WARNING - OLD ARCHIVES

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/
Xen

xen-devel

[Top] [All Lists]

Re: [Xen-devel] System time monotonicity

To: John Levon <levon@xxxxxxxxxxxxxxxxx>
Subject: Re: [Xen-devel] System time monotonicity
From: Keir Fraser <keir@xxxxxxxxxxxxx>
Date: 2007年3月27日 11:47:40 +0100
Cc: xen-devel@xxxxxxxxxxxxxxxxxxx
Delivery-date: 2007年3月27日 03:46:51 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxx
In-reply-to: <20070326200447.GA3730@xxxxxxxxxxxxxxxxxxxxxxx>
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
Thread-index: AcdwXVcqlZIA8txQEdu1BgAX8io7RQ==
Thread-topic: [Xen-devel] System time monotonicity
User-agent: Microsoft-Entourage/11.2.5.060620
On 26/3/07 21:04, "John Levon" <levon@xxxxxxxxxxxxxxxxx> wrote:
>> Small backwards time deltas are possible from the current time code. You'll
>> have to filter them out yourself if you can't deal with them. We could add
>> extra code in Xen to stop this happening for any individual VCPU
>
> Some instrumentation indicated that we had cross-VCPU jitter of
> significant deltas, ~18us at worst. Though the instrumentation wasn't
> completely reliable so that might not be accurate.
I should add that time synchronisation is currently broken in xen-unstable,
and has been for about two weeks. I just checked in a patch (based on one
from Jan Beulich) to fix this (changeset 14573:ba9d3fd4ee4b).
 -- Keir
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel
<Prev in Thread] Current Thread [Next in Thread>
Previous by Date: Re: [Xen-devel] RFC: [0/2] Remove netloop by lazy copying in netback , Keir Fraser
Next by Date: Re: [Xen-devel] RFC: [0/2] Remove netloop by lazy copying in netback , Herbert Xu
Previous by Thread: Re: [Xen-devel] System time monotonicity , John Levon
Next by Thread: RE: [Xen-devel] System time monotonicity , Ian Pratt
Indexes: [Date] [Thread] [Top] [All Lists]

Copyright ©, Citrix Systems Inc. All rights reserved. Legal and Privacy
Citrix This site is hosted by Citrix

AltStyle によって変換されたページ (->オリジナル) /