From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from out4-smtp.messagingengine.com (out4-smtp.messagingengine.com [66.111.4.28]) by dpdk.org (Postfix) with ESMTP id A5ABA9E3 for ; Fri, 28 Apr 2017 11:14:26 +0200 (CEST) Received: from compute1.internal (compute1.nyi.internal [10.202.2.41]) by mailout.nyi.internal (Postfix) with ESMTP id 51D2520777; Fri, 28 Apr 2017 05:14:26 -0400 (EDT) Received: from frontend2 ([10.202.2.161]) by compute1.internal (MEProxy); Fri, 28 Apr 2017 05:14:26 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=monjalon.net; h= cc:content-transfer-encoding:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to:x-me-sender :x-me-sender:x-sasl-enc:x-sasl-enc; s=mesmtp; bh=2YPFes/duuTlguE Z7j5S4G1oAzrWW9XyVa3jL/AzlSw=; b=WOSrHPECt5jzAOQF6mu6vWYBcBaYbCY 3huBklUTVT9TleAu/Ixqyyml5NP0SIEHIZnOEn9usRLs3NcKls550nYHBMUYaP+v mrBMZIbnPITZiXSAvjHddVSdGqawIuSS/2VGAvW4yaC26IIizyFnMDarFJvo3biK C3kryI3FddAk= 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-sender:x-me-sender:x-sasl-enc:x-sasl-enc; s= fm1; bh=2YPFes/duuTlguEZ7j5S4G1oAzrWW9XyVa3jL/AzlSw=; b=JqHQ1iix T6+WkwXAc5ckYHc/k9MXetNTTj4CI8dYqyModftZCYK50mpE5ngphGRpYxLJYbDz pu/Csduh0N8zmwnKYuQ1j+DS8b2/eokHNSJyjfFpVyg6BlFficiObeKbS/K+/WWK Yhy5gSWDtgQ1/loVt/otkJ6aeRgvaD5gnkUL24gb8Xjj0446djwohAMfgq3nfejs hwXDT7C0YMf4X73LwwJ6yN8qKnKSS71tfFaMDntOz4Gz6WNWTK0UI0LSeoT7cgO8 4Sf3VD5VPHv3Fl2jNOnt6wiG2SOP09q7kG6WBxdl+ol7rC/7oZH0SHz7AL5jWrAw 0W76UB9x15HrSw== X-ME-Sender: X-Sasl-enc: rMf5kiQOlLn10zuTyBsx86Naht2lzMsPeVcMgMysDqsd 1493370865 Received: from xps.localnet (184.203.134.77.rev.sfr.net [77.134.203.184]) by mail.messagingengine.com (Postfix) with ESMTPA id AD2DA2415E; Fri, 28 Apr 2017 05:14:25 -0400 (EDT) From: Thomas Monjalon To: Qi Zhang Cc: dev@dpdk.org, Bruce Richardson , jingjing.wu@intel.com, helin.zhang@intel.com, wenzhuo.lu@intel.com, jing.d.chen@intel.com, ferruh.yigit@intel.com Date: Fri, 28 Apr 2017 11:14:24 +0200 Message-ID: <1655942.nOeDIEQQQZ@xps> In-Reply-To: <20170427092539.GA7544@bricha3-MOBL3.ger.corp.intel.com> References: <20170424145848.18544-1-qi.z.zhang@intel.com> <20170427070107.65465-1-qi.z.zhang@intel.com> <20170427092539.GA7544@bricha3-MOBL3.ger.corp.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Subject: Re: [dpdk-dev] [PATCH 0/3 v2] disable vector PMD for i686 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, 28 Apr 2017 09:14:26 -0000 27/04/2017 11:25, Bruce Richardson: > On Thu, Apr 27, 2017 at 03:01:04AM -0400, Qi Zhang wrote: > > Vector PMD is not designed for i686 orginally, but it still can be active > > with i686 compile option. > > Below are observed failure when vPMD is invovled on i686 > > (but may not limited to) > > > > 1) memory overwrite when assign 2 mbuf points to rx return points. > > _mm_storeu_si128((__m128i *)&rx_pkts[pos+2], mbp2) > > Is this a serious issue that prevents us using the driver? I think it's been > in the code for quite some time. Can it not be relatively easily fixed for > 32-bit builds? > > > > > 2) rearm_data is not 16 bytes aligned that cause general-protection exception > > _mm_store_si128((__m128i *)&rx_pkts[0]->rearm_data, rearm0); > > > > Good catch. I think this is also an easy fix. My preferred fix is to > explicitly align the rearm data on a 16-byte boundary. It would add some > padding to the middle of cacheline0 of the mbuf, but given that we > explicitly move other data to cacheline1, we will have padding on 32-bit > anyway, be it in the middle or the end of the mbuf cachelines. > > > So the patch set will exclude Vector PMD from compile with i686 configure. Please try to fix the drivers instead of turning them off.