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 0D04A7F0C for ; Wed, 18 Apr 2018 17:10:52 +0200 (CEST) Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 719CE81A88C9; Wed, 18 Apr 2018 15:10:52 +0000 (UTC) Received: from [10.36.112.14] (unknown [10.36.112.14]) by smtp.corp.redhat.com (Postfix) with ESMTPS id DC67710F1BE8; Wed, 18 Apr 2018 15:10:51 +0000 (UTC) To: bluca@debian.org, stable@dpdk.org References: <20180418072408.18143-1-maxime.coquelin@redhat.com> From: Maxime Coquelin Message-ID: <397a2dee-db89-318a-6b51-be0f01be4e34@redhat.com> Date: Wed, 18 Apr 2018 17:10:49 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.7.0 MIME-Version: 1.0 In-Reply-To: <20180418072408.18143-1-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 2.78 on 10.11.54.3 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.8]); Wed, 18 Apr 2018 15:10:52 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.8]); Wed, 18 Apr 2018 15:10:52 +0000 (UTC) for IP:'10.11.54.3' DOMAIN:'int-mx03.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'maxime.coquelin@redhat.com' RCPT:'' Subject: Re: [dpdk-stable] [PATCH v16.11 LTS] vhost: avoid concurrency when logging dirty pages X-BeenThere: stable@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches for DPDK stable branches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 18 Apr 2018 15:10:53 -0000 On 04/18/2018 09:24 AM, Maxime Coquelin wrote: > [ backported from upstream commit 394313fff39d0f994325c47f7eab39daf5dc9e11 ] > > 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: 6bf02ab821fb ("vhost: make page logging atomic") > > Cc: stable@dpdk.org > > Signed-off-by: Maxime Coquelin > Reviewed-by: Jianfeng Tan > > Conflicts: > lib/librte_vhost/vhost.h > --- > > Hi Luca, > > This patch is backported from upstream master, > I propose it as the backport requires some conflicts to be fixed. > > Cheers, > Maxime > Hi Luca, Please don't apply the patch, I have just been made aware by QE that migration with more than one queue pair never converges, so I need to rework it. Cheers, Maxime