From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:46916) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ejsbk-000820-LX for qemu-devel@nongnu.org; Thu, 08 Feb 2018 15:15:49 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ejsbh-0004mt-8r for qemu-devel@nongnu.org; Thu, 08 Feb 2018 15:15:48 -0500 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:53994 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ejsbh-0004gL-2n for qemu-devel@nongnu.org; Thu, 08 Feb 2018 15:15:45 -0500 Date: Thu, 8 Feb 2018 20:15:24 +0000 From: "Dr. David Alan Gilbert" Message-ID: <20180208201523.GE2326@work-vm> References: <1517915299-15349-1-git-send-email-wei.w.wang@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1517915299-15349-1-git-send-email-wei.w.wang@intel.com> Subject: Re: [Qemu-devel] [PATCH v2 0/3] virtio-balloon: free page hint reporting support List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Wei Wang Cc: qemu-devel@nongnu.org, virtio-dev@lists.oasis-open.org, mst@redhat.com, quintela@redhat.com, pbonzini@redhat.com, liliang.opensource@gmail.com, yang.zhang.wz@gmail.com, quan.xu0@gmail.com, nilal@redhat.com, riel@redhat.com * Wei Wang (wei.w.wang@intel.com) wrote: > This is the deivce part implementation to add a new feature, > VIRTIO_BALLOON_F_FREE_PAGE_HINT to the virtio-balloon device. The device > receives the guest free page hints from the driver and clears the > corresponding bits in the dirty bitmap, so that those free pages are > not transferred by the migration thread to the destination. > > Please see the driver patch link for test results: > https://lkml.org/lkml/2018/2/4/60 Hi Wei, I'll look at the code a bit more - but first some more basic questions on that lkml post: a) The idle guest time thing is a nice result; can you just state what the host was, speed of connection, and what other options you were using? b) The workload test, the one with the kernel compile; you list the kernel compile time but don't mention any changes in the migration times of the ping-pong; can you give those times as well? c) What's your real workload that this is aimed at? Is it really for people migrating idle VMs - or do you have some NFV application in mind, if so why not include a figure for those? Thanks, Dave > ChangeLog: > v1->v2: > 1) virtio-balloon > - use subsections to save free_page_report_cmd_id; > - poll the free page vq after sending a cmd id to the driver; > - change the free page vq size to VIRTQUEUE_MAX_SIZE; > - virtio_balloon_poll_free_page_hints: handle the corner case > that the free page block reported from the driver may cross > the RAMBlock boundary. > 2) migration/ram.c > - use balloon_free_page_poll to start the optimization > > Wei Wang (3): > virtio-balloon: VIRTIO_BALLOON_F_FREE_PAGE_HINT > migration: use the free page reporting feature from balloon > virtio-balloon: add a timer to limit the free page report waiting time > > balloon.c | 39 ++-- > hw/virtio/virtio-balloon.c | 227 ++++++++++++++++++++++-- > hw/virtio/virtio-pci.c | 3 + > include/hw/virtio/virtio-balloon.h | 15 +- > include/migration/misc.h | 3 + > include/standard-headers/linux/virtio_balloon.h | 7 + > include/sysemu/balloon.h | 12 +- > migration/ram.c | 34 +++- > 8 files changed, 307 insertions(+), 33 deletions(-) > > -- > 1.8.3.1 > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK