tree 743d6a619538cda98495aaaac67a86246d3007e4
parent b9aac8e0d32499217417ff0b494731811f185b18
author Oleg Nesterov <oleg@tv-sign.ru> 1178703260 -0700
committer Linus Torvalds <torvalds@woody.linux-foundation.org> 1178739053 -0700

worker_thread: fix racy try_to_freeze() usage

worker_thread() can miss freeze_process()->signal_wake_up() if it happens
between try_to_freeze() and prepare_to_wait().  We should check freezing()
before entering schedule().

This race was introduced by me in

	[PATCH 1/1] workqueue: don't migrate pending works from the dead CPU

Looks like mm/vmscan.c:kswapd() has the same race.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>