Messages in this thread | | | Subject | Re: [PATCH] x86/pvclock-xen: zero last_value on resume | From | Glauber Costa <> | Date | Tue, 26 Oct 2010 15:48:54 -0200 |
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On Tue, 2010-10-26 at 09:59 -0700, Jeremy Fitzhardinge wrote: > > If the guest domain has been suspend/resumed or migrated, then the > system clock backing the pvclock clocksource may revert to a smaller > value (ie, can be non-monotonic across the migration/save-restore). > Make sure we zero last_value in that case so that the domain > continues to see clock updates. > > [ I don't know if kvm needs an analogous fix or not. ] After migration, save/restore, etc, we issue an ioctl where we tell the host the last clock value. That (in theory) guarantees monotonicity.
I am not opposed to this patch in any way, however.
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