274,8 +2269,11 @@ static int rescuer_thread(void *__rescuer)
		wake_up_worker(pool);

		rescuer->pool = NULL;
		spin_unlock(&pool->lock);
		spin_lock(&wq_mayday_lock);
		spin_unlock_irq(&pool->lock);

		worker_detach_from_pool(rescuer, pool);

		spin_lock_irq(&wq_mayday_lock);
		}

		spin_unlock_irq(&wq_mayday_lock);