From mboxrd@z Thu Jan  1 00:00:00 1970
From: Ross Boylan <ross@biostat.ucsf.edu>
Subject: Re: XP smp using a lot of CPU
Date: Thu, 14 May 2009 08:40:40 -0700
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Cc: ross@biostat.ucsf.edu, kvm@vger.kernel.org
To: Johannes Schlatow <johannes.schlatow@gmx.de>
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On Thu, 2009-05-14 at 12:19 +0200, Johannes Schlatow wrote:
> I had a similar problem some weeks ago. Finally I found out that my VM
> running WinXP was working on a non-acpi system (maybe I started kvm
> with -no-acpi option during the installation). In the Device Manager
> there has to be the entry Computer->"ACPI Multiprocessor PC".
> Otherwise the VM produced 100% real cpu load on my machines (the fans
> were running on highest speed level).
> I just started the WinXP installation in repair mode and this did fix
> the problem.
> 
> I hope this helps!
> 
> regards
>   Johannes
That may be it: I was running with -no-acpi.  Various docs recommended
this for Windows performance, but your comment reminded me that acpi is
(I think) required for multiprocessors.

I'll be in where I can check on this later today.

Thanks.
Ross
> 
> On Wed, May 13, 2009 at 2:41 AM, Ross Boylan <ross@biostat.ucsf.edu>
> wrote:
>         I just installed XP into a new VM, specifying -smp 2 for the
>         machine.
>         According to top, it's using nearly 200% of a cpu even when
>         I'm not
>         doing anything.
>         
>         Is this real CPU useage, or just a reporting problem (just as
>         my disk
>         image is big according to ls, but isn't really)?
>         
>         If it's real, is there anything I can do about it?
>         
>         kvm 0.7.2 on Debian Lenny (but 2.6.29 kernel), amd64.  Xeon
>         chips; 32
>         bit version of XP pro installed, now fully patched (including
>         the
>         Windows Genuine Advantage stuff, though I cancelled it when it
>         wanted to
>         run).
>         
>         Task manager in XP shows virtually no CPU useage.
>         
>         Please cc me on responses.
>         
>         Thanks for any assistance.
>         --
>         Ross Boylan                                      wk:  (415)
>         514-8146
>         185 Berry St #5700
>         ross@biostat.ucsf.edu
>         Dept of Epidemiology and Biostatistics           fax: (415)
>         514-8150
>         University of California, San Francisco
>         San Francisco, CA 94107-1739                     hm:  (415)
>         550-1062
>         
>         --
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