From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Winchell Subject: Re: Re: Fix for get_s_time() Date: Thu, 24 Apr 2008 14:32:39 -0400 Message-ID: <4810D247.7040400@virtualiron.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Keir Fraser Cc: Dave Winchell , "Tian, Kevin" , "xen-devel@lists.xensource.com" , Ian Pratt , "dan.magenheimer@oracle.com" List-Id: xen-devel@lists.xenproject.org Keir Fraser wrote: >On 24/4/08 17:04, "Dave Winchell" wrote: > > > >>yes, this is the issue. What you suggest should be fine and I am trying >>it now. >>With the locking version (and a fix to a bug I introduced) I got .0012% >>error >>on an overnight run with hpet layered on get_s_time_mono(), which is the >>max(prev, cur) layer on get_s_time we discussed. >> >> > >12 parts per million is pretty good. Is that cumulative deviation from 'wall >time' over ~12 hours? > yes, deviation between the guest's time and an ntp reference. > That could easily be explained by the fact that Xen >system time is not sync'ed with ntp. > > That's true. And, as we have discussed, this error seems to vary quite a bit platform to platform for some reason. I will verify that this still is the case. -Dave > -- Keir > > > >