Re: [Xen-devel] Cpu pools discussion

To:	Keir Fraser <keir.fraser@xxxxxxxxxxxxx>
Subject:	Re: [Xen-devel] Cpu pools discussion
From:	Juergen Gross <juergen.gross@xxxxxxxxxxxxxx>
Date:	Thu, 30 Jul 2009 10:58:16 +0200
Cc:	Tim Deegan <Tim.Deegan@xxxxxxxxxxxxx>, George Dunlap <dunlapg@xxxxxxxxx>, Zhigang Wang <zhigang.x.wang@xxxxxxxxxx>, "xen-devel@xxxxxxxxxxxxxxxxxxx" <xen-devel@xxxxxxxxxxxxxxxxxxx>
Delivery-date:	Thu, 30 Jul 2009 01:59:08 -0700
Dkim-signature:	v=1; a=rsa-sha256; c=simple/simple; d=ts.fujitsu.com; i=juergen.gross@xxxxxxxxxxxxxx; q=dns/txt; s=s1536b; t=1248944423; x=1280480423; h=from:sender:reply-to:subject:date:message-id:to:cc: mime-version:content-transfer-encoding:content-id: content-description:resent-date:resent-from:resent-sender: resent-to:resent-cc:resent-message-id:in-reply-to: references:list-id:list-help:list-unsubscribe: list-subscribe:list-post:list-owner:list-archive; z=From:=20Juergen=20Gross=20<juergen.gross@xxxxxxxxxxxxxx> \|Subject:=20Re:=20[Xen-devel]=20Cpu=20pools=20discussion \|Date:=20Thu,=2030=20Jul=202009=2010:58:16=20+0200 \|Message-ID:=20<4A7160A8.1000105@xxxxxxxxxxxxxx>\|To:=20Ke ir=20Fraser=20<keir.fraser@xxxxxxxxxxxxx>\|CC:=20Tim=20Dee gan=20<Tim.Deegan@xxxxxxxxxxxxx>,=20=0D=0A=20George=20Dun lap=20<dunlapg@xxxxxxxxx>,=0D=0A=20Zhigang=20Wang=20<zhig ang.x.wang@xxxxxxxxxx>,=20=0D=0A=20"xen-devel@xxxxxxxxxxx urce.com"=20<xen-devel@xxxxxxxxxxxxxxxxxxx>\|MIME-Version: =201.0\|Content-Transfer-Encoding:=207bit\|In-Reply-To:=20< C69718AB.10ED3%keir.fraser@xxxxxxxxxxxxx>\|References:=20< C69718AB.10ED3%keir.fraser@xxxxxxxxxxxxx>; bh=qiCh7RGscBQOp/TiVW4Sj0Ide78idd5uCcUqoExAR5Y=; b=i9vn4cFgnkHl51iTOmfXc9i435WNKpZKmMaVkRZG5q3l5GasHtY+Inrd kOE0bswm6tuExdIHZgVGA02Lutu990/z26DQ4qpyFHThgAgAsQaa7haXx /Am9sVnEuvkCXs1DkIGp+v0sSJld3K/IYhr2MoVZwyqit7FA06V8sP8+r YN+4bGWRAO9HzsZ+YXTmzPZTWXn8pqQMbokmmm9arTqunHuO7zh28HKU0 dE1oliKCtw/2+c7IXh2niaWJVNxVC;
Domainkey-signature:	s=s1536a; d=ts.fujitsu.com; c=nofws; q=dns; h=X-SBRSScore:X-IronPort-AV:Received:X-IronPort-AV: Received:Received:Message-ID:Date:From:Organization: User-Agent:MIME-Version:To:CC:Subject:References: In-Reply-To:X-Enigmail-Version:Content-Type: Content-Transfer-Encoding; b=Uc4IfjLvQkM5DfIf2UDk9grEfdRr0PfsgJdbKEdLzTqyGy2tUtTuEQXx bULY2PkaDze70yxQsti2720CPdcu/vsRDt4NkO0EHqfIkjS24rRvv7EN+ ktg6WLgd645/jA3waroOdSU523vz1kXGwGGH5deL+IuYmnRVqXRDoYndz X6yPp3oSVcBX3lCbFfEGs02Im/50ASQnBDSu9SjecxhJS93t4vJE6Rkue JeWDqfQAeGMFQaIgqBCwwYx/ujqF4;
Envelope-to:	www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to:	<C69718AB.10ED3%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>
Organization:	Fujitsu Technology Solutions
References:	<C69718AB.10ED3%keir.fraser@xxxxxxxxxxxxx>
Sender:	xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
User-agent:	Mozilla-Thunderbird 2.0.0.22 (X11/20090707)

Keir Fraser wrote:
> CPU hotplug raises a question in relation to cpupools, by the way. What pool
> does a cpu get added to when it is brought online? And what do you do when
> someone offlines a CPU (e.g., especially when it is the last in its pool)?
> In that latter case, have you not considered it, or do you refuse the
> offline, or do you somehow break the pool affinity so that domains belonging
> to it can run elsewhere?

These cases are already covered by my patch.
A new cpu is always added to the "free pool". It can then be assigned to any
pool. Perhaps it would be better to add it to pool 0, but that's a minor
detail, I think.
Offlining the last cpu of a pool with active domains is refused.


Juergen

-- 
Juergen Gross                 Principal Developer Operating Systems
TSP ES&S SWE OS6                       Telephone: +49 (0) 89 636 47950
Fujitsu Technolgy Solutions               e-mail: juergen.gross@xxxxxxxxxxxxxx
Otto-Hahn-Ring 6                        Internet: ts.fujitsu.com
D-81739 Muenchen                 Company details: ts.fujitsu.com/imprint.html

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

WARNING - OLD ARCHIVES

xen-devel

Re: [Xen-devel] Cpu pools discussion