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 
 
Home Products Support Community News
 
   
 

xen-devel

Re: [Xen-devel] [PATCH] serialize suspend-resume process

To: BVK Chaitanya <bayapuneni_chaitanya@xxxxxxxxxxxx>
Subject: Re: [Xen-devel] [PATCH] serialize suspend-resume process
From: Keir Fraser <keir.fraser@xxxxxxxxxxxxx>
Date: Thu, 31 Jul 2008 13:23:04 +0100
Cc: Xen-devel@xxxxxxxxxxxxxxxxxxx
Delivery-date: Thu, 31 Jul 2008 05:23:35 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <4891A8A4.7010506@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/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
Thread-index: AcjzCC4sbNji7l77Ed2L3gAX8io7RQ==
Thread-topic: [Xen-devel] [PATCH] serialize suspend-resume process
User-agent: Microsoft-Entourage/11.4.0.080122
On 31/7/08 12:57, "BVK Chaitanya" <bayapuneni_chaitanya@xxxxxxxxxxxx> wrote:

> Yes, but there must be a way for dom0 to know that suspend-resume cycle
> is completed.  Currently dom0 only gets suspend completed notification
> -- as part of shutdown hypercall -- but no resume
> (xenbus_suspend_cancel) completed notification.
> 
> If dom0 issues second suspend request before resume is completed a _new_
> kthread is started and will proceed with xen_suspend in parallel.  I saw
> this hitting BUG_ON in netfront_accelerator_add_watch.

That isn't true. xen_suspend() can only be re-entered after it has switched
the 'shutting_down' variable to SHUTDOWN_INVALID. At this point resume work
is completed (except perhaps for resuming some PV devices via xenbus, which
is done asynchronously).

Your BUG_ON() may be fixed by linux-2.6.18-xen.hg, changeset 622.

 -- Keir



_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel