From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:42656) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UHyEP-0006J2-2R for qemu-devel@nongnu.org; Tue, 19 Mar 2013 11:13:47 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UHyEK-000570-NO for qemu-devel@nongnu.org; Tue, 19 Mar 2013 11:13:40 -0400 Received: from e8.ny.us.ibm.com ([32.97.182.138]:35998) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UHyEK-00056t-F5 for qemu-devel@nongnu.org; Tue, 19 Mar 2013 11:13:36 -0400 Received: from /spool/local by e8.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 19 Mar 2013 11:13:35 -0400 Received: from d01relay02.pok.ibm.com (d01relay02.pok.ibm.com [9.56.227.234]) by d01dlp03.pok.ibm.com (Postfix) with ESMTP id 36B63C90072 for ; Tue, 19 Mar 2013 11:13:30 -0400 (EDT) Received: from d03av01.boulder.ibm.com (d03av01.boulder.ibm.com [9.17.195.167]) by d01relay02.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r2JFDRbE235664 for ; Tue, 19 Mar 2013 11:13:28 -0400 Received: from d03av01.boulder.ibm.com (loopback [127.0.0.1]) by d03av01.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id r2JFCs3t010551 for ; Tue, 19 Mar 2013 09:12:54 -0600 Message-ID: <51488072.5070208@linux.vnet.ibm.com> Date: Tue, 19 Mar 2013 11:12:50 -0400 From: "Michael R. Hines" MIME-Version: 1.0 References: <1363576743-6146-1-git-send-email-mrhines@linux.vnet.ibm.com> <1363576743-6146-9-git-send-email-mrhines@linux.vnet.ibm.com> <5146D9BF.3030407@redhat.com> <51477A26.8090600@linux.vnet.ibm.com> <51482D78.3010301@redhat.com> <5148643F.2070401@linux.vnet.ibm.com> <51486733.7060207@redhat.com> <51486AD0.80309@linux.vnet.ibm.com> <51486C0D.2040609@redhat.com> <514871C2.5020108@linux.vnet.ibm.com> <5148748C.5050509@redhat.com> <51487DF4.9080601@linux.vnet.ibm.com> In-Reply-To: <51487DF4.9080601@linux.vnet.ibm.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [Bug]? (RDMA-related) ballooned memory not consulted during migration? List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paolo Bonzini Cc: aliguori@us.ibm.com, mst@redhat.com, qemu-devel@nongnu.org, owasserm@redhat.com, abali@us.ibm.com, mrhines@us.ibm.com, gokul@us.ibm.com Actually, you don't even need ballooning to reproduce this behavior. Is this a known issue? - Michael On 03/19/2013 11:02 AM, Michael R. Hines wrote: > Consider the following sequence: > > 1. Boot fresh VM (say, a boring 1GB vm) => Resident > set is small, say 100M > 2. Touch all the memory (with a utility or something) => Resident set > is ~1G > 3. Send QMP "balloon 500" => Resident set is ~500M > 4. Now, migrate the VM => Resident set is 1G again > > This suggests to me that migration is not accounting for > what memory was ballooned. > > I suspect this is because the migration_bitmap does not coordinate > with the list of ballooned-out memory that was MADVISED(). > > This affects RDMA as well as TCP on the sender side. > > Is there any hard reason why we're not validating migration_bitmap > against > the memory that was MADVISED()'d? > > - Michael R. Hines > >