Messages in this thread Patch in this message | | | Date | Fri, 28 Aug 2009 20:00:15 +0200 | From | Oleg Nesterov <> | Subject | [PATCH 1/1] introduce __cancel_delayed_work() |
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cancel_delayed_work() has to use del_timer_sync() to guarantee the timer function is not running after return. But most users doesn't actually need this, and del_timer_sync() has problems: it is not useable from interrupt, and it depends on every lock which could be taken from irq.
Introduce __cancel_delayed_work() which calls del_timer() instead.
The immediate reason for this patch is http://bugzilla.kernel.org/show_bug.cgi?id=13757 but hopefully this helper makes sense anyway.
As for 13757 bug, actually we need requeue_delayed_work(), but its semantics is not clear yet.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
--- MINI/include/linux/workqueue.h~CDW 2009-08-27 20:17:08.000000000 +0200 +++ MINI/include/linux/workqueue.h 2009-08-27 20:22:48.000000000 +0200 @@ -240,6 +240,21 @@ static inline int cancel_delayed_work(st return ret; } +/* + * Like above, but uses del_timer() instead of del_timer_sync(). This means, + * if it returns 0 the timer function may be running and the queueing is in + * progress. + */ +static inline int __cancel_delayed_work(struct delayed_work *work) +{ + int ret; + + ret = del_timer(&work->timer); + if (ret) + work_clear_pending(&work->work); + return ret; +} + extern int cancel_delayed_work_sync(struct delayed_work *work); /* Obsolete. use cancel_delayed_work_sync() */
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