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author | Alan Stern <stern@rowland.harvard.edu> | 2010-02-12 17:39:21 +0900 |
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committer | Tejun Heo <tj@kernel.org> | 2010-04-30 08:57:25 +0200 |
commit | eef6a7d5c2f38adadab8240fabf43730fe796482 (patch) | |
tree | 4ee96327e3f7880bea51bd4e05b37193915c00ae /kernel/workqueue.c | |
parent | 47dd5be2d6a82b8153e059a1d09eb3879d485bfd (diff) | |
download | kernel_samsung_smdk4412-eef6a7d5c2f38adadab8240fabf43730fe796482.zip kernel_samsung_smdk4412-eef6a7d5c2f38adadab8240fabf43730fe796482.tar.gz kernel_samsung_smdk4412-eef6a7d5c2f38adadab8240fabf43730fe796482.tar.bz2 |
workqueue: warn about flush_scheduled_work()
This patch (as1319) adds kerneldoc and a pointed warning to
flush_scheduled_work().
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'kernel/workqueue.c')
-rw-r--r-- | kernel/workqueue.c | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 5bfb213..0225fea 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -845,6 +845,30 @@ int schedule_on_each_cpu(work_func_t func) return 0; } +/** + * flush_scheduled_work - ensure that any scheduled work has run to completion. + * + * Forces execution of the kernel-global workqueue and blocks until its + * completion. + * + * Think twice before calling this function! 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. + */ void flush_scheduled_work(void) { flush_workqueue(keventd_wq); |