From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.droids-corp.org (zoll.droids-corp.org [94.23.50.67]) by dpdk.org (Postfix) with ESMTP id B22E058F4 for ; Mon, 26 May 2014 16:19:50 +0200 (CEST) Received: from was59-1-82-226-113-214.fbx.proxad.net ([82.226.113.214] helo=[192.168.0.10]) by mail.droids-corp.org with esmtpsa (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:128) (Exim 4.80) (envelope-from ) id 1WovmU-0001fe-BG; Mon, 26 May 2014 16:21:50 +0200 Message-ID: <53834D95.30309@6wind.com> Date: Mon, 26 May 2014 16:20:05 +0200 From: Olivier MATZ User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Icedove/24.4.0 MIME-Version: 1.0 To: "Ananyev, Konstantin" , "dev@dpdk.org" References: <1400578588-21137-1-git-send-email-olivier.matz@6wind.com> <2601191342CEEE43887BDE71AB9772580EFA776F@IRSMSX105.ger.corp.intel.com> <537F56C3.3060503@6wind.com> <2601191342CEEE43887BDE71AB9772580EFB0A95@IRSMSX105.ger.corp.intel.com> In-Reply-To: <2601191342CEEE43887BDE71AB9772580EFB0A95@IRSMSX105.ger.corp.intel.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [dpdk-dev] [PATCH] atomic: clarify use of memory barriers 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: Mon, 26 May 2014 14:19:50 -0000 Hi Konstantin, On 05/26/2014 03:57 PM, Ananyev, Konstantin wrote: > In most cases just a compiler barrier is enough, but there are few exceptions. > Always using fence instructions - means introduce unnecessary slowdown for cases, when order is guaranteed. > No using fences in cases, when they are needed - means introduce race window and possible data corruption. > That's why right now people can use either rte_compiler_barrier() or mb/rmb/wmb - whatever is appropriate for particular case. OK, so let's drop this patch for now. Thank you for reviewing and commenting. Regards, Olivier