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Message-ID: <47C712EF.1060703@goop.org>
Date:	Thu, 28 Feb 2008 12:00:47 -0800
From:	Jeremy Fitzhardinge <jeremy@...p.org>
To:	"Christopher S. Aker" <caker@...shore.net>
CC:	virtualization@...ts.linux-foundation.org,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	Xen-devel <xen-devel@...ts.xensource.com>
Subject: Re: Xen paravirt frontend block hang

Christopher S. Aker wrote:
> Sorry for the noise if this isn't the appropriate venue for this.  I 
> posted this last month to xen-devel:
>
> http://lists.xensource.com/archives/html/xen-devel/2007-11/msg00777.html
>
> I can reliably cause a paravirt_ops Xen guest to hang during intensive 
> IO.  My current recipe is an untar/tar loop, without compression, of a 
> kernel tree.  For example:
>
> wget http://kernel.org/pub/linux/kernel/v2.6/linux-2.6.23.tar.bz2
> bzip2 -d linux-2.6.23.tar.bz2
>
> while true;
>   echo `date`
>   tar xf linux-2.6.23.tar
>   tar cf linux-2.6.23.tar linux-2.6.23
> done
>
> After a few loops, anything that touches the xvd device that hung will 
> get stuck in D state.

I've been running this all night without seeing any problem.  I'm using 
current x86.git#testing with a few local patches, but nothing especially 
relevent-looking.

Could you try the attached patch to see if it makes any difference?

    J

>
> This happens on both a 2.6.16 and 2.6.18 dom0 (3.1.2 tools).  Paravirt 
> guests I've tried that exhibit the problem: 2.6.23.8, 2.6.23.12, and 
> 2.6.24-rc6.  It does *not* occur using the Xensource 2.6.18 domU tree 
> from 3.1.2.  In all cases, the host continues to run fine, nothing out 
> of the ordinary is logged on the dom0 side, xenstore reports the 
> status of the devices is fine.
>
> Can anyone reproduce this problem, or let me know what else I can 
> provide to help track this down?
>
> Thanks,
> -Chris
> _______________________________________________
> Virtualization mailing list
> Virtualization@...ts.linux-foundation.org
> https://lists.linux-foundation.org/mailman/listinfo/virtualization

View attachment "xen-indirect-iret.patch" of type "text/x-patch" (2430 bytes)

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