Messages in this thread | | | From | David Howells <> | Subject | Re: [RFC,PATCH] workqueues: turn queue_work() into the "barrier" for work->func() | Date | Tue, 11 Nov 2008 22:46:21 +0000 |
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Oleg Nesterov <oleg@redhat.com> wrote:
> I think the caller of queue_work() has all rights to expect that > the next invocation of work_func() must see "VAR == 1", but this > is not true if the work is already pending.
As you said, queue_work() does test_and_set_bit() which implies smp_mb() either side of the function, so you're half way there, and run_workqueue() calls spin_unlock_irq() just before calling work_clear_pending()... So might it make sense to move the work_clear_pending() into locked section? Or would that require an smp_mb__before_clear_bit()?
David
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