From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-we0-f176.google.com (mail-we0-f176.google.com [74.125.82.176]) by dpdk.org (Postfix) with ESMTP id 740D65A76 for ; Tue, 20 Jan 2015 15:00:24 +0100 (CET) Received: by mail-we0-f176.google.com with SMTP id w62so10999907wes.7 for ; Tue, 20 Jan 2015 06:00:24 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:organization :user-agent:in-reply-to:references:mime-version :content-transfer-encoding:content-type; bh=juBpWgz3JL8Bfu9tA2p10V2NIWxnh5S3J3irHyvuLd8=; b=HAjRaMY9G9jRAEXpkRkEzE6PN4Dp/7aC6KpOYbfNp5CVNs8dgKG1isCS3K3ngKl6io 6dmnwOzZS9ASXzS2NgY+j0Hyz8H2PtCyUcKXMnIKouWj+8ygZrYSanlBeokYy/946syQ 9u+eyr+ivWpaNP5zso8bET/NBBVanaPoYlcjYtdjhKNa1OUr3TUEqon0oMYhWmsH1ciT x2GgMezLdcCsGUYUJBadOMJP5SfHNqzc3i7S0cUGTz37txJUqiQlj6UYtH9Y21pi8lhN JYNNlk0qFiEaJq81RjBmZG9OobmOnboz1RCcx9+NSJMACqirUqlyGSNj3528QXxqOGrZ KsZg== X-Gm-Message-State: ALoCoQnOc7FLf+ECcAOhthcp0KIifjpmuHU8+rnWQ9NT1seAyJaZ8tBCaghgurTkQde102B3AJs6 X-Received: by 10.180.207.66 with SMTP id lu2mr46936847wic.13.1421762423896; Tue, 20 Jan 2015 06:00:23 -0800 (PST) Received: from xps13.localnet (guy78-3-82-239-227-177.fbx.proxad.net. [82.239.227.177]) by mx.google.com with ESMTPSA id ej10sm3123329wib.1.2015.01.20.06.00.22 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 20 Jan 2015 06:00:22 -0800 (PST) From: Thomas Monjalon To: Neil Horman Date: Tue, 20 Jan 2015 15:00:01 +0100 Message-ID: <12582729.RuWBbWddAL@xps13> Organization: 6WIND User-Agent: KMail/4.14.3 (Linux/3.17.6-1-ARCH; KDE/4.14.3; x86_64; ; ) In-Reply-To: <1421422389-5473-4-git-send-email-nhorman@tuxdriver.com> References: <1419109299-9603-1-git-send-email-nhorman@tuxdriver.com> <1421422389-5473-1-git-send-email-nhorman@tuxdriver.com> <1421422389-5473-4-git-send-email-nhorman@tuxdriver.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Cc: dev@dpdk.org Subject: Re: [dpdk-dev] [PATCH v5 4/4] docs: Add ABI documentation 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, 20 Jan 2015 14:00:25 -0000 2015-01-16 10:33, Neil Horman: > --- /dev/null > +++ b/doc/abi.txt > @@ -0,0 +1,36 @@ > +ABI policy: > + ABI versions are set at the time of major release labeling, and ABI may > +change multiple times between the last labeling and the HEAD label of the git > +tree without warning > + > + ABI versions, once released are available until such time as their > +deprecation has been noted here for at least one major release cycle, after it > +has been tagged. E.g. the ABI for DPDK 1.8 is shipped, and then the decision to > +remove it is made during the development of DPDK 1.9. The decision will be > +recorded here, shipped with the DPDK 1.9 release, and actually removed when DPDK > +1.10 ships. > + > + ABI versions may be deprecated in whole, or in part as needed by a given > +update. > + > + Some ABI changes may be too significant to reasonably maintain multiple > +versions of. In those events ABI's may be updated without backward > +compatibility provided. The requirements for doing so are: > + 1) At least 3 acknoweldgements of the need on the dpdk.org > + 2) A full deprecation cycle must be made to offer downstream consumers > +sufficient warning of the change. E.g. if dpdk 2.0 is under development when > +the change is proposed, a deprecation notice must be added to this file, and > +released with dpdk 2.0. Then the change may be incorporated for dpdk 2.1 > + 3) The LIBABIVER variable in the makefilei(s) where the ABI changes are > +incorporated must be incremented in parallel with the ABI changes themselves > + > + Note that the above process for ABI deprecation should not be undertaken > +lightly. ABI stability is extreemely important for downstream consumers of the > +DPDK, especially when distributed in shared object form. Every effort should be > +made to preserve ABI whenever possible. For instance, reorganizing public > +structure field for astetic or readability purposes should be avoided as it will astetic? typo? > +cause ABI breakage. Only significant (e.g. performance) reasons should be seen > +as cause to alter ABI. > + > +Deprecation Notices: Neil, are you sure it's a good idea to put deprecations notices here instead of release notes? I'm also thinking that we need to add more things in this doc: - case of macros/constant deprecation (API only) - case of structure update: must be renamed to provide ABI compatibility? Do you think we can have a tool to test the ABI compatibility by building examples/apps of previous version and checking them with built DSO of current version? Thanks -- Thomas