From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by dpdk.org (Postfix) with ESMTP id 9030295AA for ; Mon, 7 Dec 2015 12:41:43 +0100 (CET) Received: from int-mx14.intmail.prod.int.phx2.redhat.com (int-mx14.intmail.prod.int.phx2.redhat.com [10.5.11.27]) by mx1.redhat.com (Postfix) with ESMTPS id F0ECDC001247; Mon, 7 Dec 2015 11:41:42 +0000 (UTC) Received: from sopuli.koti.laiskiainen.org (vpn1-5-85.ams2.redhat.com [10.36.5.85]) by int-mx14.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id tB7BffoD003740; Mon, 7 Dec 2015 06:41:41 -0500 To: Thomas Monjalon References: <1449027793-30975-1-git-send-email-yuanhan.liu@linux.intel.com> <2679675.c6cKM9bBsr@xps13> <5665275A.6020308@redhat.com> <8246076.3G1fmNTuPH@xps13> From: Panu Matilainen Message-ID: <56657074.7000206@redhat.com> Date: Mon, 7 Dec 2015 13:41:40 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.4.0 MIME-Version: 1.0 In-Reply-To: <8246076.3G1fmNTuPH@xps13> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.68 on 10.5.11.27 Cc: dev@dpdk.org, Victor Kaplansky , "Michael S. Tsirkin" Subject: Re: [dpdk-dev] [PATCH 1/4] vhost: handle VHOST_USER_SET_LOG_BASE request 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: Mon, 07 Dec 2015 11:41:43 -0000 On 12/07/2015 01:28 PM, Thomas Monjalon wrote: > 2015-12-07 08:29, Panu Matilainen: >> On 12/07/2015 01:07 AM, Thomas Monjalon wrote: >>> 2015-12-02 15:53, Panu Matilainen: >>>> This (and other changes in patch 2 breaks the librte_vhost ABI again, so >>>> you'd need to at least add a deprecation note to 2.2 to be able to do it >>>> in 2.3 at all according to the ABI policy. >>>> >>>> Perhaps a better option would be adding some padding to the structs now >>>> for 2.2 since the vhost ABI is broken there anyway. That would at least >>>> give a chance to keep it compatible from 2.2 to 2.3. >>> >>> Please could you point where the vhost ABI is broken in 2.2? >>> >> >> The vhost ABI break was announced for DPDK 2.2 in commit >> 3c848bd7b1c6f4f681b833322a748fdefbb5fb2d: > [...] >> So the ABI process was properly followed, except for actually bumping >> LIBABIVER. Bumping LIBABIVER is mentioned in >> doc/guides/contributing/versioning.rst but it doesn't specify *when* >> this should be done, eg should the first patch breaking the ABI bump it >> or should it done be shortly before the next stable release, or >> something else. As it is, it seems a bit too easy to simply forget. > > I thought it was not needed to explicitly say that commits must be atomic > and we do not have to wait to do the required changes. The "problem" is that during a development cycle, an ABI could be broken several times but LIBABIVER should only be bumped once. So ABI breaking commits will often not be atomic wrt LIBABIVER, no matter which way its done. For example libtool recommendation is that library versions are updated only just before public releases: https://www.gnu.org/software/libtool/manual/html_node/Updating-version-info.html#Updating-version-info - Panu - > In this case, I've missed it when reviewing the vhost patches breaking the > ABI. >