From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: <bruce.richardson@intel.com> Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by dpdk.org (Postfix) with ESMTP id 2CF1D1D90 for <dev@dpdk.org>; Tue, 12 Dec 2017 15:07:56 +0100 (CET) X-Amp-Result: UNSCANNABLE X-Amp-File-Uploaded: False Received: from orsmga003.jf.intel.com ([10.7.209.27]) by orsmga102.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 12 Dec 2017 06:07:55 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.45,395,1508828400"; d="scan'208";a="11677436" Received: from bricha3-mobl3.ger.corp.intel.com ([10.237.221.106]) by orsmga003.jf.intel.com with SMTP; 12 Dec 2017 06:07:53 -0800 Received: by (sSMTP sendmail emulation); Tue, 12 Dec 2017 14:07:52 +0000 Date: Tue, 12 Dec 2017 14:07:52 +0000 From: Bruce Richardson <bruce.richardson@intel.com> To: Neil Horman <nhorman@tuxdriver.com> Cc: dev@dpdk.org, thomas@monjalon.net, john.mcnamara@intel.com Message-ID: <20171212140751.GA7280@bricha3-MOBL3.ger.corp.intel.com> References: <20171201185628.16261-1-nhorman@tuxdriver.com> <20171211193619.21643-1-nhorman@tuxdriver.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20171211193619.21643-1-nhorman@tuxdriver.com> Organization: Intel Research and Development Ireland Ltd. User-Agent: Mutt/1.9.1 (2017-09-22) Subject: Re: [dpdk-dev] [PATCHv3 0/4] dpdk: enhance EXPERIMENTAL api tagging X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions <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: Tue, 12 Dec 2017 14:07:57 -0000 On Mon, Dec 11, 2017 at 02:36:15PM -0500, Neil Horman wrote: > Hey all- > A few days ago, I was lamenting the fact that, when reviewing patches I > would frequently complain about ABI changes that were actually considered safe > because they were part of the EXPERIMENTAL api set. John M. asked me then what > I might do to improve the situation, and the following patch set is a proposal > that I've come up with. > > In thinking about the problem I identified two issues that I think we > can improve on in this area: > > 1) Make experimental api calls more visible in the source code. That is to say, > when reviewing patches, it would be nice to have some sort of visual reference > that indicates that the changes being made are part of an experimental API and > therefore ABI concerns need not be addressed > > 2) Make experimenal api usage more visible to consumers of the DPDK, so that > they can make a more informed decision about the API's they consume in their > application. We make an effort to document all the experimental API's, but > there is no guarantee that a user will check the documentation before making use > of a new library. > > This patch set attempts to achieve both of the above goals. To do this I've > added an __experimental macro tag, suitable for inserting into api forward > declarations and definitions. > > The presence of the tag in the header and c files where the api code resides > increases the likelyhood that any patch submitted against them will include the > tag in the context, making it clear to reviewers that ABI stability isn't a > concern here. > > > Also, This tag marks each function it is used on with an attibute causing any > use of the fuction to emit a warning during the build > with a message indicating that the API call in question is not yet part of the > stable interface. Developers can then make an informed decision to suppress > that warning or not. > > Because there is internal use of several experimental API's, this set also > includes a new override macro ALLOW_EXPERIMENTAL_APIS to automatically > suprress these warnings. I think its fair to assume that, for internal use, we > almost always want to suppress these warnings, as by definition any change to > the apis (even their removal) must be done in parallel with an appropriate > change in the calling locations, lest the dpdk build itself break. > > Neil > > --- > Change Notes: > v2) > * Cleaned up checkpatch errors > * Added Allowance for building experimental on BSD > * Swapped Patch 3 and 4 so that we didn't have a commit level that issued > warnings/errors without need > > v3) > * On suggestion from Bruce, modify ALLOW_EXPERIMENTAL_APIS to be defined in > CFLAGS rather than a makefile variable. This is more flexible in that it > allows us to suppress this specific feature rather than all uses of the > deprecated attribute, as we might use it for other features in the furute > Despite the fact that this is making yet more work for porting to a new build system, I think this is a good idea to have. As such, Acked-by: Bruce Richardson <bruce.richardson@intel.com>