From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by dpdk.org (Postfix) with ESMTP id 1F3925590 for ; Fri, 18 Mar 2016 10:45:21 +0100 (CET) Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga101.jf.intel.com with ESMTP; 18 Mar 2016 02:45:21 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.24,354,1455004800"; d="scan'208";a="936681093" Received: from yliu-dev.sh.intel.com (HELO yliu-dev) ([10.239.66.49]) by orsmga002.jf.intel.com with ESMTP; 18 Mar 2016 02:45:20 -0700 Date: Fri, 18 Mar 2016 17:46:42 +0800 From: Yuanhan Liu To: Thomas Monjalon Cc: dev@dpdk.org, Ilya Maximets , Huawei Xie , bruce.richardson@intel.com, Dyasly Sergey , Jerin Jacob , Jianbo Liu , Tetsuya Mukawa Message-ID: <20160318094642.GA23215@yliu-dev.sh.intel.com> References: <1456314438-4021-1-git-send-email-i.maximets@samsung.com> <9470086.ZYvecjaNVJ@xps13> <20160318091614.GT979@yliu-dev.sh.intel.com> <3519170.fnd0yd7nVF@xps13> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3519170.fnd0yd7nVF@xps13> User-Agent: Mutt/1.5.23 (2014-03-12) Subject: Re: [dpdk-dev] [PATCH RFC v3 0/3] Thread safe rte_vhost_enqueue_burst(). X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 18 Mar 2016 09:45:22 -0000 On Fri, Mar 18, 2016 at 10:34:56AM +0100, Thomas Monjalon wrote: > 2016-03-18 17:16, Yuanhan Liu: > > On Fri, Mar 18, 2016 at 09:09:04AM +0100, Thomas Monjalon wrote: > > > 2016-03-18 16:00, Yuanhan Liu: > > > > On Thu, Mar 17, 2016 at 04:29:32PM +0100, Thomas Monjalon wrote: > > > > > 2016-02-24 14:47, Ilya Maximets: > > > > > > Implementation of rte_vhost_enqueue_burst() based on lockless ring-buffer > > > > > > algorithm and contains almost all to be thread-safe, but it's not. > > > > > > > > > > > > This set adds required changes. > > > > > > > > > > > > First patch in set is a standalone patch that fixes many times discussed > > > > > > issue with barriers on different architectures. > > > > > > > > > > > > Second and third adds fixes to make rte_vhost_enqueue_burst thread safe. > > > > > > > > > > My understanding is that we do not want to pollute Rx/Tx with locks. > > > > > > > > > > Huawei, Yuanhan, Bruce, do you confirm? > > > > > > > > Huawei would like to do that, and I'm behind that. Let's do it. > > > > > > I'm not sure to understand. What do you want to do exactly? > > > > I was thinking we are on the same page :( > > Yes we are on the same page. > But it's better to make things explicit. > > There should be no lock in Rx/Tx drivers (including vhost). > The locking must be done by the caller (application level). Yeah, that's why Huawei made the proposal and the patch. > That's why this series "Thread safe rte_vhost_enqueue_burst" is rejected. > > > "do not want to pollute Rx/Tx with locks" == "remove lockless Rx/Tx, the > > proposal from Huawei", right? > > > > In another way, I'm behind the following patch from Huawei: > > > > http://dpdk.org/dev/patchwork/patch/9740/ > > The patch "vhost: remove lockless enqueue to the virtio ring" must me > reworked in 2 patches: > 1/ announce API change That was my concern, and agreed we need that. > 2/ remove locks > > Please avoid talking about removing "lockless" when actually removing locks. Sorry, my bad. --yliu