From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by dpdk.org (Postfix) with ESMTP id 826D529D2 for ; Thu, 25 Feb 2016 14:35:22 +0100 (CET) Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by orsmga101.jf.intel.com with ESMTP; 25 Feb 2016 05:35:21 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.22,498,1449561600"; d="scan'208";a="923717868" Received: from bricha3-mobl3.ger.corp.intel.com ([10.237.208.64]) by fmsmga002.fm.intel.com with SMTP; 25 Feb 2016 05:35:18 -0800 Received: by (sSMTP sendmail emulation); Thu, 25 Feb 2016 13:35:18 +0025 Date: Thu, 25 Feb 2016 13:35:18 +0000 From: Bruce Richardson To: "Chen, Jing D" Message-ID: <20160225133518.GB20868@bricha3-MOBL3> References: <1454410216-13333-2-git-send-email-xiao.w.wang@intel.com> <1454557129-12825-2-git-send-email-xiao.w.wang@intel.com> <20160224154255.GA21808@bricha3-MOBL3> <13026611.uCVrZtfrBT@xps13> <4341B239C0EFF9468EE453F9E9F4604D04450107@shsmsx102.ccr.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4341B239C0EFF9468EE453F9E9F4604D04450107@shsmsx102.ccr.corp.intel.com> Organization: Intel Shannon Ltd. User-Agent: Mutt/1.5.23 (2014-03-12) Cc: "dev@dpdk.org" Subject: Re: [dpdk-dev] [PATCH v3 1/3] fm10k: enable FTAG based forwarding 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: Thu, 25 Feb 2016 13:35:23 -0000 On Thu, Feb 25, 2016 at 10:04:02AM +0000, Chen, Jing D wrote: > Hi, Bruce, Thomas, > > Best Regards, > Mark > > > -----Original Message----- > > From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Thomas Monjalon > > Sent: Thursday, February 25, 2016 12:38 AM > > To: Richardson, Bruce; Wang, Xiao W > > Cc: dev@dpdk.org > > Subject: Re: [dpdk-dev] [PATCH v3 1/3] fm10k: enable FTAG based > > forwarding > > > > 2016-02-24 15:42, Bruce Richardson: > > > On Thu, Feb 04, 2016 at 11:38:47AM +0800, Wang Xiao W wrote: > > > > This patch enables reading sglort info into mbuf for RX and inserting > > > > an FTAG at the beginning of the packet for TX. The vlan_tci_outer field > > > > selected from rte_mbuf structure for sglort is not used in fm10k now. > > > > In FTAG based forwarding mode, the switch will forward packets > > according > > > > to glort info in FTAG rather than mac and vlan table. > > > > > > > > To activate this feature, user needs to turn > > ``CONFIG_RTE_LIBRTE_FM10K_FTAG_FWD`` > > > > to y in common_linuxapp or common_bsdapp. Currently this feature is > > supported > > > > only on PF, because FM10K_PFVTCTL register is read-only for VF. > > > > > > > > Signed-off-by: Wang Xiao W > > > > > > Any comments on this patch? > > > > > > My thoughts: is there a way in which this could be done without adding in a > > new > > > build time config option? > > > > Bruce, it's simpler to explain that build time options are forbidden to > > enable such options. > > Or the terrific kid's approach: one day, the Big Build-Option Eater will come > > and will eat every undecided features! ;) > > This feature is trying to use FTAG (a unique tech in fm10k) instead of mac/vlan > to forward packets. App need a way to tell PMD driver that which forwarding > style it would like to use. Why not just specify this in the port configuration at setup time? > So, the best option is to let packets carry a flag in mbuf to tell drive in fast path. > You can see that this is unique to fm10k and we thought community won't like to see > this flag introduced into mbuf. If you do agree, we can introduce a new flag. Why does it need to be specified per-mbuf? The existing config flag added is global, so a per-mbuf flag shouldn't be needed to get equivalent behaviour. > So, we step backwards and assume customer will use static configurations to enable > this feature. After it is enabled, we'll assume app will use FTAG for all packets. Yes, but instead of compile time option, why not port config-time option instead? /Bruce