Commit 4e49627b authored Sep 05, 2009 by Oleg Nesterov Committed by Linus Torvalds Sep 05, 2009

workqueues: introduce __cancel_delayed_work()

cancel_delayed_work() has to use del_timer_sync() to guarantee the timer
function is not running after return.  But most users doesn't actually
need this, and del_timer_sync() has problems: it is not useable from
interrupt, and it depends on every lock which could be taken from irq.

Introduce __cancel_delayed_work() which calls del_timer() instead.

The immediate reason for this patch is
http://bugzilla.kernel.org/show_bug.cgi?id=13757


but hopefully this helper makes sense anyway.

As for 13757 bug, actually we need requeue_delayed_work(), but its
semantics are not yet clear.

Merge this patch early to resolves cross-tree interdependencies between
input and infiniband.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Roland Dreier <rdreier@cisco.com>
Cc: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 37d0892c

include/linux/workqueue.h

+15 −0

Original line number	Diff line number	Diff line
		@@ -240,6 +240,21 @@ static inline int cancel_delayed_work(struct delayed_work *work)
		return ret;
		}

		/*
		* Like above, but uses del_timer() instead of del_timer_sync(). This means,
		* if it returns 0 the timer function may be running and the queueing is in
		* progress.
		*/
		static inline int __cancel_delayed_work(struct delayed_work *work)
		{
		int ret;

		ret = del_timer(&work->timer);
		if (ret)
		work_clear_pending(&work->work);
		return ret;
		}

		extern int cancel_delayed_work_sync(struct delayed_work *work);

		/* Obsolete. use cancel_delayed_work_sync() */