From mboxrd@z Thu Jan 1 00:00:00 1970 From: Juergen Gross Subject: Re: Cpu pools discussion Date: Tue, 28 Jul 2009 15:57:26 +0200 Message-ID: <4A6F03C6.9060603@ts.fujitsu.com> References: <4A6E492D.201@oracle.com> <20090728091929.GI5235@york.uk.xensource.com> <4A6ECFD3.4030709@ts.fujitsu.com> <20090728130701.GJ5235@york.uk.xensource.com> <4A6EFC11.9010404@ts.fujitsu.com> <20090728133134.GK5235@york.uk.xensource.com> <4A6EFFA6.3000405@ts.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: George Dunlap Cc: "xen-devel@lists.xensource.com" , Zhigang Wang , Tim Deegan , Keir Fraser List-Id: xen-devel@lists.xenproject.org George Dunlap wrote: > On Tue, Jul 28, 2009 at 2:39 PM, Juergen > Gross wrote: >> I think your first point is the most important one. >> It might be possible to build a load balancing scheme to shift cpus between >> pools dynamically, but this should be step 2, I think :-) >> But it would be a nice project :-) > > If I recall your use case, Juergen, I thought the whole point was to > keep some set of VMs limited to just a subset of CPUs? So the first > point is a feature for you, not a bug. :-) Indeed. I just like to think about further enhancements, even if my company isn't requiring them... > > If we ever do find someone who wants cpu pools, perhaps to use > different schedulers, but wants to be able to dynamically adjust pool > size, then they can work on such a project. Until then, no point > spending time on something no one's going to use. Absolutely true. OTOH I see pools as an interesting way to support large NUMA systems in an effective way. And for this usage you would need such a project :-) I think it is very important to check the possible future enhancements, as they might influence decisions today. 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@ts.fujitsu.com Otto-Hahn-Ring 6 Internet: ts.fujitsu.com D-81739 Muenchen Company details: ts.fujitsu.com/imprint.html