From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dpdk.org (dpdk.org [92.243.14.124]) by dpdk.space (Postfix) with ESMTP id 72A06A05D3 for ; Mon, 25 Mar 2019 09:26:19 +0100 (CET) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id 9D7E32BF7; Mon, 25 Mar 2019 09:26:17 +0100 (CET) Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by dpdk.org (Postfix) with ESMTP id 3C6412BD3 for ; Mon, 25 Mar 2019 09:26:16 +0100 (CET) Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 879AE3083363; Mon, 25 Mar 2019 08:26:15 +0000 (UTC) Received: from [10.36.112.59] (ovpn-112-59.ams2.redhat.com [10.36.112.59]) by smtp.corp.redhat.com (Postfix) with ESMTPS id D112A60BF7; Mon, 25 Mar 2019 08:26:14 +0000 (UTC) To: "Lu, Wenzhuo" , "dev@dpdk.org" References: <1551340136-83843-1-git-send-email-wenzhuo.lu@intel.com> <1553223516-118453-1-git-send-email-wenzhuo.lu@intel.com> <1553223516-118453-7-git-send-email-wenzhuo.lu@intel.com> <6A0DE07E22DDAD4C9103DF62FEBC0909407EFDD1@shsmsx102.ccr.corp.intel.com> From: Maxime Coquelin Message-ID: Date: Mon, 25 Mar 2019 09:26:11 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.5.1 MIME-Version: 1.0 In-Reply-To: <6A0DE07E22DDAD4C9103DF62FEBC0909407EFDD1@shsmsx102.ccr.corp.intel.com> Content-Type: text/plain; charset="UTF-8"; format="flowed" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.44]); Mon, 25 Mar 2019 08:26:15 +0000 (UTC) Subject: Re: [dpdk-dev] [PATCH v5 6/8] net/ice: support Rx AVX2 vector 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: , Errors-To: dev-bounces@dpdk.org Sender: "dev" Message-ID: <20190325082611.cG_KZZxm1mjqqeZNiQx3mrjszIk63115SjXR0XMNuDA@z> Hi, On 3/25/19 3:22 AM, Lu, Wenzhuo wrote: > Hi Maxime, > > >> -----Original Message----- >> From: Maxime Coquelin [mailto:maxime.coquelin@redhat.com] >> Sent: Friday, March 22, 2019 6:12 PM >> To: Lu, Wenzhuo ; dev@dpdk.org >> Subject: Re: [dpdk-dev] [PATCH v5 6/8] net/ice: support Rx AVX2 vector > > >>> +#ifndef RTE_LIBRTE_ICE_16BYTE_RX_DESC >> >> I see same is done for other Intel NICs, but I wonder what would be the >> performance cost of making it dynamic, if any cost? > Currently we don't have a good idea to make it dynamic. If we use pointer to point to different functions for 16 byte and 32 byte, there's too much duplicate code to make it hard to maintain. If we use the same function, and check the configure in it. It impacts the performance. Have you done some measurements, what would be the performance impact? > As HW does not support to change the configuration dynamically. The device must be stopped and restarted if the configuration is changed. It's not very helpful to make it a dynamic configuration. We assume that the users can make their choice at the beginning and will not change it. The problem is that the user has to recompile to switch between the two configurations. And it may not be an option for the user if he uses dpdk packaged by a distribution, for example. Maybe I was not clear, but I don't mean to be able to switch mode while the port is started. I think it would be better to make it possible to switch mode at application startup time. > >> >> Having it dynamic (as a dev arg for instance) would make it possible to >> change the value when the user is using dpdk from a distro. It would also >> help testing coverage. >> >> Btw, how do you select this option with meson build system? > Not very familiar with meson. As I know, we can change the meson.build to add the configure. > Ok, then please try to do it, because the legacy build system is going to be deprecated.