From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:60093) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eqezh-0001us-I8 for qemu-devel@nongnu.org; Tue, 27 Feb 2018 08:08:38 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eqezd-0008SD-JZ for qemu-devel@nongnu.org; Tue, 27 Feb 2018 08:08:33 -0500 Received: from mail-pf0-x242.google.com ([2607:f8b0:400e:c00::242]:44307) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1eqezd-0008Rr-Cu for qemu-devel@nongnu.org; Tue, 27 Feb 2018 08:08:29 -0500 Received: by mail-pf0-x242.google.com with SMTP id 17so7906230pfw.11 for ; Tue, 27 Feb 2018 05:08:29 -0800 (PST) From: Liang Li Date: Tue, 27 Feb 2018 21:08:22 +0800 Message-ID: <20180227130820.GA11350@localhost> References: <1517915299-15349-1-git-send-email-wei.w.wang@intel.com> <1517915299-15349-4-git-send-email-wei.w.wang@intel.com> <20180209121517.GD2428@work-vm> <5A938E93.5020502@intel.com> <20180227024325-mutt-send-email-mst@kernel.org> <5A952EA7.8010708@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5A952EA7.8010708@intel.com> Subject: Re: [Qemu-devel] [PATCH v2 3/3] virtio-balloon: add a timer to limit the free page report waiting time List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Wei Wang Cc: "Dr. David Alan Gilbert" , qemu-devel@nongnu.org, quintela@redhat.com, pbonzini@redhat.com, liliang.opensource@gmail.com, yang.zhang.wz@gmail.com, quan.xu0@gmail.com, nilal@redhat.com, mst@redhat.com On Tue, Feb 27, 2018 at 06:10:47PM +0800, Wei Wang wrote: > On 02/27/2018 08:50 AM, Michael S. Tsirkin wrote: > > On Mon, Feb 26, 2018 at 12:35:31PM +0800, Wei Wang wrote: > > > On 02/09/2018 08:15 PM, Dr. David Alan Gilbert wrote: > > > > * Wei Wang (wei.w.wang@intel.com) wrote: > > > > I think all this is premature optimization. It is not at all clear that > > anything is gained by delaying migration. Just ask for hints and start > > sending pages immediately. If guest tells us a page is free before it's > > sent, we can skip sending it. OTOH if migration is taking less time to > > complete than it takes for guest to respond, then we are better off just > > ignoring the hint. > > OK, I'll try to create a thread for the free page optimization. We create > the thread to poll for free pages at the beginning of the bulk stage, and > stops at the end of bulk stage. > There are also comments about postcopy support with this feature, I plan to > leave that as the second step (that support seems not urgent for now). > > > Best, > Wei you can make use the current migration thread instead of creating a new one. Liang