From edab2516a6c1752e8e5e3d55727cabf12346e5df Mon Sep 17 00:00:00 2001 From: Andrew Morton Date: Wed, 9 May 2007 02:33:53 -0700 Subject: [PATCH] flush_workqueue(): use preempt_disable to hold off cpu hotplug Cc: Oleg Nesterov Cc: Srivatsa Vaddagiri Cc: Gautham Shenoy Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/workqueue.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 918d55267a12..5176d51bcc2a 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -419,18 +419,22 @@ static void flush_cpu_workqueue(struct cpu_workqueue_struct *cwq) * Probably keventd trying to flush its own queue. So simply run * it by hand rather than deadlocking. */ - mutex_unlock(&workqueue_mutex); + preempt_enable(); + /* + * We can still touch *cwq here because we are keventd, and + * hot-unplug will be waiting us to exit. + */ run_workqueue(cwq); - mutex_lock(&workqueue_mutex); + preempt_disable(); } else { struct wq_barrier barr; init_wq_barrier(&barr); __queue_work(cwq, &barr.work); - mutex_unlock(&workqueue_mutex); + preempt_enable(); /* Can no longer touch *cwq */ wait_for_completion(&barr.done); - mutex_lock(&workqueue_mutex); + preempt_disable(); } } @@ -449,7 +453,7 @@ static void flush_cpu_workqueue(struct cpu_workqueue_struct *cwq) */ void fastcall flush_workqueue(struct workqueue_struct *wq) { - mutex_lock(&workqueue_mutex); + preempt_disable(); /* CPU hotplug */ if (is_single_threaded(wq)) { /* Always use first cpu's area. */ flush_cpu_workqueue(per_cpu_ptr(wq->cpu_wq, singlethread_cpu)); @@ -459,7 +463,7 @@ void fastcall flush_workqueue(struct workqueue_struct *wq) for_each_online_cpu(cpu) flush_cpu_workqueue(per_cpu_ptr(wq->cpu_wq, cpu)); } - mutex_unlock(&workqueue_mutex); + preempt_enable(); } EXPORT_SYMBOL_GPL(flush_workqueue); -- 2.20.1