Messages in this thread | | | Date | Tue, 1 Aug 2006 00:53:08 +0200 | From | Pavel Machek <> | Subject | Re: XFS vs. swsusp |
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Hi!
> > Rafael has patches to add bdev freezing to swsusp. I'd like to know if > > they are neccessary (and why). > > > > 1) Is sync() enough to guarantee that all the data written before sync > > actually reach the platters? > > > > (Or is it that data only reach the journal? OTOH that would be okay, too). > > It ensures file data reaches its final resting place, and that > metadata changes have been logged. It does not necessarily ....
Okay, good, being safely in the journal is okay.
> > 2) If we stop all the user proceses and all the kernel threads, is > > that enough to prevent XFS from writing to disk? > > Yes, I believe so (if all user processes and kernel threads are > stopped, who else would be left to initiate I/O?). There is a
Well, we were afraid that you'd do it from timer interrupt or something like that.
> timer driven wakeup done on the per-fs xfssyncd kernel threads, > which do background metadata writeout and will write to the log > periodically... but if those processes are all stopped too, you > should be OK.
Timer only wakes up xfssyncd thread, right? That's okay, as that thread will be stopped.
Rafael, I do not think we need bdev freezing changes for XFS. 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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