From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:46762) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cjizC-0002wl-VY for qemu-devel@nongnu.org; Fri, 03 Mar 2017 03:54:52 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cjiz9-0003J5-SK for qemu-devel@nongnu.org; Fri, 03 Mar 2017 03:54:51 -0500 Received: from mail-db5eur01on0119.outbound.protection.outlook.com ([104.47.2.119]:42432 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 1cjiz9-0003Hq-8p for qemu-devel@nongnu.org; Fri, 03 Mar 2017 03:54:47 -0500 References: <20170203152321.19739-1-pbutsykin@virtuozzo.com> <20170214140249.GJ2463@work-vm> From: Pavel Butsykin Message-ID: <58B92BD6.2030404@virtuozzo.com> Date: Fri, 3 Mar 2017 11:39:50 +0300 MIME-Version: 1.0 In-Reply-To: <20170214140249.GJ2463@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 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. > * 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 >