From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:36386) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1clFbO-0006IK-GZ for qemu-devel@nongnu.org; Tue, 07 Mar 2017 08:56:35 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1clFbL-0001qK-Fn for qemu-devel@nongnu.org; Tue, 07 Mar 2017 08:56:34 -0500 Received: from mx1.redhat.com ([209.132.183.28]:44926) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1clFbL-0001pN-9t for qemu-devel@nongnu.org; Tue, 07 Mar 2017 08:56:31 -0500 Date: Tue, 7 Mar 2017 13:56:25 +0000 From: "Dr. David Alan Gilbert" Message-ID: <20170307135625.GF2869@work-vm> References: <20170203152321.19739-1-pbutsykin@virtuozzo.com> <20170214140249.GJ2463@work-vm> <58B92BD6.2030404@virtuozzo.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <58B92BD6.2030404@virtuozzo.com> 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: Pavel Butsykin Cc: qemu-devel@nongnu.org, quintela@redhat.com * 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? 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