Xen 
 
Home About Xen.org Xen Xen Summit Wiki Mailing List Bug Tracker Xen Downloads
 
   
 

xen-devel

Re: [Xen-devel] [PATCH][Retry 1] 4/4: cpufreq/PowerNow! in Xen: PowerNow

To: "Langsdorf, Mark" <mark.langsdorf@xxxxxxx>, <xen-devel@xxxxxxxxxxxxxxxxxxx>
Subject: Re: [Xen-devel] [PATCH][Retry 1] 4/4: cpufreq/PowerNow! in Xen: PowerNow! changes
From: Keir Fraser <Keir.Fraser@xxxxxxxxxxxx>
Date: Fri, 31 Aug 2007 18:44:55 +0100
Delivery-date: Fri, 31 Aug 2007 10:41:04 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxx
In-reply-to: <1449F58C868D8D4E9C72945771150BDF0207700E@xxxxxxxxxxxxxxxxx>
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/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
Thread-index: Acfr5NmmGClNJFfYEdySawAX8io7RQACpUAwAAHNWSM=
Thread-topic: [Xen-devel] [PATCH][Retry 1] 4/4: cpufreq/PowerNow! in Xen: PowerNow! changes
User-agent: Microsoft-Entourage/11.3.3.061214
On 31/8/07 17:56, "Langsdorf, Mark" <mark.langsdorf@xxxxxxx> wrote:

>> Should we have a copy of that file in powernow-k8-xen.c? Can
>> the patched file work correctly in a native Linux build?
> 
> The patch is the same patch I submitted upstream for the native
> 2.6.23 Linux kernel.
> 
> In native mode, the kernel creates a cpumask for each cpu that
> lists its sibling cores.  Unfortunately, Xen doesn't do that.
> The patch instead reads and parses the _PSD ACPI structure,
> which indicates which cores share pstates with other cores.
> (Frankly, _PSD is the right way to do it, but the other way
> was easier until Linux got ACPI support for _PSD).  If Xen
> were using the same kernel version as Linux, the patch wouldn't
> be necessary.

Okay, that was the other possibility. :-) Fine then!

 -- Keir



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