From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from out2-smtp.messagingengine.com (out2-smtp.messagingengine.com [66.111.4.26]) by dpdk.org (Postfix) with ESMTP id AC206A3 for ; Sat, 9 Mar 2019 00:19:49 +0100 (CET) Received: from compute1.internal (compute1.nyi.internal [10.202.2.41]) by mailout.nyi.internal (Postfix) with ESMTP id 492662204E; Fri, 8 Mar 2019 18:19:49 -0500 (EST) Received: from mailfrontend2 ([10.202.2.163]) by compute1.internal (MEProxy); Fri, 08 Mar 2019 18:19:49 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=monjalon.net; h= from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding:content-type; s=mesmtp; bh=Vfq4DNADHCl2QI22zfsi2AQGvfIIsl9cgsO0vSnv9yQ=; b=rKoexqLyvdyv ww3X0HQpQA9YC1Qo3Jdkvu3rd2XO6Nl9HTNxN0qUqBrI3e6EvZbCQjiNFoScRl59 pp/NoAdoFrCecKS6Ynl7hrZThm+O5znHuHyQNZb+KLdSvPdtcMHeYxan7BR10hiD 8najHJHB/ABb6d6T2/z405VVF4+2hZM= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-transfer-encoding:content-type :date:from:in-reply-to:message-id:mime-version:references :subject:to:x-me-proxy:x-me-proxy:x-me-sender:x-me-sender :x-sasl-enc; s=fm2; bh=Vfq4DNADHCl2QI22zfsi2AQGvfIIsl9cgsO0vSnv9 yQ=; b=i/5FpDVMtS0QzA1mLEZ2/tDZk516Di0G9Ujhb6nSByPZMvEy4Cz1ikByV I5V3isNNc8HRRbx3/ynzieg0MhxCgu6oXs6DX0ZdmWnYhb8zQDd2CPFXM5aXVjoL eHQ1Wo1BZXdINkmu0PLD58u0bIOEMiJjDXbJCILvv2DsuprCHjGCeewkP8nh2so4 ykUNY5FT3yY5h2uikvTW+GoWqlYExt+pt3vczWNxD9drb2OqoCEPYFasfk8/jugX J/i1naj0MHBde6KLXpzXzoe0QA8+Wo5FrBQC6uFGpVpGe2G/U65pGgokpV7TybSl I7EkmnVufA2e8R/B0JYn/umWivP4Q== X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedutddrgedugddtkecutefuodetggdotefrodftvf curfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfghnecu uegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenuc fjughrpefhvffufffkjghfggfgtgesthfuredttddtvdenucfhrhhomhepvfhhohhmrghs ucfoohhnjhgrlhhonhcuoehthhhomhgrshesmhhonhhjrghlohhnrdhnvghtqeenucfkph epjeejrddufeegrddvtdefrddukeegnecurfgrrhgrmhepmhgrihhlfhhrohhmpehthhho mhgrshesmhhonhhjrghlohhnrdhnvghtnecuvehluhhsthgvrhfuihiivgeptd X-ME-Proxy: Received: from xps.localnet (184.203.134.77.rev.sfr.net [77.134.203.184]) by mail.messagingengine.com (Postfix) with ESMTPA id 83C9210310; Fri, 8 Mar 2019 18:19:43 -0500 (EST) From: Thomas Monjalon To: "Ananyev, Konstantin" , "Gavin Hu (Arm Technology China)" Cc: Ilya Maximets , "dev@dpdk.org" , nd , "jerinj@marvell.com" , "hemant.agrawal@nxp.com" , "Nipun.gupta@nxp.com" , Honnappa Nagarahalli , "olivier.matz@6wind.com" , "Richardson, Bruce" , "chaozhu@linux.vnet.ibm.com" Date: Sat, 09 Mar 2019 00:18:08 +0100 Message-ID: <2456717.RLOWIjrx09@xps> In-Reply-To: <2601191342CEEE43887BDE71AB9772580136556F40@irsmsx105.ger.corp.intel.com> References: <1551841661-42892-1-git-send-email-gavin.hu@arm.com> <2601191342CEEE43887BDE71AB9772580136556F40@irsmsx105.ger.corp.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Subject: Re: [dpdk-dev] [PATCH v2] ring: enforce reading the tails before ring operations 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: Fri, 08 Mar 2019 23:19:50 -0000 08/03/2019 16:50, Ananyev, Konstantin: > 08/03/2019 16:05, Gavin Hu (Arm Technology China): > > Anyway, on x86, smp_rmb, as a compiler barrier, applies to load/store, not only load/load. > > Yes, that's true, but I think that's happened by coincidence, > not intentionally. > > > This is the case also for arm, arm64, ppc32, ppc64. > > I will submit a patch to expand the definition of this API. > > I understand your intention, but that does mean we would also need > to change not only rte_smp_rmb() but rte_rmb() too (to keep things consistent)? > That sounds worring. > Might be better to keep smp_rmb() definition as it is, and introduce new function > that fits your purposes (smp_rwmb or smp_load_store_barrier)? How is it managed in other projects?