Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754531AbcJUGhC (ORCPT ); Fri, 21 Oct 2016 02:37:02 -0400 Received: from mga02.intel.com ([134.134.136.20]:49759 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750856AbcJUGhA (ORCPT ); Fri, 21 Oct 2016 02:37:00 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.31,375,1473145200"; d="scan'208";a="1057003274" From: Liang Li To: mst@redhat.com Cc: linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, linux-mm@kvack.org, virtio-dev@lists.oasis-open.org, kvm@vger.kernel.org, qemu-devel@nongnu.org, quintela@redhat.com, dgilbert@redhat.com, dave.hansen@intel.com, pbonzini@redhat.com, cornelia.huck@de.ibm.com, amit.shah@redhat.com, Liang Li Subject: [RESEND PATCH v3 kernel 0/7] Extend virtio-balloon for fast (de)inflating & fast live migration Date: Fri, 21 Oct 2016 14:24:33 +0800 Message-Id: <1477031080-12616-1-git-send-email-liang.z.li@intel.com> X-Mailer: git-send-email 1.9.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2216 Lines: 49 This patch set contains two parts of changes to the virtio-balloon. One is the change for speeding up the inflating & deflating process, the main idea of this optimization is to use bitmap to send the page information to host instead of the PFNs, to reduce the overhead of virtio data transmission, address translation and madvise(). This can help to improve the performance by about 85%. Another change is for speeding up live migration. By skipping process guest's free pages in the first round of data copy, to reduce needless data processing, this can help to save quite a lot of CPU cycles and network bandwidth. We put guest's free page information in bitmap and send it to host with the virt queue of virtio-balloon. For an idle 8GB guest, this can help to shorten the total live migration time from 2Sec to about 500ms in the 10Gbps network environment. Dave Hansen suggested a new scheme to encode the data structure, because of additional complexity, it's not implemented in v3. Changes from v2 to v3: * Change the name of 'free page' to 'unused page'. * Use the scatter & gather bitmap instead of a 1MB page bitmap. * Fix overwriting the page bitmap after kicking. * Some of MST's comments for v2. Changes from v1 to v2: * Abandon the patch for dropping page cache. * Put some structures to uapi head file. * Use a new way to determine the page bitmap size. * Use a unified way to send the free page information with the bitmap * Address the issues referred in MST's comments Liang Li (7): virtio-balloon: rework deflate to add page to a list virtio-balloon: define new feature bit and page bitmap head mm: add a function to get the max pfn virtio-balloon: speed up inflate/deflate process mm: add the related functions to get unused page virtio-balloon: define feature bit and head for misc virt queue virtio-balloon: tell host vm's unused page info drivers/virtio/virtio_balloon.c | 390 ++++++++++++++++++++++++++++++++---- include/linux/mm.h | 3 + include/uapi/linux/virtio_balloon.h | 41 ++++ mm/page_alloc.c | 94 +++++++++ 4 files changed, 485 insertions(+), 43 deletions(-) -- 1.8.3.1