From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pl0-f72.google.com (mail-pl0-f72.google.com [209.85.160.72]) by kanga.kvack.org (Postfix) with ESMTP id 0BF506B0003 for ; Sun, 22 Jul 2018 07:12:05 -0400 (EDT) Received: by mail-pl0-f72.google.com with SMTP id 66-v6so11053253plb.18 for ; Sun, 22 Jul 2018 04:12:05 -0700 (PDT) Received: from mga07.intel.com (mga07.intel.com. [134.134.136.100]) by mx.google.com with ESMTPS id d31-v6si5760819pla.190.2018.07.22.04.12.03 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 22 Jul 2018 04:12:03 -0700 (PDT) From: "Wang, Wei W" Subject: RE: [PATCH v36 0/5] Virtio-balloon: support free page reporting Date: Sun, 22 Jul 2018 11:11:59 +0000 Message-ID: <286AC319A985734F985F78AFA26841F739702695@SHSMSX101.ccr.corp.intel.com> References: <1532075585-39067-1-git-send-email-wei.w.wang@intel.com> <20180720154922-mutt-send-email-mst@kernel.org> In-Reply-To: <20180720154922-mutt-send-email-mst@kernel.org> Content-Language: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Sender: owner-linux-mm@kvack.org List-ID: To: "Michael S. Tsirkin" 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" , "torvalds@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" , "peterx@redhat.com" On Friday, July 20, 2018 8:52 PM, Michael S. Tsirkin wrote: > On Fri, Jul 20, 2018 at 04:33:00PM +0800, Wei Wang wrote: > > This patch series is separated from the previous "Virtio-balloon > > Enhancement" series. The new feature, > VIRTIO_BALLOON_F_FREE_PAGE_HINT, > > implemented by this series enables the virtio-balloon driver to report > > hints of guest free pages to the host. It can be used to accelerate > > live migration of VMs. Here is an introduction of this usage: > > > > Live migration needs to transfer the VM's memory from the source > > machine to the destination round by round. For the 1st round, all the > > VM's memory is transferred. From the 2nd round, only the pieces of > > memory that were written by the guest (after the 1st round) are > > transferred. One method that is popularly used by the hypervisor to > > track which part of memory is written is to write-protect all the guest > memory. > > > > This feature enables the optimization by skipping the transfer of > > guest free pages during VM live migration. It is not concerned that > > the memory pages are used after they are given to the hypervisor as a > > hint of the free pages, because they will be tracked by the hypervisor > > and transferred in the subsequent round if they are used and written. > > > > * Tests > > - Test Environment > > Host: Intel(R) Xeon(R) CPU E5-2699 v4 @ 2.20GHz > > Guest: 8G RAM, 4 vCPU > > Migration setup: migrate_set_speed 100G, migrate_set_downtime 2 > > second >=20 > Can we split out patches 1 and 2? They seem appropriate for this release = ... Sounds good to me. I'm not sure if there would be comments on the first 2 p= atches. If no, can you just take them here? Or you need me to repost them s= eparately? Best, Wei