From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:54275) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UUNqz-0002gb-T4 for qemu-devel@nongnu.org; Mon, 22 Apr 2013 17:00:52 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UUNqx-0004N2-5k for qemu-devel@nongnu.org; Mon, 22 Apr 2013 17:00:49 -0400 Received: from e9.ny.us.ibm.com ([32.97.182.139]:35770) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UUNqx-0004Mw-2c for qemu-devel@nongnu.org; Mon, 22 Apr 2013 17:00:47 -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 ; Mon, 22 Apr 2013 17:00:46 -0400 Received: from d01relay05.pok.ibm.com (d01relay05.pok.ibm.com [9.56.227.237]) by d01dlp02.pok.ibm.com (Postfix) with ESMTP id 0BED86E803A for ; Mon, 22 Apr 2013 17:00:42 -0400 (EDT) Received: from d03av01.boulder.ibm.com (d03av01.boulder.ibm.com [9.17.195.167]) by d01relay05.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r3ML0iIn315704 for ; Mon, 22 Apr 2013 17:00:44 -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 r3MKxen9018991 for ; Mon, 22 Apr 2013 14:59:41 -0600 Message-ID: <5175A4BA.3060706@linux.vnet.ibm.com> Date: Mon, 22 Apr 2013 16:59:38 -0400 From: "Michael R. Hines" MIME-Version: 1.0 References: <1366579081-6857-1-git-send-email-mrhines@linux.vnet.ibm.com> <1366579081-6857-11-git-send-email-mrhines@linux.vnet.ibm.com> <51759C91.9030008@redhat.com> In-Reply-To: <51759C91.9030008@redhat.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v5 10/12] rdma: introduce capability x-rdma-pin-all List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Eric Blake Cc: aliguori@us.ibm.com, quintela@redhat.com, qemu-devel@nongnu.org, owasserm@redhat.com, abali@us.ibm.com, mrhines@us.ibm.com, gokul@us.ibm.com, pbonzini@redhat.com On 04/22/2013 04:24 PM, Eric Blake wrote: > On 04/21/2013 03:17 PM, mrhines@linux.vnet.ibm.com wrote: >> From: "Michael R. Hines" >> >> This capability allows you to disable dynamic chunk registration >> for better throughput on high-performance links. >> >> For example, using an 8GB RAM virtual machine with all 8GB of memory in >> active use and the VM itself is completely idle using a 40 gbps infiniband link: >> >> 1. x-pin-all disabled total time: approximately 7.5 seconds @ 9.5 Gbps >> 2. x-pin-all enabled total time: approximately 4 seconds @ 26 Gbps > Naming here doesn't match the actual bit name; but it is obvious enough > to know what you meant. > > Thanks for doing this, by the way - the default-to-disabled is a bit > nicer to manage from libvirt's perspective. > >> These numbers would of course scale up to whatever size virtual machine >> you have to migrate using RDMA. >> >> Enabling this feature does *not* have any measurable affect on >> migration *downtime*. This is because, without this feature, all of the >> memory will have already been registered already in advance during >> the bulk round and does not need to be re-registered during the successive >> iteration rounds. >> >> Signed-off-by: Michael R. Hines >> --- >> include/migration/migration.h | 2 ++ >> migration.c | 9 +++++++++ >> qapi-schema.json | 7 ++++++- >> 3 files changed, 17 insertions(+), 1 deletion(-) > >> +++ b/qapi-schema.json >> @@ -602,10 +602,15 @@ >> # This feature allows us to minimize migration traffic for certain work >> # loads, by sending compressed difference of the pages >> # >> +# @x-rdma-pin-all: (since 1.5) Controls whether or not the entire VM memory footprint is > Trailing whitespace, and line longer than 80 columns. You ought to > rewrap this, and make sure it passes checkpatch.pl. > > But since that is whitespace-only, feel free to add: > > Reviewed-by: Eric Blake > Acknowledged.