WARNING - OLD ARCHIVES

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/
   
 
 
Xen 
 
Home Products Support Community News
 
   
 

xen-users

Re: [Xen-users] Re: Status of frequency scaling

To: xen-users@xxxxxxxxxxxxxxxxxxx
Subject: Re: [Xen-users] Re: Status of frequency scaling
From: Goswin von Brederlow <brederlo@xxxxxxxxxxxxxxxxxxxxxxxxxxx>
Date: Wed, 02 May 2007 10:08:45 +0200
Delivery-date: Wed, 02 May 2007 01:07:27 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxx
In-reply-to: <20070430T1347.GA.b4594.stse@xxxxxxxxxxxxxxxxxxx> (Stephan Seitz's message of "Mon, 30 Apr 2007 13:55:21 +0200")
List-help: <mailto:xen-users-request@lists.xensource.com?subject=help>
List-id: Xen user discussion <xen-users.lists.xensource.com>
List-post: <mailto:xen-users@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-users>, <mailto:xen-users-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-users>, <mailto:xen-users-request@lists.xensource.com?subject=unsubscribe>
References: <20070428T2219.GA.c5923.stse@xxxxxxxxxxxxxxxxxxx> <907625E08839C4409CE5768403633E0B018E1C70@xxxxxxxxxxxxxxxxx> <20070430T1347.GA.b4594.stse@xxxxxxxxxxxxxxxxxxx>
Sender: xen-users-bounces@xxxxxxxxxxxxxxxxxxx
User-agent: Gnus/5.110006 (No Gnus v0.6) XEmacs/21.4.19 (linux)
Stephan Seitz <nur-ab-sal@xxxxxx> writes:

> On Mon, Apr 30, 2007 at 11:47:03AM +0200, Petersson, Mats wrote:
>> Well, the current official status is "it doesn't work at all".
>
> Hm, okay.
>
>>There are several problems, some of which are relatively easy to fix and
>>some that aren't:
>>2. There is no power-management policy for the entire system, so dom0
>>usage will determine the entire system's performance. This doesn't work
>> very well, as Dom0 isn't supposed to be heavily loaded, DomU's are.
>
> Understandable. In my case, Dom0 would be by Desktop system while DomU
> would be the firewall (for now a different host), so I could live with
> this restriction.

It shouldn't be too hard to write a userspace governor that check the
cpu usage of all domains (like xentop does) and then scales the
frequency to match.

I have xen on my laptop and the batery live goes down drastically
without frequency scaling (understandably). I would like to have at
least manual control so I can turn the CPU down when on batery.

>>3. Guest may need to be informed of the frequency change. Some kernels
>>may not appreciate that the CPU frequency is chaning "without it's
>>knowledge". [This is probably not a big problem on modern OS's, but some
>> older ones may be very un-co-operative on this account].
>
> Ah yes, I remember, that a Solaris system within VMware server
> didnâ??t like the frequency changes of the Linux host.
> I donâ??t have any problems with XP within VMware server at my notebook.

Does Linux care?

>>> I have an AMD64. powerno-k8 works find with non-XEN kernels, but
>>> with XEN-kernels I get the error:
>>>
>>> powernow-k8: Found 1 AMD Athlon(tm) 64 Processor 3400+ processors
>>> (version 2.00.00)
>>> powernow-k8: BIOS error - no PSB or ACPI _PSS objects
>>This is strange - as far as I can remember, I had powernow working on my
>>machine not so long ago (3.0.4 or so) with only the traps.c patched to
>> allow writing of the FID/VID controls registers.
>
> Could you send me the patch for traps.c? I would like to try it.

Me too.

MfG
        Goswin

_______________________________________________
Xen-users mailing list
Xen-users@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-users

<Prev in Thread] Current Thread [Next in Thread>