diff options
author | Oleg Nesterov <oleg@tv-sign.ru> | 2007-05-09 05:34:20 -0400 |
---|---|---|
committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-05-09 15:30:53 -0400 |
commit | 85f4186af944c1240c84934a9ab578743df2d69b (patch) | |
tree | 743d6a619538cda98495aaaac67a86246d3007e4 | |
parent | b9aac8e0d32499217417ff0b494731811f185b18 (diff) |
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>
-rw-r--r-- | kernel/workqueue.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 87693b37d017..63885abf1ba0 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c | |||
@@ -308,14 +308,14 @@ static int worker_thread(void *__cwq) | |||
308 | do_sigaction(SIGCHLD, &sa, (struct k_sigaction *)0); | 308 | do_sigaction(SIGCHLD, &sa, (struct k_sigaction *)0); |
309 | 309 | ||
310 | for (;;) { | 310 | for (;;) { |
311 | if (cwq->wq->freezeable) | ||
312 | try_to_freeze(); | ||
313 | |||
314 | prepare_to_wait(&cwq->more_work, &wait, TASK_INTERRUPTIBLE); | 311 | prepare_to_wait(&cwq->more_work, &wait, TASK_INTERRUPTIBLE); |
315 | if (!cwq->should_stop && list_empty(&cwq->worklist)) | 312 | if (!freezing(current) && !cwq->should_stop |
313 | && list_empty(&cwq->worklist)) | ||
316 | schedule(); | 314 | schedule(); |
317 | finish_wait(&cwq->more_work, &wait); | 315 | finish_wait(&cwq->more_work, &wait); |
318 | 316 | ||
317 | try_to_freeze(); | ||
318 | |||
319 | if (cwq_should_stop(cwq)) | 319 | if (cwq_should_stop(cwq)) |
320 | break; | 320 | break; |
321 | 321 | ||