From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:53034) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UIKqr-0006XE-Jf for qemu-devel@nongnu.org; Wed, 20 Mar 2013 11:22:56 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UIKqo-0002oY-Jb for qemu-devel@nongnu.org; Wed, 20 Mar 2013 11:22:53 -0400 Received: from e9.ny.us.ibm.com ([32.97.182.139]:42497) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UIKqo-0002oL-FL for qemu-devel@nongnu.org; Wed, 20 Mar 2013 11:22:50 -0400 Received: from /spool/local by e9.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 20 Mar 2013 11:22:48 -0400 Received: from d01relay06.pok.ibm.com (d01relay06.pok.ibm.com [9.56.227.116]) by d01dlp02.pok.ibm.com (Postfix) with ESMTP id C0D6E6E807F for ; Wed, 20 Mar 2013 11:22:38 -0400 (EDT) Received: from d03av06.boulder.ibm.com (d03av06.boulder.ibm.com [9.17.195.245]) by d01relay06.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r2KFMeov28442638 for ; Wed, 20 Mar 2013 11:22:40 -0400 Received: from d03av06.boulder.ibm.com (loopback [127.0.0.1]) by d03av06.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id r2KFPGGi007991 for ; Wed, 20 Mar 2013 09:25:17 -0600 Message-ID: <5149D43C.3060305@linux.vnet.ibm.com> Date: Wed, 20 Mar 2013 11:22:36 -0400 From: "Michael R. Hines" MIME-Version: 1.0 References: <5147A209.80202@linux.vnet.ibm.com> <20130319081939.GC11259@redhat.com> <51487F68.2060305@linux.vnet.ibm.com> <20130319151606.GA13649@redhat.com> <51488521.4010909@linux.vnet.ibm.com> <20130319153658.GA14317@redhat.com> <51489BC3.3030504@linux.vnet.ibm.com> <51489D05.2000400@redhat.com> <5148A2F6.1070206@linux.vnet.ibm.com> <5148A5FB.1000209@redhat.com> <20130320130754.GA9777@redhat.com> <5149D2A4.2070106@linux.vnet.ibm.com> In-Reply-To: <5149D2A4.2070106@linux.vnet.ibm.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [RFC PATCH RDMA support v4: 03/10] more verbose documentation of the RDMA transport List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Michael S. Tsirkin" Cc: aliguori@us.ibm.com, qemu-devel@nongnu.org, owasserm@redhat.com, abali@us.ibm.com, mrhines@us.ibm.com, gokul@us.ibm.com, Paolo Bonzini s / is page mapped?/ is page unmapped?/ g On 03/20/2013 11:15 AM, Michael R. Hines wrote: > OK, can we make a deal? =) > > I'm willing to put in the work to perform the dynamic registration on > the destination side, > but let's go a step further and piggy-back on the effort: > > We need to couple this registration with a very small modification to > save_ram_block(): > > Currently, save_ram_block does: > > 1. is RDMA turned on? if yes, unconditionally add to next chunk > (will be made to dynamically > register on destination) > 2. is_dup_page() ? if yes, skip > 3. in xbzrle cache? if yes, skip > 4. still not sent? if yes, transmit > > I propose adding a "stub" function that adds: > > 0. is page mapped? if yes, skip (always returns true for now) > 1. same > 2. same > 3. same > 4. same > > Then, later, in a separate patch, I can implement /dev/pagemap support. > > When that's done, RDMA dynamic registration will actually take effect and > benefit from actually verifying that the page is mapped or not. > > - Michael > > > On 03/20/2013 09:07 AM, Michael S. Tsirkin wrote: >> My problem is with the protocol. If it assumes at the protocol level >> that everything is pinned down on the destination, we'll have to >> rework it all to make it really useful. > >