From mboxrd@z Thu Jan 1 00:00:00 1970 From: George Dunlap Subject: Re: [PATCH 2 of 2 RFC] xl: allow for moving the domain's memory when changing vcpu affinity Date: Fri, 6 Jul 2012 15:07:17 +0100 Message-ID: <4FF6F115.1070106@eu.citrix.com> References: <89aba27edf62271a4862.1341568445@Solace> <4FF6DFE5.7060403@eu.citrix.com> <1341581104.32747.43.camel@zakaz.uk.xensource.com> <1341583550.15708.47.camel@Abyss> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1341583550.15708.47.camel@Abyss> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Dario Faggioli Cc: "Zhang, Yang Z" , Andre Przywara , Ian Jackson , Ian Campbell , xen-devel List-Id: xen-devel@lists.xenproject.org On 06/07/12 15:05, Dario Faggioli wrote: > On Fri, 2012-07-06 at 14:25 +0100, Ian Campbell wrote: >> We could do something cleverer for HVM (or hybrid) guests to migrate >> pages while the guest is live but migrating a page under a PV guest's >> feet requires quiescing it in the style of a migrate. >> > Which, as we're talking about the same host, means reaching a point > where I have two full copies of the guest memory in RAM, or not? > > (Just trying to figure out if I understood things sensibly). No, you can do batches at a time, based on how much free memory you have. If you have enough free memory to keep two copies in RAM at a time, you might as well. But even as little as moving 1MB at a time would probably be easily achievable and not to much overhead. -George