From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) by dpdk.org (Postfix) with ESMTP id 7EC8E3772 for ; Tue, 19 Jul 2016 17:09:06 +0200 (CEST) Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga103.fm.intel.com with ESMTP; 19 Jul 2016 08:07:13 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.28,390,1464678000"; d="scan'208";a="998322955" Received: from irsmsx102.ger.corp.intel.com ([163.33.3.155]) by orsmga001.jf.intel.com with ESMTP; 19 Jul 2016 08:07:12 -0700 Received: from irsmsx103.ger.corp.intel.com ([169.254.3.204]) by IRSMSX102.ger.corp.intel.com ([169.254.2.123]) with mapi id 14.03.0248.002; Tue, 19 Jul 2016 16:07:11 +0100 From: "Richardson, Bruce" To: Olivier Matz CC: "dev@dpdk.org" , "jerin.jacob@caviumnetworks.com" , "thomas.monjalon@6wind.com" Thread-Topic: [dpdk-dev] [PATCH] doc: announce ABI change for mbuf structure Thread-Index: AQHR4cYkU9BOW4kYiEirU10CFVu+iqAf02MA///13YCAABEVIA== Date: Tue, 19 Jul 2016 15:07:10 +0000 Message-ID: <59AF69C657FD0841A61C55336867B5B035AA7BC6@IRSMSX103.ger.corp.intel.com> References: <1468936875-1652-1-git-send-email-olivier.matz@6wind.com> <20160719144018.GA10912@bricha3-MOBL3> In-Reply-To: Accept-Language: en-GB, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-titus-metadata-40: eyJDYXRlZ29yeUxhYmVscyI6IiIsIk1ldGFkYXRhIjp7Im5zIjoiaHR0cDpcL1wvd3d3LnRpdHVzLmNvbVwvbnNcL0ludGVsMyIsImlkIjoiM2FkZWFhMGYtY2IxNS00YmFhLWI5MTUtNTY5ZDYyY2NjNGJjIiwicHJvcHMiOlt7Im4iOiJDVFBDbGFzc2lmaWNhdGlvbiIsInZhbHMiOlt7InZhbHVlIjoiQ1RQX0lDIn1dfV19LCJTdWJqZWN0TGFiZWxzIjpbXSwiVE1DVmVyc2lvbiI6IjE1LjkuNi42IiwiVHJ1c3RlZExhYmVsSGFzaCI6Ilp4VGFDVVZyd1VpOStIOWFzXC9rZ1VLWDRTTU9VMUUzUFwvNjJEeHJwSzFubz0ifQ== x-ctpclassification: CTP_IC x-originating-ip: [163.33.239.180] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Subject: Re: [dpdk-dev] [PATCH] doc: announce ABI change for mbuf structure 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, 19 Jul 2016 15:09:07 -0000 > -----Original Message----- > From: Olivier Matz [mailto:olivier.matz@6wind.com] > Sent: Tuesday, July 19, 2016 4:04 PM > To: Richardson, Bruce > Cc: dev@dpdk.org; jerin.jacob@caviumnetworks.com; > thomas.monjalon@6wind.com > Subject: Re: [dpdk-dev] [PATCH] doc: announce ABI change for mbuf > structure >=20 > Hi Bruce, >=20 > On 07/19/2016 04:40 PM, Bruce Richardson wrote: > > On Tue, Jul 19, 2016 at 04:01:15PM +0200, Olivier Matz wrote: > >> For 16.11, the mbuf structure will be modified implying ABI breakage. > >> Some discussions already took place here: > >> http://www.dpdk.org/dev/patchwork/patch/12878/ > >> > >> Signed-off-by: Olivier Matz > >> --- > >> doc/guides/rel_notes/deprecation.rst | 6 ++++++ > >> 1 file changed, 6 insertions(+) > >> > >> diff --git a/doc/guides/rel_notes/deprecation.rst > >> b/doc/guides/rel_notes/deprecation.rst > >> index f502f86..2245bc2 100644 > >> --- a/doc/guides/rel_notes/deprecation.rst > >> +++ b/doc/guides/rel_notes/deprecation.rst > >> @@ -41,3 +41,9 @@ Deprecation Notices > >> * The mempool functions for single/multi producer/consumer are > deprecated and > >> will be removed in 16.11. > >> It is replaced by rte_mempool_generic_get/put functions. > >> + > >> +* ABI changes are planned for 16.11 in the ``rte_mbuf`` structure: > >> +some > >> + fields will be reordered to facilitate the writing of > >> +``data_off``, > >> + ``refcnt``, and ``nb_segs`` in one operation. Indeed, some > >> +platforms > >> + have an overhead if the store address is not naturally aligned. > >> +The > >> + useless ``port`` field will also be removed at the same occasion. > >> -- > > > > Have we fully bottomed out on the mbuf changes. I'm not sure that once > > patches start getting considered for merge, new opinions may come > > forward. For instance, is the "port" field really "useless"? > > > > Would it not be better to put in a less specific deprecation notice? > > What happens if this notice goes in and the final changes are > > different from those called out here? >=20 > Yes, you are right. What about the following text? >=20 > ABI changes are planned for 16.11 in the ``rte_mbuf`` structure: some > fields may be reordered to facilitate the writing of ``data_off``, > ``refcnt``, and ``nb_segs`` in one operation. Indeed, some platforms have > an overhead if the store address is not naturally aligned. The ``port`` > field may also be removed at the same occasion. >=20 Better. Two suggestions: 1. change "Indeed" to "because" and join the sentences. 2. change the last sentence to be even more general: "Other mbuf fields, su= ch as the port field, may be moved or removed as part of this mbuf work". /Bruce