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] soft lockups during live migrate..

To: Mukesh Rathor <mukesh.rathor@xxxxxxxxxx>
Subject: Re: [Xen-devel] soft lockups during live migrate..
From: Tim Deegan <Tim.Deegan@xxxxxxxxxx>
Date: Fri, 23 Oct 2009 11:09:36 +0100
Cc: "Xen-Devel \(E-mail\)" <xen-devel@xxxxxxxxxxxxxxxxxxx>
Delivery-date: Fri, 23 Oct 2009 03:09:59 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <20091022212149.32d73745@xxxxxxxxxxxxxxxxxxxx>
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>
References: <20091022212149.32d73745@xxxxxxxxxxxxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
User-agent: Mutt/1.5.18 (2008-05-17)
At 05:21 +0100 on 23 Oct (1256275309), Mukesh Rathor wrote:
> Trying to migrate a 64bit PV guest with 64GB running medium to heavy load 
> on xen 3.4.0, it is showing lot of soft lockups. The softlockups are 
> causing dom0 reboot by the cluster FS. The hardware has 256GB and 32
> CPUs.
> 
> Looking into the hypervisor thru kdb, I see one cpu in sh_resync_all()
> while all other 31 appear spinning on the shadow_lock.

How many vcpus does the guest have?  Scalability issues in the OOS
shadow code are more related to number of VCPUs than amount of RAM.

> I vaguely remember
> seeing some thread on this while ago, but just can't seem to google find
> it now. I'm trying to figure what could be done in the short run.

The solution (for BS2000) was to plumb in a flag that disabled the OOS
code for particular domains. 
 
Tim.

-- 
Tim Deegan <Tim.Deegan@xxxxxxxxxx>
Principal Software Engineer, Citrix Systems (R&D) Ltd.
[Company #02300071, SL9 0DZ, UK.]

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