Messages in this thread |  | | Date | Fri, 17 Nov 2006 16:14:41 +0100 | From | Pavel Machek <> | Subject | Re: [PATCH -mm 0/2] Use freezeable workqueues to avoid suspend-related XFS corruptions |
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On Fri 2006-11-17 11:50:52, David Chinner wrote: > On Thu, Nov 16, 2006 at 09:12:49AM +0100, Rafael J. Wysocki wrote: > > Hi, > > > > The following two patches introduce a mechanism that should allow us to > > avoid suspend-related corruptions of XFS without the freezing of bdevs which > > Pavel considers as too invasive (apart from this, the freezing of bdevs may > > lead to some undesirable interactions with dm and for now it seems to be > > supported for real by XFS only). > > Has this been tested and proven to fix the problem with XFS? It's > been asserted that this will fix XFS and suspend, but it's > not yet been proven that this is even the problem. > > I think the problem is a race between sys_sync, the kernel thread > freeze and the xfsbufd flushing async, delayed write metadata > buffers resulting in a inconsistent suspend image being created. > If this is the case, then freezing the workqueues does not > fix the problem. i.e: > > suspend xfs > ------- --- > sys_sync completes > xfsbufd flushes delwri metadata > kernel thread freeze > workqueue freeze > suspend image start > async I/O starts to complete > suspend image finishes > async I/O all complete
This can't happen, because creating suspend image is atomic. (No interrupts, no DMAs, no drivers running). Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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