From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by dpdk.org (Postfix) with ESMTP id 3107F2C12; Fri, 30 Mar 2018 09:42:45 +0200 (CEST) Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 74595406E97C; Fri, 30 Mar 2018 07:42:44 +0000 (UTC) Received: from [10.36.112.32] (ovpn-112-32.ams2.redhat.com [10.36.112.32]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 653191C710; Fri, 30 Mar 2018 07:42:40 +0000 (UTC) To: dev@dpdk.org, jianfeng.tan@intel.com, tiwei.bie@intel.com, jfreimann@redhat.com Cc: stable@dpdk.org References: <20180321154413.1120-1-maxime.coquelin@redhat.com> From: Maxime Coquelin Message-ID: Date: Fri, 30 Mar 2018 09:42:39 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: <20180321154413.1120-1-maxime.coquelin@redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.11.54.5 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.7]); Fri, 30 Mar 2018 07:42:44 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.7]); Fri, 30 Mar 2018 07:42:44 +0000 (UTC) for IP:'10.11.54.5' DOMAIN:'int-mx05.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'maxime.coquelin@redhat.com' RCPT:'' Subject: Re: [dpdk-dev] [PATCH] vhost: avoid concurrency when logging dirty pages X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 30 Mar 2018 07:42:45 -0000 On 03/21/2018 04:44 PM, Maxime Coquelin wrote: > This patch aims at fixing a migration performance regression > faced since atomic operation is used to log pages as dirty when > doing live migration. > > Instead of setting a single bit by doing an atomic read-modify-write > operation to log a page as dirty, this patch write 0xFF to the > corresponding byte, and so logs 8 page as dirty. > > The advantage is that it avoids concurrent atomic operations by > multiple PMD threads, the drawback is that some clean pages are > marked as dirty and so are transferred twice. > > Fixes: 897f13a1f726 ("vhost: make page logging atomic") > Cc: stable@dpdk.org > > Signed-off-by: Maxime Coquelin > --- > lib/librte_vhost/vhost.h | 12 ++++-------- > 1 file changed, 4 insertions(+), 8 deletions(-) Applied to dpdk-next-virtio/master.