From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: [PATCH v28 0/4] Virtio-balloon: support free page reporting Date: Fri, 9 Feb 2018 05:14:42 +0200 Message-ID: <20180209051212-mutt-send-email-mst@kernel.org> References: <1518083420-11108-1-git-send-email-wei.w.wang@intel.com> <20180208215048-mutt-send-email-mst@kernel.org> <5A7D116B.9070502@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: virtio-dev@lists.oasis-open.org, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, kvm@vger.kernel.org, linux-mm@kvack.org, mhocko@kernel.org, akpm@linux-foundation.org, pbonzini@redhat.com, liliang.opensource@gmail.com, yang.zhang.wz@gmail.com, quan.xu0@gmail.com, nilal@redhat.com, riel@redhat.com, huangzhichao@huawei.com, dgilbert@redhat.com To: Wei Wang Return-path: Sender: List-Post: List-Help: List-Unsubscribe: List-Subscribe: Content-Disposition: inline In-Reply-To: <5A7D116B.9070502@intel.com> List-Id: kvm.vger.kernel.org On Fri, Feb 09, 2018 at 11:11:39AM +0800, Wei Wang wrote: > On 02/09/2018 03:55 AM, Michael S. Tsirkin wrote: > > On Thu, Feb 08, 2018 at 05:50:16PM +0800, Wei Wang wrote: > > > > > Details: > > > Set up a Ping-Pong local live migration, where the guest ceaselessy > > > migrates between the source and destination. Linux compilation, > > > i.e. make bzImage -j4, is performed during the Ping-Pong migration. The > > > legacy case takes 5min14s to finish the compilation. With this > > > optimization patched, it takes 5min12s. > > How is migration time affected in this case? > > > When the linux compilation workload runs, the migration time (both the > legacy and this optimization case) varies as the compilation goes on. It > seems not easy to give a static speedup number, some times the migration > time is reduced to 33%, sometimes to 50%, it varies, and depends on how much > free memory the system has at that moment. For example, at the later stage > of the compilation, I can observe 5GB memory being used as page cache. But > overall, I can observe obvious improvement of the migration time. > > > Best, > Wei You can run multiple tests and give a best, worst and median numbers. -- MST