This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
Home Products Support Community News


Re: [Xen-devel] Where is xtime updated in a domU with an independent wal

To: xen-devel@xxxxxxxxxxxxxxxxxxx
Subject: Re: [Xen-devel] Where is xtime updated in a domU with an independent wallclock?
From: Jay Patel <nitrofin@xxxxxxxxx>
Date: Wed, 2 May 2007 12:22:19 -0700 (PDT)
Delivery-date: Wed, 02 May 2007 12:20:49 -0700
Domainkey-signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=X-YMail-OSG:Received:Date:From:Subject:To:In-Reply-To:MIME-Version:Content-Type:Content-Transfer-Encoding:Message-ID; b=mRow/4pRUnJtSLgr69yGmDMuhyuzlcrloCOmJIsEalXKlDySMLVNx1bkZoLk32lfqYOViHsUBNLja8Hayq7cM4xwF6dSaSZbW+eee+ocguUcg95S9HL8UGllLLmvFoLS9RbqS/WaO2PRSr8KvFVHIm5N+uOgJAEqsC4Xx4NmPrA=;
Envelope-to: www-data@xxxxxxxxxxxxxxxxxx
In-reply-to: <C25DF941.6B41%Keir.Fraser@xxxxxxxxxxxx>
List-help: <mailto:xen-devel-request@lists.xensource.com?subject=help>
List-id: Xen developer discussion <xen-devel.lists.xensource.com>
List-post: <mailto:xen-devel@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx

Keir Fraser <Keir.Fraser@xxxxxxxxxxxx> wrote:

On 2/5/07 07:41, "Jay Patel" <nitrofin@xxxxxxxxx> wrote:

I have just started looking at the code for Xen so please bear with me.
A domU Linux kernel running with independent_wallclock=1 seems to sync its  time with dom0 after every "xm unpause" (obviously preceded by an "xm  pause").
I don't see where the xtime variable is being updated after an "xm unpause",  i.e., domain_unpause_by_systemcontroller(). Right after the unpause, it seems to  me that the xtime in the domU should be what it were just prior to the  pause.

Yes, a guest with independent wallclock should never sync with the wallclock time record provided by Xen, even after an unpause (the unpause is not explicitly visible to the guest anyway).

 -- Keir
Xen-devel mailing list

Ahhh...imagining that irresistible "new car" smell?
Check out new cars at Yahoo! Autos.
Xen-devel mailing list