Before the rescuer is picked to running, the works of the @pwq may be processed by some other workers, and destroy_workqueue() may called at the same time. This may result a nasty situation that rescuer may exit with non-empty mayday list.
It is no harm currently, destroy_workqueue() can safely to free them all(workqueue&pwqs) togerther, since the rescuer is stopped. No rescuer nor mayday-timer can access the mayday list. But it is nasty and error-prone in future develop. Fix it. Signed-off-by: Lai Jiangshan <la...@cn.fujitsu.com> --- kernel/workqueue.c | 12 ++++++------ 1 files changed, 6 insertions(+), 6 deletions(-) diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 0ee63af..832125f 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -2409,12 +2409,6 @@ static int rescuer_thread(void *__rescuer) repeat: set_current_state(TASK_INTERRUPTIBLE); - if (kthread_should_stop()) { - __set_current_state(TASK_RUNNING); - rescuer->task->flags &= ~PF_WQ_WORKER; - return 0; - } - /* see whether any pwq is asking for help */ spin_lock_irq(&wq_mayday_lock); @@ -2459,6 +2453,12 @@ repeat: spin_unlock_irq(&wq_mayday_lock); + if (kthread_should_stop()) { + __set_current_state(TASK_RUNNING); + rescuer->task->flags &= ~PF_WQ_WORKER; + return 0; + } + /* rescuers should never participate in concurrency management */ WARN_ON_ONCE(!(rescuer->flags & WORKER_NOT_RUNNING)); schedule(); -- 1.7.4.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/