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] [PATCH] Fix xm save timeout with paused domains

To: John Levon <levon@xxxxxxxxxxxxxxxxx>
Subject: Re: [Xen-devel] [PATCH] Fix xm save timeout with paused domains
From: Keir Fraser <keir@xxxxxxxxxxxxx>
Date: Tue, 08 May 2007 18:34:03 +0100
Cc: xen-devel@xxxxxxxxxxxxxxxxxxx
Delivery-date: Tue, 08 May 2007 10:30:45 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxx
In-reply-to: <20070508171435.GC19237@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: AceRlxHqUFXxEf2KEdu3jwAWy6hiGQ==
Thread-topic: [Xen-devel] [PATCH] Fix xm save timeout with paused domains
User-agent: Microsoft-Entourage/
On 8/5/07 18:14, "John Levon" <levon@xxxxxxxxxxxxxxxxx> wrote:

>> I think xend is the obvious place to implement this type of synchronisation.
> I think I agree. It would be easy if we were to just loop until the
> domain gets unpaused but that's not really quite the correct fix, since
> we ideally want 'xm save' to fail cleanly if the domain is paused (I
> vaguely remember seeing a patch for this go past?).
>> The only question is how hard it will be to add in.
> Maybe a xenstore entry for the domain which is written just after the
> .unpause() (the absence of this would also prevent xm pause, xm destroy,
> perhaps)

Yes, some kind of state field in xenstore to aid synchronisation wouldn't be
a bad idea. It could be set to various states depending on whether a domain
is starting, xm-paused, being saved, etc. and operation can sync on that
field by waiting for it to switch to 'running'.

 -- Keir

Xen-devel mailing list