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| author | Oleg Nesterov <oleg@tv-sign.ru> | 2008-07-30 09:33:49 +0400 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-07-30 20:41:47 +0400 |
| commit | 6af8bf3d86d55c98af6e453cb920ddc30867e5c7 (patch) | |
| tree | a82494403b76591082a2dc391da3136c6674b356 | |
| parent | dbacefc9c4f6bd365243db379473ab7041656d90 (diff) | |
| download | linux-6af8bf3d86d55c98af6e453cb920ddc30867e5c7.tar.xz | |
workqueues: add comments to __create_workqueue_key()
Dmitry Adamushko pointed out that the error handling in
__create_workqueue_key() is not clear, add the comment.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Dmitry Adamushko <dmitry.adamushko@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | kernel/workqueue.c | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/kernel/workqueue.c b/kernel/workqueue.c index ec7e4f62aaff..4a26a1382df0 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -830,10 +830,21 @@ struct workqueue_struct *__create_workqueue_key(const char *name, start_workqueue_thread(cwq, -1); } else { cpu_maps_update_begin(); + /* + * We must place this wq on list even if the code below fails. + * cpu_down(cpu) can remove cpu from cpu_populated_map before + * destroy_workqueue() takes the lock, in that case we leak + * cwq[cpu]->thread. + */ spin_lock(&workqueue_lock); list_add(&wq->list, &workqueues); spin_unlock(&workqueue_lock); - + /* + * We must initialize cwqs for each possible cpu even if we + * are going to call destroy_workqueue() finally. Otherwise + * cpu_up() can hit the uninitialized cwq once we drop the + * lock. + */ for_each_possible_cpu(cpu) { cwq = init_cpu_workqueue(wq, cpu); if (err || !cpu_online(cpu)) |