Files
kernel_arpi/include/linux
Oleg Nesterov db70089722 workqueues: implement flush_work()
Most of users of flush_workqueue() can be changed to use cancel_work_sync(),
but sometimes we really need to wait for the completion and cancelling is not
an option. schedule_on_each_cpu() is good example.

Add the new helper, flush_work(work), which waits for the completion of the
specific work_struct. More precisely, it "flushes" the result of of the last
queue_work() which is visible to the caller.

For example, this code

	queue_work(wq, work);
	/* WINDOW */
	queue_work(wq, work);

	flush_work(work);

doesn't necessary work "as expected". What can happen in the WINDOW above is

	- wq starts the execution of work->func()

	- the caller migrates to another CPU

now, after the 2nd queue_work() this work is active on the previous CPU, and
at the same time it is queued on another. In this case flush_work(work) may
return before the first work->func() completes.

It is trivial to add another helper

	int flush_work_sync(struct work_struct *work)
	{
		return flush_work(work) || wait_on_work(work);
	}

which works "more correctly", but it has to iterate over all CPUs and thus
it much slower than flush_work().

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Acked-by: Max Krasnyansky <maxk@qualcomm.com>
Acked-by: Jarek Poplawski <jarkao2@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-25 10:53:40 -07:00
..
2008-07-25 10:53:30 -07:00
2008-07-21 21:55:03 -07:00
2008-07-14 14:52:56 -04:00
2008-07-01 11:28:06 +10:00
2008-06-19 10:42:17 +10:00
2008-06-19 10:42:17 +10:00
2008-07-24 10:47:24 -07:00
2008-07-24 10:47:33 -07:00
2008-07-24 10:47:33 -07:00
2008-07-03 13:21:14 +02:00
2008-06-06 11:29:10 -07:00
2008-05-29 01:38:46 -07:00
2008-07-04 10:40:05 -07:00
2008-07-25 10:53:33 -07:00
2008-07-20 17:12:38 -07:00
2008-07-22 17:30:57 -07:00
2008-07-11 10:46:50 +02:00
2008-07-21 12:00:37 +01:00
2008-07-21 12:00:37 +01:00
2008-07-24 10:47:29 -07:00
2008-05-07 09:48:23 +02:00
2008-07-24 10:47:41 -07:00
2008-05-16 17:22:26 -04:00
2008-05-01 13:08:16 -04:00
2008-07-08 17:55:41 +02:00
2008-07-16 23:27:03 +02:00
2008-07-24 10:47:29 -07:00
2008-07-11 15:49:21 +02:00
2008-05-13 08:02:26 -07:00
2008-07-20 17:12:36 -07:00
2008-07-25 10:53:30 -07:00
2008-07-20 17:12:36 -07:00
2008-07-23 15:25:21 +02:00
2008-05-20 16:44:43 +02:00
2008-06-11 21:00:38 -07:00
2008-07-18 18:05:19 -07:00
2008-06-11 21:00:38 -07:00
2008-07-14 22:49:06 -07:00
2008-07-03 17:51:57 +09:00
2008-07-25 10:53:39 -07:00
2008-07-25 10:53:28 -07:00
2008-05-05 16:47:14 +10:00
2008-07-16 23:27:07 +02:00
2008-06-11 21:00:38 -07:00
2008-07-20 17:12:37 -07:00
2008-05-20 12:17:39 -04:00
2008-07-25 10:53:29 -07:00
2008-07-25 10:53:34 -07:00
2008-07-25 10:53:29 -07:00
2008-07-24 10:47:17 -07:00
2008-07-04 10:40:05 -07:00
2008-07-20 12:42:32 +03:00
2008-07-23 09:49:56 +01:00
2008-07-24 10:47:41 -07:00
2008-05-23 22:26:03 +02:00
2008-07-25 10:53:40 -07:00
2008-07-24 10:47:24 -07:00
2008-07-25 10:53:34 -07:00
2008-06-06 11:29:12 -07:00
2008-07-25 10:53:29 -07:00
2008-07-24 10:47:15 -07:00
2008-07-24 11:50:15 -07:00
2008-06-10 14:37:03 -07:00
2008-07-07 16:26:50 -07:00
2008-05-06 12:01:41 -04:00
2008-06-11 21:00:38 -07:00
2008-06-11 21:00:38 -07:00
2008-07-22 14:19:19 -07:00
2008-05-19 16:25:39 +01:00
2008-07-25 10:53:29 -07:00
2008-05-19 10:01:36 +02:00
2008-07-04 10:40:07 -07:00
2008-07-25 10:53:29 -07:00
2008-05-25 07:09:47 +02:00
2008-07-24 10:47:33 -07:00
2008-07-24 10:47:22 -07:00
2008-07-24 08:31:21 -04:00
2008-07-24 10:47:24 -07:00
2008-07-14 22:49:06 -07:00
2008-07-24 10:47:21 -07:00
2008-07-04 10:40:04 -07:00
2008-07-25 10:53:30 -07:00
2008-06-20 14:05:53 -06:00
2008-07-04 11:26:40 +02:00
2008-07-20 17:12:37 -07:00
2008-06-12 14:25:09 -07:00
2008-06-12 10:48:00 +02:00
2008-07-22 13:03:28 -07:00
2008-07-20 17:12:34 -07:00
2008-07-22 13:03:27 -07:00
2008-07-21 15:15:55 -07:00
2008-05-09 07:45:18 -07:00
2008-07-24 10:47:14 -07:00
2008-07-25 10:53:40 -07:00