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-devel

RE: [Xen-devel] Re: [PATCH 1/4] CPU online/offline support in Xen

To: "Keir Fraser" <keir.fraser@xxxxxxxxxxxxx>, "Shan, Haitao" <haitao.shan@xxxxxxxxx>, "Haitao Shan" <maillists.shan@xxxxxxxxx>
Subject: RE: [Xen-devel] Re: [PATCH 1/4] CPU online/offline support in Xen
From: "Tian, Kevin" <kevin.tian@xxxxxxxxx>
Date: Fri, 12 Sep 2008 14:04:24 +0800
Cc: xen-devel@xxxxxxxxxxxxxxxxxxx, "Wei, Gang" <gang.wei@xxxxxxxxx>
Delivery-date: Thu, 11 Sep 2008 23:05:06 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <C4EFC483.1D197%keir.fraser@xxxxxxxxxxxxx>
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/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
References: <D470B4E54465E3469E2ABBC5AFAC390F024D97B8@xxxxxxxxxxxxxxxxxxxxxxxxxxxx> <C4EFC483.1D197%keir.fraser@xxxxxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
Thread-index: AckUfmQ24tRMYhhpRsGES1HI8UlxdAAHr3OHAAABVNA=
Thread-topic: [Xen-devel] Re: [PATCH 1/4] CPU online/offline support in Xen
>From: Keir Fraser
>Sent: 2008年9月12日 14:02
>To: Tian, Kevin; Shan, Haitao; Haitao Shan
>Cc: xen-devel@xxxxxxxxxxxxxxxxxxx; Wei, Gang
>Subject: Re: [Xen-devel] Re: [PATCH 1/4] CPU online/offline 
>support in Xen
>
>On 12/9/08 03:22, "Tian, Kevin" <kevin.tian@xxxxxxxxx> wrote:
>
>>> I consider this might be a nice win for possibly less effort than is
>> being
>>> expended in trying to make idle residency times (and hence Cx
>> residency
>>> times) as long as possible.
>>> 
>> 
>> These two don't conflict. Cpu online/offline can't be used in small
>> interval due
>> to long latency and added overhead to whole system, but it 
>makes sense
>> when administrator realizes low cpu utilization in a relatively long
>> period like
>> in hrs. Current idle governor instead runs in fine-grained 
>level to fit
>> the otherwise
>> cases.
>
>I certainly agree with that. Just pointing out that, with the 
>fine-graiend
>approach, beyond a certain point you'll be investing effort 
>for smaller and
>smaller further gains.
>

Sure I agree, and beyond that point a weak-designed governor
may even slow system with no actual gain.

Thanks,
Kevin

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

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