From: Philipp Stanner Date: Fri, 4 Apr 2025 10:15:44 +0000 (+0200) Subject: workqueue: Better document teardown for delayed_work X-Git-Tag: v6.16-rc1~155^2~2 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=24cdab5787a0ae90260df1f8ac8284877a70b7b3;p=thirdparty%2Flinux.git workqueue: Better document teardown for delayed_work destroy_workqueue() does not ensure that non-pending work submitted with queue_delayed_work() gets cancelled. The caller has to ensure that manually. Add this information about delayed_work in destroy_workqueue()'s docstring. Add a TODO for destroy_workqueue() to wait for all delayed_work. Signed-off-by: Philipp Stanner Signed-off-by: Tejun Heo --- diff --git a/kernel/workqueue.c b/kernel/workqueue.c index cf62032827375..2cb8276a27a99 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -5837,6 +5837,17 @@ static bool pwq_busy(struct pool_workqueue *pwq) * @wq: target workqueue * * Safely destroy a workqueue. All work currently pending will be done first. + * + * This function does NOT guarantee that non-pending work that has been + * submitted with queue_delayed_work() and similar functions will be done + * before destroying the workqueue. The fundamental problem is that, currently, + * the workqueue has no way of accessing non-pending delayed_work. delayed_work + * is only linked on the timer-side. All delayed_work must, therefore, be + * canceled before calling this function. + * + * TODO: It would be better if the problem described above wouldn't exist and + * destroy_workqueue() would cleanly cancel all pending and non-pending + * delayed_work. */ void destroy_workqueue(struct workqueue_struct *wq) {