Messages in this thread | | | From | "Rafael J. Wysocki" <> | Subject | Re: spinlock in completion_done() (was: Re: Async resume patch (was: Re: [GIT PULL] PM updates for 2.6.33)) | Date | Wed, 9 Dec 2009 23:37:52 +0100 |
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On Wednesday 09 December 2009, Ingo Molnar wrote: > > * Rafael J. Wysocki <rjw@sisk.pl> wrote: > > > On Tuesday 08 December 2009, Alan Stern wrote: > > > On Tue, 8 Dec 2009, Rafael J. Wysocki wrote: > > > > > > > BTW, is there a good reason why completion_done() doesn't use spin_lock_irqsave > > > > and spin_unlock_irqrestore? complete() and complete_all() use them, so why not > > > > here? > > > > > > And likewise in try_wait_for_completion(). It looks like a bug. Maybe > > > these routines were not intended to be called with interrupts disabled, > > > but that requirement doesn't seem to be documented. And it isn't a > > > natural requirement anyway. > > > > OK, let's ask Ingo about that. > > > > Ingo, is there any particular reason why completion_done() and > > try_wait_for_completion() don't use spin_lock_irqsave() and > > spin_unlock_irqrestore()? > > that's a bug that should be fixed - all the wakeup side (and atomic) > variants of completetion API should be irq safe. > > It appears that these new completion APIs were added via the XFS tree > about a year ago: > > 39d2f1a: [XFS] extend completions to provide XFS object flush requirements > > Please Cc: scheduler folks to all scheduler patches.
If you haven't fixed it locally yet, would you mind me posting a fix?
Rafael
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