Messages in this thread | | | Date | Fri, 28 Jun 2013 18:09:15 +0200 (CEST) | From | Thomas Gleixner <> | Subject | Re: [PATCH 5/5] x86/xen: sync the CMOS RTC as well as the Xen wallclock |
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On Fri, 28 Jun 2013, David Vrabel wrote: > > Before: > > Xen wallclock set when time is stepped. > Xen wallclock set every 11 minutes (by sync_cmos_clock()). > Hardware RTC never set. > > After: > > Xen wallclock set when time is stepped. > Xen wallclock set every 11 minutes (in pvclock gtod notifier).
Ah, you are emulating the sync_cmos_clock() behaviour for the xen wallclock via the periodic pvclock_gtod notifier call.
> Hardware RTC set every 11 minutes (by sync_cmos_clock()). > > I'll update the changelog to be more descriptive: > > Adjustments to Xen's persistent clock via update_persistent_clock() > don't actually persist, as the Xen wallclock is a software only clock > and modifications to it do not modify the underlying CMOS RTC. > > The x86_platform.set_wallclock hook can be used to keep the hardware > RTC synchronized (as on bare metal). If (in dom0) we make the Xen > wallclock periodically synchronized by the pvclock_gtod notifier, the > set_wallclock hook need not update the Xen wallclock and the native > implementation can be used.
Yep. I'll pick that up.
Thanks,
tglx
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