From: David Vrabel <david.vrabel@citrix.com>
To: <xen-devel@lists.xen.org>
Cc: David Vrabel <david.vrabel@citrix.com>,
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
John Stultz <john.stultz@linaro.org>,
<linux-kernel@vger.kernel.org>
Subject: [PATCHv2 0/2] xen: maintain an accurate persistent clock in more cases
Date: Tue, 28 May 2013 19:22:46 +0100 [thread overview]
Message-ID: <1369765368-10823-1-git-send-email-david.vrabel@citrix.com> (raw)
The kernel has limited support for updating the persistent clock or
RTC when NTP is synced. This has the following limitations:
* The persistent clock is not updated on step changes. This leaves a
window where it will be incorrect (while NTP resyncs).
* Xen guests use the Xen wallclock as their persistent clock. dom0
maintains this clock so it is persistent for domUs and not dom0
itself.
These series fixes the above limitations and depends on "x86: increase
precision of x86_platform.get/set_wallclock()" which was previously
posted.
Changes since v1:
Reworked to use the pvclock_gtod notifier to sync the wallclock (this
looked similar to what a KVM host does). update_persistent_clock()
will now only update the CMOS RTC.
David
[1] http://lists.xen.org/archives/html/xen-devel/2013-05/msg01402.html
next reply other threads:[~2013-05-28 18:22 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-05-28 18:22 David Vrabel [this message]
2013-05-28 18:22 ` [PATCH 1/2] x86/xen: sync the CMOS RTC as well as the Xen wallclock David Vrabel
2013-05-28 19:01 ` John Stultz
2013-05-28 19:05 ` Konrad Rzeszutek Wilk
2013-05-28 18:22 ` [PATCH 2/2] x86/xen: sync the wallclock when the system time changes David Vrabel
2013-05-28 18:53 ` John Stultz
2013-05-29 7:42 ` [Xen-devel] " Jan Beulich
2013-05-29 9:42 ` David Vrabel
2013-06-04 1:22 ` Marcelo Tosatti
2013-05-29 7:39 ` [Xen-devel] " Jan Beulich
2013-05-29 9:48 ` David Vrabel
2013-05-29 7:47 ` Jan Beulich
2013-05-29 9:37 ` David Vrabel
2013-05-29 19:58 ` John Stultz
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