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] Re: [PATCH] blkfront: Move blkif_interrupt into a taskle

To: Jeremy Fitzhardinge <jeremy@xxxxxxxx>
Subject: Re: [Xen-devel] Re: [PATCH] blkfront: Move blkif_interrupt into a tasklet.
From: Andrew Jones <drjones@xxxxxxxxxx>
Date: Fri, 24 Sep 2010 09:14:34 +0200
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>, Xen <xen-devel@xxxxxxxxxxxxxxxxxxx>, Tom Kopec <tek@xxxxxxx>, Daniel Stodden <daniel.stodden@xxxxxxxxxx>
Delivery-date: Fri, 24 Sep 2010 00:15:27 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <4C9B9E1D.2040501@xxxxxxxx>
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: <1282546470-5547-1-git-send-email-daniel.stodden@xxxxxxxxxx> <1282546470-5547-2-git-send-email-daniel.stodden@xxxxxxxxxx> <4C802934.2000305@xxxxxxxx> <4C9B7B69.7080705@xxxxxxxxxx> <4C9B7F1A.2040302@xxxxxxxx> <4C9B826B.10302@xxxxxxxxxx> <4C9B9E1D.2040501@xxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
User-agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv: Gecko/20100907 Fedora/3.0.7-1.fc12 Lightning/1.0b2pre Thunderbird/3.0.7
On 09/23/2010 08:36 PM, Jeremy Fitzhardinge wrote:
>  On 09/23/2010 09:38 AM, Paolo Bonzini wrote:
>> On 09/23/2010 06:23 PM, Jeremy Fitzhardinge wrote:
>>>> Any developments with this? I've got a report of the exact same
>>>> warnings
>>>> on RHEL6 guest. See
>>>> https://bugzilla.redhat.com/show_bug.cgi?id=632802
>>>> RHEL6 doesn't have the 'Move blkif_interrupt into a tasklet' patch, so
>>>> that can be ruled out. Unfortunately I don't have this reproducing on a
>>>> test machine, so it's difficult to debug.  The report I have showed
>>>> that
>>>> in at least one case it occurred on boot up, right after initting the
>>>> block device. I'm trying to get confirmation if that's always the case.
>>>> Thanks in advance for any pointers you might have.
>>> Yes, I see it even after reverting that change as well.  However I only
>>> see it on my domain with an XFS filesystem, but I haven't dug any deeper
>>> to see if that's relevant.
>>> Do you know when this appeared?  Is it recent?  What changes are in the
>>> rhel6 kernel in question?
>> It's got pretty much everything in stable-2.6.32.x, up to the 16 patch
>> blkfront series you posted last July.  There are some RHEL-specific
>> workarounds for PV-on-HVM, but for PV domains everything matches
>> upstream.
> Have you tried bisecting to see when this particular problem appeared? 
> It looks to me like something is accidentally re-enabling interrupts -
> perhaps a stack overrun is corrupting the "flags" argument between a
> spin_lock_irqsave()/restore pair. 

Unfortunately I don't have a test machine where I can do a bisection
(yet). I'm looking for one. I only have this one report so far, and it's
on a production machine.

> Is it only on 32-bit kernels?

This one report I have is a 32b guest on a 64b host.


Xen-devel mailing list