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] blocking Xen 3.X production use: soft lockup bugs

To: "Ian Pratt" <m+Ian.Pratt@xxxxxxxxxxxx>
Subject: Re: [Xen-devel] blocking Xen 3.X production use: soft lockup bugs
From: Keir Fraser <Keir.Fraser@xxxxxxxxxxxx>
Date: Thu, 3 Aug 2006 09:03:18 +0100
Cc: xen-devel <xen-devel@xxxxxxxxxxxxxxxxxxx>, Steve Traugott <stevegt@xxxxxxxxxxxxx>
Delivery-date: Thu, 03 Aug 2006 01:03:41 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxx
In-reply-to: <A95E2296287EAD4EB592B5DEEFCE0E9D572305@xxxxxxxxxxxxxxxxxxxxxxxxxxx>
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>
References: <A95E2296287EAD4EB592B5DEEFCE0E9D572305@xxxxxxxxxxxxxxxxxxxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx

On 2 Aug 2006, at 23:25, Ian Pratt wrote:

Do we have any consensus that this bug is fixed at all in
xen-3.0-testing, or even unstable?  Is anyone who was hitting soft
lockups in testing *not* hitting them any more on the same hardware?
If so, what changeset are you on now?

Soft lockups could be due to a huge variety of causes. It's unlikely to
be a hardware issue, and since the problems seem to be experienced by a
very small number of users my guess would be that it's configuration
dependent, most likely networking.

Also older versions using sedf scheduler (which has now been patched to avoid this) could end up with domain0 consuming all CPU and starving other guests, leading to softlockup errors. We haven't seen any such errors on our own test machines since this was fixed. Of course, that doesn't mean there aren't problems with other test scenarios!

 -- Keir

Xen-devel mailing list