From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by dpdk.org (Postfix) with ESMTP id 36A3B5A2D for ; Tue, 26 May 2015 17:46:08 +0200 (CEST) Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga101.fm.intel.com with ESMTP; 26 May 2015 08:46:08 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.13,499,1427785200"; d="scan'208";a="731885354" Received: from irsmsx154.ger.corp.intel.com ([163.33.192.96]) by fmsmga002.fm.intel.com with ESMTP; 26 May 2015 08:46:07 -0700 Received: from irsmsx105.ger.corp.intel.com ([169.254.7.73]) by IRSMSX154.ger.corp.intel.com ([169.254.12.182]) with mapi id 14.03.0224.002; Tue, 26 May 2015 16:46:07 +0100 From: "Ananyev, Konstantin" To: Stephen Hemminger Thread-Topic: [dpdk-dev] [PATCH 2/5] mbuf: use the reserved 16 bits for double vlan Thread-Index: AQHQl48oHVvv7PLtz0eIGnJC6jZO0J2OSBCAgAARNOD///ntgIAAEmwQ Date: Tue, 26 May 2015 15:46:07 +0000 Message-ID: <2601191342CEEE43887BDE71AB97725821431D05@irsmsx105.ger.corp.intel.com> References: <1430793143-3610-1-git-send-email-helin.zhang@intel.com> <1432629400-25303-1-git-send-email-helin.zhang@intel.com> <1432629400-25303-3-git-send-email-helin.zhang@intel.com> <20150526075515.1bc42ae1@urahara> <2601191342CEEE43887BDE71AB97725821431C8F@irsmsx105.ger.corp.intel.com> <20150526083505.247e5431@urahara> In-Reply-To: <20150526083505.247e5431@urahara> Accept-Language: en-IE, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [163.33.239.182] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Cc: "dev@dpdk.org" Subject: Re: [dpdk-dev] [PATCH 2/5] mbuf: use the reserved 16 bits for double vlan 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: Tue, 26 May 2015 15:46:09 -0000 > -----Original Message----- > From: Stephen Hemminger [mailto:stephen@networkplumber.org] > Sent: Tuesday, May 26, 2015 4:35 PM > To: Ananyev, Konstantin > Cc: Zhang, Helin; dev@dpdk.org > Subject: Re: [dpdk-dev] [PATCH 2/5] mbuf: use the reserved 16 bits for do= uble vlan >=20 > On Tue, 26 May 2015 15:02:51 +0000 > "Ananyev, Konstantin" wrote: >=20 > > Hi Stephen, > > > > > -----Original Message----- > > > From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Stephen Hemminge= r > > > Sent: Tuesday, May 26, 2015 3:55 PM > > > To: Zhang, Helin > > > Cc: dev@dpdk.org > > > Subject: Re: [dpdk-dev] [PATCH 2/5] mbuf: use the reserved 16 bits fo= r double vlan > > > > > > On Tue, 26 May 2015 16:36:37 +0800 > > > Helin Zhang wrote: > > > > > > > Use the reserved 16 bits in rte_mbuf structure for the outer vlan, > > > > also add QinQ offloading flags for both RX and TX sides. > > > > > > > > Signed-off-by: Helin Zhang > > > > > > Yet another change that is much needed, but breaks ABI compatibility. > > > > Why do you think it breaks ABI compatibility? > > As I can see, it uses field that was reserved. > > Konstantin >=20 > Because an application maybe assuming something or reusing the reserved f= ields. But properly behaving application, shouldn't do that right? And for misbehaving ones, why should we care about them? > Yes, it would be dumb of application to do that but from absolute ABI poi= nt > of view it is a change. So, in theory, even adding a new field to the end of rte_mbuf is an ABI br= eakage? Konstantin