Re: [Xen-devel] Re: [PATCH] x86/pvclock-xen: zero last_value on resume

[Jeremy Fitzhardinge <jeremy@xxxxxxxx>]

 On 10/26/2010 10:48 AM, Glauber Costa wrote:
> 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.

Thanks.

HPA, do you want to take this, or shall I send it on?

Thanks,
    J

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel