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| author | Oleg Nesterov <oleg@tv-sign.ru> | 2007-05-09 02:34:20 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-05-09 12:30:53 -0700 |
| commit | 85f4186af944c1240c84934a9ab578743df2d69b (patch) | |
| tree | 743d6a619538cda98495aaaac67a86246d3007e4 | |
| parent | b9aac8e0d32499217417ff0b494731811f185b18 (diff) | |
| download | linux-85f4186af944c1240c84934a9ab578743df2d69b.tar.gz linux-85f4186af944c1240c84934a9ab578743df2d69b.tar.bz2 linux-85f4186af944c1240c84934a9ab578743df2d69b.zip | |
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) do_sigaction(SIGCHLD, &sa, (struct k_sigaction *)0); for (;;) { - if (cwq->wq->freezeable) - try_to_freeze(); - prepare_to_wait(&cwq->more_work, &wait, TASK_INTERRUPTIBLE); - if (!cwq->should_stop && list_empty(&cwq->worklist)) + if (!freezing(current) && !cwq->should_stop + && list_empty(&cwq->worklist)) schedule(); finish_wait(&cwq->more_work, &wait); + try_to_freeze(); + if (cwq_should_stop(cwq)) break; |