Commit 58629d48 authored by Lai Jiangshan's avatar Lai Jiangshan Committed by Tejun Heo
Browse files

workqueue: Always queue work items to the newest PWQ for order workqueues 



To ensure non-reentrancy, __queue_work() attempts to enqueue a work
item to the pool of the currently executing worker. This is not only
unnecessary for an ordered workqueue, where order inherently suggests
non-reentrancy, but it could also disrupt the sequence if the item is
not enqueued on the newest PWQ.

Just queue it to the newest PWQ and let order management guarantees
non-reentrancy.

Signed-off-by: default avatarLai Jiangshan <jiangshan.ljs@antgroup.com>
Fixes: 4c065dbc ("workqueue: Enable unbound cpumask update on ordered workqueues")
Cc: stable@vger.kernel.org # v6.9+
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
(cherry picked from commit 74347be3edfd11277799242766edf844c43dd5d3)
parent b2b1f933

kernel/workqueue.c

+5 −1
Original line number Diff line number Diff line
@@ -2274,9 +2274,13 @@ static void __queue_work(int cpu, struct workqueue_struct *wq, 
	 * If @work was previously on a different pool, it might still be

	 * running there, in which case the work needs to be queued on that

	 * pool to guarantee non-reentrancy.

	 *

	 * For ordered workqueue, work items must be queued on the newest pwq

	 * for accurate order management.  Guaranteed order also guarantees

	 * non-reentrancy.  See the comments above unplug_oldest_pwq().

	 */

	last_pool = get_work_pool(work);

	if (last_pool && last_pool != pool) {

	if (last_pool && last_pool != pool && !(wq->flags & __WQ_ORDERED)) {

		struct worker *worker;



		raw_spin_lock(&last_pool->lock);