From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:52726) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fYvqq-0004de-1H for qemu-devel@nongnu.org; Fri, 29 Jun 2018 12:02:25 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fYvqm-00047x-VG for qemu-devel@nongnu.org; Fri, 29 Jun 2018 12:02:24 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:49288 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fYvqm-00045S-Qo for qemu-devel@nongnu.org; Fri, 29 Jun 2018 12:02:20 -0400 References: <20180629080320.320144-1-dplotnikov@virtuozzo.com> <20180629080320.320144-2-dplotnikov@virtuozzo.com> From: Eric Blake Message-ID: <1a933047-a140-67a3-594a-dab4b28c1a83@redhat.com> Date: Fri, 29 Jun 2018 11:02:19 -0500 MIME-Version: 1.0 In-Reply-To: <20180629080320.320144-2-dplotnikov@virtuozzo.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v0 1/7] migration: add background snapshot capability List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Denis Plotnikov , dgilbert@redhat.com, quintela@redhat.com, pbonzini@redhat.com Cc: qemu-devel@nongnu.org On 06/29/2018 03:03 AM, Denis Plotnikov wrote: > The capability is used for the background vmstate saving > using the migration infrastructure. > Background vmstate saving means that the majority of vmstate > (RAM) is saved in the background when VM's vCPUS are running. > This helps to reduce the VM downtime on VM snapshotting. > > Signed-off-by: Denis Plotnikov > --- > migration/migration.c | 35 +++++++++++++++++++++++++++++++++++ > migration/migration.h | 1 + > qapi/migration.json | 6 +++++- > 3 files changed, 41 insertions(+), 1 deletion(-) > > +++ b/qapi/migration.json > @@ -352,12 +352,16 @@ > # > # @x-multifd: Use more than one fd for migration (since 2.11) > # > +# @background-snapshot: Using migration infrastructure makes VM snapshot > +# saving its RAM in background. This reduces VM downtime. (since 2.12) You've missed 2.12; the next release is 3.0 (and even then, we're fast coming up on soft freeze, so a maintainer must be willing to take this feature soon, or it will become 3.1 material). -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3266 Virtualization: qemu.org | libvirt.org