From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:40324) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1exte4-0002EM-N3 for qemu-devel@nongnu.org; Mon, 19 Mar 2018 08:12:14 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1exte1-0002bV-IV for qemu-devel@nongnu.org; Mon, 19 Mar 2018 08:12:08 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:53404 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 1exte1-0002aZ-E5 for qemu-devel@nongnu.org; Mon, 19 Mar 2018 08:12:05 -0400 Date: Mon, 19 Mar 2018 12:11:47 +0000 From: "Dr. David Alan Gilbert" Message-ID: <20180319121147.GC3206@work-vm> References: <20180313075739.11194-1-xiaoguangrong@tencent.com> <20180313075739.11194-2-xiaoguangrong@tencent.com> <20180315102501.GA3062@work-vm> <423c901d-16b6-67fb-262b-3021e30871ec@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <423c901d-16b6-67fb-262b-3021e30871ec@gmail.com> Subject: Re: [Qemu-devel] [PATCH 1/8] migration: stop compressing page in migration thread List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Xiao Guangrong Cc: pbonzini@redhat.com, mst@redhat.com, mtosatti@redhat.com, quintela@redhat.com, liang.z.li@intel.com, Xiao Guangrong , qemu-devel@nongnu.org, kvm@vger.kernel.org * Xiao Guangrong (guangrong.xiao@gmail.com) wrote: > > Hi David, > > Thanks for your review. > > On 03/15/2018 06:25 PM, Dr. David Alan Gilbert wrote: > > > > migration/ram.c | 32 ++++++++++++++++---------------- > > > > Hi, > > Do you have some performance numbers to show this helps? Were those > > taken on a normal system or were they taken with one of the compression > > accelerators (which I think the compression migration was designed for)? > > Yes, i have tested it on my desktop, i7-4790 + 16G, by locally live migrate > the VM which has 8 vCPUs + 6G memory and the max-bandwidth is limited to 350. > > During the migration, a workload which has 8 threads repeatedly written total > 6G memory in the VM. Before this patchset, its bandwidth is ~25 mbps, after > applying, the bandwidth is ~50 mbps. OK, that's good - worth adding those notes to your cover letter. I wonder how well it works with compression acceleration hardware; I can't see anything in this series making it worse. > BTW, Compression will use almost all valid bandwidth after all of our work > which i will post it out part by part. Oh, that will be very nice. Dave -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK