Subject: Re: "blocked" domUs
To: david l goodrich <dlg@dsrw.org>
From: Manuel Bouyer <bouyer@antioche.eu.org>
List: port-xen
Date: 04/09/2007 12:17:40
On Sun, Apr 08, 2007 at 11:19:10PM -0500, david l goodrich wrote:
> On Fri, Apr 06, 2007 at 07:53:27PM -0500, david l goodrich wrote:
> > On Wed, Apr 04, 2007 at 08:30:43PM -0500, david l goodrich wrote:
> > > Performance of the domUs on my Pentium D 3ghz dom0 is pretty
> > > poor - for example, ssh'ing from a domU occasionally just pauses
> > > and cpu utilization on the domu goes down to 0.  No discernible
> > > reason that I can see.
> > > 
> > 
> > Even communication between domUs on this computer is affected by
> > this.  AFS fileservers on this dom0 are nigh unusable, volume
> > moves are failing left and right as the domUs simply stop
> > processing.
> > 
> > Does anyone have some insight into this?
> 
> Well, if no-one else does, I do.
> 
> Booting the computer in single-processor mode (disabling SMP and
> ioapic and ACPI) solves the problem.
> 
> Good enough, I'm sick of dealing with it.
> 
> Clearly, NetBSD is not ready for prime-time when it comes to SMP.

I have several Xen systems on SMP hosts (from old dual-CPU P2 to brand new
dual-CPU dual-core hyperthreaded systems) with NetBSD as dom0. They work
fine; and in fact NetBSD doesn't care it the host is UP or SMP, all
the work is done by Xen. To me it looks more like it's Xen which
has troubles on this hardware ...

-- 
Manuel Bouyer <bouyer@antioche.eu.org>
     NetBSD: 26 ans d'experience feront toujours la difference
--