From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757685Ab3ENRw6 (ORCPT ); Tue, 14 May 2013 13:52:58 -0400 Received: from mail-pd0-f178.google.com ([209.85.192.178]:37506 "EHLO mail-pd0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754057Ab3ENRw5 (ORCPT ); Tue, 14 May 2013 13:52:57 -0400 Message-ID: <519279F6.8010401@linaro.org> Date: Tue, 14 May 2013 10:52:54 -0700 From: John Stultz User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130404 Thunderbird/17.0.5 MIME-Version: 1.0 To: David Vrabel CC: xen-devel@lists.xen.org, Konrad Rzeszutek Wilk , Thomas Gleixner , linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/3] x86: increase precision of x86_platform.get/set_wallclock() References: <1368467768-2316-1-git-send-email-david.vrabel@citrix.com> <1368467768-2316-2-git-send-email-david.vrabel@citrix.com> In-Reply-To: <1368467768-2316-2-git-send-email-david.vrabel@citrix.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 05/13/2013 10:56 AM, David Vrabel wrote: > From: David Vrabel > > All the virtualized platforms (KVM, lguest and Xen) have persistent > wallclocks that have more than one second of precision. > > read_persistent_wallclock() and update_persistent_wallclock() allow > for nanosecond precision but their implementation on x86 with > x86_platform.get/set_wallclock() only allows for one second precision. > This means guests may see a wallclock time that is off by up to 1 > second. > > Make set_wallclock() and get_wallclock() take a struct timespec > parameter (which allows for nanosecond precision) so KVM and Xen > guests may start with a more accurate wallclock time and a Xen dom0 > can maintain a more accurate wallclock for guests. > > Signed-off-by: David Vrabel I've gone ahead and queued this one for 3.11 thanks -john