From mboxrd@z Thu Jan 1 00:00:00 1970 From: Amit Shah Subject: Re: [RFC Design Doc]Speed up live migration by skipping free pages Date: Fri, 1 Apr 2016 16:24:50 +0530 Message-ID: <20160401105450.GB21483@grmbl.mre> References: <1458632629-4649-1-git-send-email-liang.z.li@intel.com> <20160322190530.GI2216@work-vm> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: rkagan@virtuozzo.com, linux-kernel@vger.kenel.org, ehabkost@redhat.com, kvm@vger.kernel.org, mst@redhat.com, simhan@hpe.com, Liang Li , qemu-devel@nongnu.org, jitendra.kolhe@hpe.com, quintela@redhat.com, mohan_parthasarathy@hpe.com, pbonzini@redhat.com, rth@twiddle.net To: "Dr. David Alan Gilbert" Return-path: Content-Disposition: inline In-Reply-To: <20160322190530.GI2216@work-vm> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+gceq-qemu-devel=gmane.org@nongnu.org Sender: qemu-devel-bounces+gceq-qemu-devel=gmane.org@nongnu.org List-Id: kvm.vger.kernel.org On (Tue) 22 Mar 2016 [19:05:31], Dr. David Alan Gilbert wrote: > * Liang Li (liang.z.li@intel.com) wrote: > > b. Implement a new virtio device > > Implementing a brand new virtio device to exchange information > > between host and guest is another choice. It requires modifying the > > virtio spec too. > > If the right solution is to change the spec then we should do it; > we shouldn't use a technically worse solution just to avoid the spec > change; although we have to be even more careful to get the right > solution if we want to change the spec. Yes, absolutely. I didn't mean to suggest virtio-serial because it'll help us save with modifying specs. I suggested it because for me, the most important point was that if a guest is sensitive to latencies or spikes, the balloon driver is definitely going to be not installed by the guest admin. (I'm still not caught up on this thread, but wanted to clarify this right away.) Amit From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57109) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1alwjJ-0006ch-0Z for qemu-devel@nongnu.org; Fri, 01 Apr 2016 06:55:05 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1alwjF-0004Yq-0v for qemu-devel@nongnu.org; Fri, 01 Apr 2016 06:55:04 -0400 Received: from mx1.redhat.com ([209.132.183.28]:52028) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1alwjE-0004Yl-Rs for qemu-devel@nongnu.org; Fri, 01 Apr 2016 06:55:00 -0400 Date: Fri, 1 Apr 2016 16:24:50 +0530 From: Amit Shah Message-ID: <20160401105450.GB21483@grmbl.mre> References: <1458632629-4649-1-git-send-email-liang.z.li@intel.com> <20160322190530.GI2216@work-vm> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160322190530.GI2216@work-vm> Subject: Re: [Qemu-devel] [RFC Design Doc]Speed up live migration by skipping free pages List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Dr. David Alan Gilbert" Cc: rkagan@virtuozzo.com, linux-kernel@vger.kenel.org, ehabkost@redhat.com, kvm@vger.kernel.org, mst@redhat.com, simhan@hpe.com, Liang Li , qemu-devel@nongnu.org, jitendra.kolhe@hpe.com, quintela@redhat.com, mohan_parthasarathy@hpe.com, pbonzini@redhat.com, rth@twiddle.net On (Tue) 22 Mar 2016 [19:05:31], Dr. David Alan Gilbert wrote: > * Liang Li (liang.z.li@intel.com) wrote: > > b. Implement a new virtio device > > Implementing a brand new virtio device to exchange information > > between host and guest is another choice. It requires modifying the > > virtio spec too. > > If the right solution is to change the spec then we should do it; > we shouldn't use a technically worse solution just to avoid the spec > change; although we have to be even more careful to get the right > solution if we want to change the spec. Yes, absolutely. I didn't mean to suggest virtio-serial because it'll help us save with modifying specs. I suggested it because for me, the most important point was that if a guest is sensitive to latencies or spikes, the balloon driver is definitely going to be not installed by the guest admin. (I'm still not caught up on this thread, but wanted to clarify this right away.) Amit