flush_workqueue(): use preempt_disable to hold off cpu hotplug

Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com>
Cc: Gautham Shenoy <ego@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Andrew Morton 2007-05-09 02:33:53 -07:00 committed by Linus Torvalds
parent b89deed32c
commit edab2516a6

View File

@ -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);