From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:41651) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1clLUw-0002Nu-1J for qemu-devel@nongnu.org; Tue, 07 Mar 2017 15:14:19 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1clLUr-0002ss-0H for qemu-devel@nongnu.org; Tue, 07 Mar 2017 15:14:17 -0500 Received: from mail-db5eur01on0100.outbound.protection.outlook.com ([104.47.2.100]:43850 helo=EUR01-DB5-obe.outbound.protection.outlook.com) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1clLUq-0002sQ-Ek for qemu-devel@nongnu.org; Tue, 07 Mar 2017 15:14:12 -0500 References: <20170203152321.19739-1-pbutsykin@virtuozzo.com> <20170214140249.GJ2463@work-vm> <58B92BD6.2030404@virtuozzo.com> <20170307135625.GF2869@work-vm> From: Pavel Butsykin Message-ID: <58BEC6CC.5090905@virtuozzo.com> Date: Tue, 7 Mar 2017 17:42:20 +0300 MIME-Version: 1.0 In-Reply-To: <20170307135625.GF2869@work-vm> Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v2 0/3] migration capability to discard the migrated ram pages List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Dr. David Alan Gilbert" Cc: qemu-devel@nongnu.org, quintela@redhat.com On 07.03.2017 16:56, Dr. David Alan Gilbert wrote: > * Pavel Butsykin (pbutsykin@virtuozzo.com) wrote: >> On 14.02.2017 17:02, Dr. David Alan Gilbert wrote: >>> Hi Pavel, >>> I was curious, having merged this, how you're using postcopy; do you switch >>> into postcopy mode immediately or wait until the first sync or what? >>> Do you find yourself in postcopy mode long enough that it's worth >>> doing the release? If so on what size VMs are you working with? >>> >>> Dave >> >> Hi Dave, >> I'm sorry it took so long, I was on vacation. And thanks for the quick >> review and merge! >> >> We want to use this function to update Qemu without rebooting VMs. It >> looks like a local migration on the same host. Now, switching into >> postcopy mode is done immediately, the size of VMs can be very >> different. > > Thanks! Do you have libvirt magic to do that update? Yes, there are patches that add a flag "--local" for migration. The flag adds start incoming VM and other magic about replacement source on destination. > Dave > >>> * Pavel Butsykin (pbutsykin@virtuozzo.com) wrote: >>>> This feature frees the migrated memory on the source during postcopy-ram >>>> migration. In the second step of postcopy-ram migration when the source vm >>>> is put on pause we can free unnecessary memory. It will allow, in particular, >>>> to start relaxing the memory stress on the source host in a load-balancing >>>> scenario. >>>> >>>> Changes from v1: >>>> - changed name of the interfaces (discard to release) >>>> - fix make check error >>>> - add more comments to qemu_iovec_release_ram() >>>> - rebase on "Postcopy: Hugepage support" (David's patch series) >>>> - removed ram_discard_page for xbzrle >>>> - fix erroneous release memory in complete precopy (tie release-ram to postcopy) >>>> >>>> Pavel Butsykin (3): >>>> migration: add MigrationState arg for ram_save_/compressed_/page() >>>> add 'release-ram' migrate capability >>>> migration: discard non-dirty ram pages after the start of postcopy >>>> >>>> include/migration/migration.h | 2 ++ >>>> include/migration/qemu-file.h | 3 ++- >>>> migration/migration.c | 13 ++++++++++ >>>> migration/qemu-file.c | 59 ++++++++++++++++++++++++++++++++++++++----- >>>> migration/ram.c | 56 ++++++++++++++++++++++++++++++++++------ >>>> qapi-schema.json | 5 +++- >>>> 6 files changed, 121 insertions(+), 17 deletions(-) >>>> >>>> -- >>>> 2.11.0 >>>> >>>> >>> -- >>> Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK >>> > -- > Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK >