From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by dpdk.org (Postfix) with ESMTP id 7D5F51BE0D; Thu, 20 Dec 2018 19:19:56 +0100 (CET) Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id D427E2DC342; Thu, 20 Dec 2018 18:19:55 +0000 (UTC) Received: from [10.36.112.60] (ovpn-112-60.ams2.redhat.com [10.36.112.60]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 1C67017D81; Thu, 20 Dec 2018 18:19:50 +0000 (UTC) To: dev@dpdk.org, i.maximets@samsung.com, tiwei.bie@intel.com, zhihong.wang@intel.com, jasowang@redhat.com, mst@redhat.com Cc: stable@dpdk.org References: <20181219082113.24455-1-maxime.coquelin@redhat.com> From: Maxime Coquelin Message-ID: <8df01d5a-af91-0dd0-a804-31480ad810c9@redhat.com> Date: Thu, 20 Dec 2018 19:19:49 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.3.1 MIME-Version: 1.0 In-Reply-To: <20181219082113.24455-1-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 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.29]); Thu, 20 Dec 2018 18:19:55 +0000 (UTC) Subject: Re: [dpdk-dev] [PATCH v2 0/4] vhost: add missing barriers, move prefetching 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: Thu, 20 Dec 2018 18:19:56 -0000 On 12/19/18 9:21 AM, Maxime Coquelin wrote: > This series adds missing read barriers after reading avail index > for split ring and desc flags for packed ring. > > Also, it turns out that some descriptors prefetching are either > badly placed, or useless, last part of the series fixes that. > > With the series applied, I get between 0 and 4% gain depending > on the benchmark (testpmd txonly/rxonly/io). > > Thanks to Jason for reporting the missing read barriers. > > Changes since v1: > ================= > - Drop volatile removal patch (Ilya) > - Improve commit messages for RMB patches (Ilya) > > Maxime Coquelin (4): > vhost: enforce avail index and desc read ordering > vhost: enforce desc flags and content read ordering > vhost: prefetch descriptor after the read barrier > vhost: remove useless prefetch for packed ring descriptor > > lib/librte_vhost/virtio_net.c | 27 ++++++++++++++++++++++----- > 1 file changed, 22 insertions(+), 5 deletions(-) > Applied to dpdk-next-virtio. Maxime