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author | Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> | 2023-06-30 21:28:53 +0900 |
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committer | Tejun Heo <tj@kernel.org> | 2023-07-10 10:39:17 -1000 |
commit | 20bdedafd2f63e0ba70991127f9b5c0826ebdb32 (patch) | |
tree | fc7307d993e44f29546fb693a43721c5664371ec /include/linux/workqueue.h | |
parent | 3f01e9fed8454dcd89727016c3e5b2fbb8f8e50c (diff) | |
download | linux-20bdedafd2f63e0ba70991127f9b5c0826ebdb32.tar.gz linux-20bdedafd2f63e0ba70991127f9b5c0826ebdb32.tar.bz2 linux-20bdedafd2f63e0ba70991127f9b5c0826ebdb32.zip |
workqueue: Warn attempt to flush system-wide workqueues.
Based on commit c4f135d643823a86 ("workqueue: Wrap flush_workqueue() using
a macro"), all in-tree users stopped flushing system-wide workqueues.
Therefore, start emitting runtime message so that all out-of-tree users
will understand that they need to update their code.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'include/linux/workqueue.h')
-rw-r--r-- | include/linux/workqueue.h | 44 |
1 files changed, 3 insertions, 41 deletions
diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h index 683efe29fa69..1a4223cbdb5f 100644 --- a/include/linux/workqueue.h +++ b/include/linux/workqueue.h @@ -569,6 +569,7 @@ static inline bool schedule_work(struct work_struct *work) /* * Detect attempt to flush system-wide workqueues at compile time when possible. + * Warn attempt to flush system-wide workqueues at runtime. * * See https://lkml.kernel.org/r/49925af7-78a8-a3dd-bce6-cfc02e1a9236@I-love.SAKURA.ne.jp * for reasons and steps for converting system-wide workqueues into local workqueues. @@ -576,52 +577,13 @@ static inline bool schedule_work(struct work_struct *work) extern void __warn_flushing_systemwide_wq(void) __compiletime_warning("Please avoid flushing system-wide workqueues."); -/** - * flush_scheduled_work - ensure that any scheduled work has run to completion. - * - * Forces execution of the kernel-global workqueue and blocks until its - * completion. - * - * It's very easy to get into trouble if you don't take great care. - * Either of the following situations will lead to deadlock: - * - * One of the work items currently on the workqueue needs to acquire - * a lock held by your code or its caller. - * - * Your code is running in the context of a work routine. - * - * They will be detected by lockdep when they occur, but the first might not - * occur very often. It depends on what work items are on the workqueue and - * what locks they need, which you have no control over. - * - * In most situations flushing the entire workqueue is overkill; you merely - * need to know that a particular work item isn't queued and isn't running. - * In such cases you should use cancel_delayed_work_sync() or - * cancel_work_sync() instead. - * - * Please stop calling this function! A conversion to stop flushing system-wide - * workqueues is in progress. This function will be removed after all in-tree - * users stopped calling this function. - */ -/* - * The background of commit 771c035372a036f8 ("deprecate the - * '__deprecated' attribute warnings entirely and for good") is that, - * since Linus builds all modules between every single pull he does, - * the standard kernel build needs to be _clean_ in order to be able to - * notice when new problems happen. Therefore, don't emit warning while - * there are in-tree users. - */ +/* Please stop using this function, for this function will be removed in near future. */ #define flush_scheduled_work() \ ({ \ - if (0) \ - __warn_flushing_systemwide_wq(); \ + __warn_flushing_systemwide_wq(); \ __flush_workqueue(system_wq); \ }) -/* - * Although there is no longer in-tree caller, for now just emit warning - * in order to give out-of-tree callers time to update. - */ #define flush_workqueue(wq) \ ({ \ struct workqueue_struct *_wq = (wq); \ |