From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by dpdk.org (Postfix) with ESMTP id A9AE82C12 for ; Thu, 1 Mar 2018 14:18:07 +0100 (CET) Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 99E314026768; Thu, 1 Mar 2018 13:18:06 +0000 (UTC) Received: from [10.72.12.22] (ovpn-12-22.pek2.redhat.com [10.72.12.22]) by smtp.corp.redhat.com (Postfix) with ESMTPS id D25232026E04; Thu, 1 Mar 2018 13:18:04 +0000 (UTC) To: "Zhang, Qi Z" Cc: "Karlsson, Magnus" , "Topel, Bjorn" , "dev@dpdk.org" References: <20180227093306.23854-1-qi.z.zhang@intel.com> <4758d934-c338-e4a6-17fa-6ed90bb141ff@redhat.com> <039ED4275CED7440929022BC67E706115315D465@SHSMSX103.ccr.corp.intel.com> <039ED4275CED7440929022BC67E706115315D47B@SHSMSX103.ccr.corp.intel.com> <039ED4275CED7440929022BC67E706115315D771@SHSMSX103.ccr.corp.intel.com> From: Jason Wang Message-ID: <23b8bd50-cf2a-fce1-dc0a-20a52d33cf77@redhat.com> Date: Thu, 1 Mar 2018 21:18:01 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: <039ED4275CED7440929022BC67E706115315D771@SHSMSX103.ccr.corp.intel.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US X-Scanned-By: MIMEDefang 2.78 on 10.11.54.4 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.6]); Thu, 01 Mar 2018 13:18:06 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.6]); Thu, 01 Mar 2018 13:18:06 +0000 (UTC) for IP:'10.11.54.4' DOMAIN:'int-mx04.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'jasowang@redhat.com' RCPT:'' Subject: Re: [dpdk-dev] [RFC 0/7] PMD driver for AF_XDP 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: Thu, 01 Mar 2018 13:18:07 -0000 On 2018年03月01日 20:56, Zhang, Qi Z wrote: >>>>>> BTW, performance test shows our PMD can reach 94%~98% of the >>>>>> orignal benchmark when share memory is enabled. >>>>> Hi: >>>>> >>>>> Looks like zero copy is not used in this series. Any plan to support that? >>>> Zero copy is enabled in patch 5, if a mempool passed check_mempool, >>>> it will be registered to af_xdp socket. >>>> so there will be no memcpy between mbuf and af_xdp. >> Aha, I see. So the zerocopy was limited to some specific use case. And if I >> understand it correctly, zc mode could not be used for VM. > I think except the limitation for mempool layout, zerocopy is transparent to DPDK application, only difference is performance. > Sorry, I may not get your point, if you could explain more about the VM usage. > > Regards > Qi No problem, so the question is: Can zerocopy be used when using testpmd to foward packets between vhost-user and AF_XDP socket? Thanks