Messages in this thread | | | Date | Sat, 5 May 2007 11:42:54 +0000 | From | Pavel Machek <> | Subject | Re: Back to the future. |
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Hi!
> > The "let's stop all kernel threads" is superstition. It's the same kind of > > superstition that made people write "sync" three times before turning off > > the power in the olden times. It's the kind of superstition that comes > > from "we don't do things right, so let's be vewy vewy quiet and _pray_ > > that it works when we are beign quiet". > > Side note: while I think things should probably *work* even with user > processes going full bore while a snapshot it taken, I'll freely admit > that I'll follow that superstition far enough that I think it's probably a > good idea to try to quiesce the system to _some_ degree, and that stopping > user programs is a good idea. Partly because the whole memory shrinking > thing, and partly just because we should do the snapshot with hw IO queues > empty. > > But I don't think it would necessarily be wrong (and in many ways it would > probably be *right*) to do that IO queue stopping at the queue level > rather than at a process level. Why stop processes just becasue you want > to clean out IO queues? They are two totally different things!
Actually, I'd like to stop I/O queues; if there was easy way to do that, I'll happily switch. Notice that we'll need to stop 'I/O queues' of the char devices, too... 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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