From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by dpdk.org (Postfix) with ESMTP id 2DBEE2C72 for ; Wed, 19 Apr 2017 08:14:36 +0200 (CEST) Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga102.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 18 Apr 2017 23:14:35 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.37,219,1488873600"; d="scan'208";a="1121218774" Received: from yliu-dev.sh.intel.com (HELO yliu-dev) ([10.239.67.162]) by orsmga001.jf.intel.com with ESMTP; 18 Apr 2017 23:14:34 -0700 Date: Wed, 19 Apr 2017 14:11:27 +0800 From: Yuanhan Liu To: dev@dpdk.org Cc: Maxime Coquelin Message-ID: <20170419061127.GB31523@yliu-dev.sh.intel.com> References: <1492156398-14405-1-git-send-email-yuanhan.liu@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1492156398-14405-1-git-send-email-yuanhan.liu@linux.intel.com> User-Agent: Mutt/1.5.23 (2014-03-12) Subject: Re: [dpdk-dev] [PATCH] vhost: avoid memory write on net header when necessary 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: Wed, 19 Apr 2017 06:14:37 -0000 On Fri, Apr 14, 2017 at 03:53:18PM +0800, Yuanhan Liu wrote: > Like what we did for virtio PMD driver [0][1], we could also apply such > trick to vhost, to avoid the memory write on net header when necessary. > > [0]: c9ea670c1dc7 ("net/virtio: fix performance regression due to TSO") > [1]: 16994abee215 ("net/virtio: optimize header reset on any layout") > > With this, the cache issue of the mergeable path is again greatly reduced: > even the write of "num_buffers" could be avoided. A quick PVP test shows > the gap between the mergeable Rx and non-mergable Rx is pretty small now: > they are basically the same in my test. > > Signed-off-by: Yuanhan Liu Applied to dpdk-next-virtio. --yliu