From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) by dpdk.org (Postfix) with ESMTP id 89F3C324D; Thu, 20 Dec 2018 05:41:16 +0100 (CET) X-Amp-Result: UNSCANNABLE X-Amp-File-Uploaded: False Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by orsmga103.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 19 Dec 2018 20:41:15 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.56,375,1539673200"; d="scan'208";a="303673490" Received: from dpdk-tbie.sh.intel.com ([10.67.104.173]) by fmsmga006.fm.intel.com with ESMTP; 19 Dec 2018 20:41:13 -0800 Date: Thu, 20 Dec 2018 12:39:10 +0800 From: Tiwei Bie To: Maxime Coquelin Cc: dev@dpdk.org, i.maximets@samsung.com, zhihong.wang@intel.com, jasowang@redhat.com, mst@redhat.com, stable@dpdk.org Message-ID: <20181220043910.GA21484@dpdk-tbie.sh.intel.com> References: <20181219082113.24455-1-maxime.coquelin@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20181219082113.24455-1-maxime.coquelin@redhat.com> User-Agent: Mutt/1.9.4 (2018-02-28) 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 04:41:17 -0000 On Wed, Dec 19, 2018 at 09:21:09AM +0100, 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(-) Acked-by: Tiwei Bie