From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:40809) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Zud23-0002fd-L3 for qemu-devel@nongnu.org; Fri, 06 Nov 2015 04:10:04 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Zud20-0000d4-DZ for qemu-devel@nongnu.org; Fri, 06 Nov 2015 04:10:03 -0500 Received: from mx1.redhat.com ([209.132.183.28]:53715) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Zud20-0000cz-5x for qemu-devel@nongnu.org; Fri, 06 Nov 2015 04:10:00 -0500 Date: Fri, 6 Nov 2015 09:09:53 +0000 From: "Dr. David Alan Gilbert" Message-ID: <20151106090952.GA2459@work-vm> References: <1446747083-18205-1-git-send-email-dgilbert@redhat.com> <20151106034846.GC29481@in.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20151106034846.GC29481@in.ibm.com> Subject: Re: [Qemu-devel] [PATCH v9 00/56] Postcopy implementation List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Bharata B Rao Cc: aarcange@redhat.com, yamahata@private.email.ne.jp, quintela@redhat.com, liang.z.li@intel.com, qemu-devel@nongnu.org, luis@cs.umu.se, amit.shah@redhat.com, pbonzini@redhat.com, david@gibson.dropbear.id.au * Bharata B Rao (bharata@linux.vnet.ibm.com) wrote: > On Thu, Nov 05, 2015 at 06:10:27PM +0000, Dr. David Alan Gilbert (git) wrote: > > From: "Dr. David Alan Gilbert" > > > > This is the 9th cut of my version of postcopy. > > > > The userfaultfd linux kernel code is now in the upstream kernel > > tree, and so 4.3 can be used without modification. > > > > This qemu series can be found at: > > https://github.com/orbitfp7/qemu.git > > on the wp3-postcopy-v9 tag > > > > Testing status: > > * Tested heavily on x86 > > * Smoke tested on aarch64 (so it does work on different page sizes) > > Tested minimally on ppc64 with back and forth postcopy migration of > unloaded pseries guest within the localhost - works as expected. > > However I am seeing a failure in one case. I am not sure if this is > a user error or a real issue in postcopy migration. If I switch to postcopy > migration immediately after starting the migration, I see the migration > failing with error: > > qemu-system-ppc64: qemu_savevm_send_packaged: Unreasonably large packaged state: 25905005 I put an arbitrary limit of 16MB (see MAX_VM_CMD_PACKAGED_SIZE in include/sysemu/sysemu.h) on the size of the data accepted into the packaged blob. How big is the htab data likely to be? Dave > 1. (qemu) migrate_set_capability x-postcopy-ram on > > 2. (qemu) migrate -d tcp:localhost:4444 > > 3. (qemu) info migrate > capabilities: xbzrle: off rdma-pin-all: off auto-converge: off zero-blocks: off compress: off events: off x-postcopy-ram: on > Migration status: active > total time: 4177 milliseconds > expected downtime: 300 milliseconds > setup: 75 milliseconds > transferred ram: 115523 kbytes > throughput: 155.69 mbps > remaining ram: 30117196 kbytes > total ram: 33554688 kbytes > duplicate: 835311 pages > skipped: 0 pages > normal: 24061 pages > normal bytes: 96244 kbytes > dirty sync count: 1 > > 4. (qemu) migrate_start_postcopy > > 5. (qemu) info migrate > capabilities: xbzrle: off rdma-pin-all: off auto-converge: off zero-blocks: off compress: off events: off x-postcopy-ram: on > Migration status: failed > total time: 0 milliseconds > > If I run 'info migrate' in step 3 a few more times before step 4, then > the migration succeeds. So is there a way to figure out when to switch > over to postcopy migration ? > > QEMU cmdline: ./ppc64-softmmu/qemu-system-ppc64 --enable-kvm --nographic -vga none -machine pseries -m 32G,slots=32,maxmem=64G -smp 16 -device virtio-blk-pci,drive=rootdisk -drive file=/home/bharata/F20-snap1,if=none,cache=none,id=rootdisk,format=qcow2 -monitor telnet:127.0.0.1:1234,server,nowait > > Host: 4.3.0-rc7+ > > Regards, > Bharata. > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK