From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: <helin.zhang@intel.com> Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by dpdk.org (Postfix) with ESMTP id E8F4A5A9A for <dev@dpdk.org>; Wed, 27 May 2015 03:07:57 +0200 (CEST) Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by orsmga102.jf.intel.com with ESMTP; 26 May 2015 18:07:46 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.13,502,1427785200"; d="scan'208";a="732166887" Received: from pgsmsx107.gar.corp.intel.com ([10.221.44.105]) by fmsmga002.fm.intel.com with ESMTP; 26 May 2015 18:07:44 -0700 Received: from kmsmsx154.gar.corp.intel.com (172.21.73.14) by PGSMSX107.gar.corp.intel.com (10.221.44.105) with Microsoft SMTP Server (TLS) id 14.3.224.2; Wed, 27 May 2015 09:07:44 +0800 Received: from shsmsx152.ccr.corp.intel.com (10.239.6.52) by KMSMSX154.gar.corp.intel.com (172.21.73.14) with Microsoft SMTP Server (TLS) id 14.3.224.2; Wed, 27 May 2015 09:07:43 +0800 Received: from shsmsx104.ccr.corp.intel.com ([169.254.5.94]) by SHSMSX152.ccr.corp.intel.com ([169.254.6.50]) with mapi id 14.03.0224.002; Wed, 27 May 2015 09:07:42 +0800 From: "Zhang, Helin" <helin.zhang@intel.com> To: "Ananyev, Konstantin" <konstantin.ananyev@intel.com>, Stephen Hemminger <stephen@networkplumber.org> Thread-Topic: [dpdk-dev] [PATCH 2/5] mbuf: use the reserved 16 bits for double vlan Thread-Index: AQHQl8QI4FAnleAkdEi17M46qfgc8p2N1G2AgAAJAoCAAAMVgIABIjPg Date: Wed, 27 May 2015 01:07:41 +0000 Message-ID: <F35DEAC7BCE34641BA9FAC6BCA4A12E70A86C244@SHSMSX104.ccr.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> <2601191342CEEE43887BDE71AB97725821431D05@irsmsx105.ger.corp.intel.com> In-Reply-To: <2601191342CEEE43887BDE71AB97725821431D05@irsmsx105.ger.corp.intel.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.239.127.40] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Cc: "dev@dpdk.org" <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 <dev.dpdk.org> List-Unsubscribe: <http://dpdk.org/ml/options/dev>, <mailto:dev-request@dpdk.org?subject=unsubscribe> List-Archive: <http://dpdk.org/ml/archives/dev/> List-Post: <mailto:dev@dpdk.org> List-Help: <mailto:dev-request@dpdk.org?subject=help> List-Subscribe: <http://dpdk.org/ml/listinfo/dev>, <mailto:dev-request@dpdk.org?subject=subscribe> X-List-Received-Date: Wed, 27 May 2015 01:07:58 -0000 > -----Original Message----- > From: Ananyev, Konstantin > Sent: Tuesday, May 26, 2015 11:46 PM > To: Stephen Hemminger > Cc: Zhang, Helin; dev@dpdk.org > Subject: RE: [dpdk-dev] [PATCH 2/5] mbuf: use the reserved 16 bits for > double vlan >=20 >=20 >=20 > > -----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 > > double vlan > > > > On Tue, 26 May 2015 15:02:51 +0000 > > "Ananyev, Konstantin" <konstantin.ananyev@intel.com> wrote: > > > > > Hi Stephen, > > > > > > > -----Original Message----- > > > > From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Stephen > > > > Hemminger > > > > 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 > > > > for double vlan > > > > > > > > On Tue, 26 May 2015 16:36:37 +0800 Helin Zhang > > > > <helin.zhang@intel.com> 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 <helin.zhang@intel.com> > > > > > > > > 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 > > > > Because an application maybe assuming something or reusing the > reserved fields. >=20 > But properly behaving application, shouldn't do that right? > And for misbehaving ones, why should we care about them? For any reserved bits, I think all application users should avoid touching = it, as it is reserved for future use, or some special reason. Otherwise, un-predicted behavior can be expected. Regards, Helin >=20 > > Yes, it would be dumb of application to do that but from absolute ABI > > point of view it is a change. >=20 > So, in theory, even adding a new field to the end of rte_mbuf is an ABI > breakage? > Konstantin