Messages in this thread Patch in this message | | | Date | Tue, 29 Jul 2008 20:22:46 +0400 | From | Oleg Nesterov <> | Subject | [PATCH] workqueues: add comments to __create_workqueue_key() |
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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>
--- LINUS/kernel/workqueue.c~ 2008-07-29 17:59:48.000000000 +0400 +++ LINUS/kernel/workqueue.c 2008-07-29 18:41:06.000000000 +0400 @@ -830,10 +830,21 @@ struct workqueue_struct *__create_workqu 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))
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