From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dpdk.org (dpdk.org [92.243.14.124]) by inbox.dpdk.org (Postfix) with ESMTP id B40F8A04F1; Tue, 10 Dec 2019 13:41:01 +0100 (CET) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id 0646137A2; Tue, 10 Dec 2019 13:41:01 +0100 (CET) Received: from mga06.intel.com (mga06.intel.com [134.134.136.31]) by dpdk.org (Postfix) with ESMTP id C7FC123D for ; Tue, 10 Dec 2019 13:40:58 +0100 (CET) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by orsmga104.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 10 Dec 2019 04:40:56 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.69,299,1571727600"; d="scan'208";a="244833429" Received: from fyigit-mobl.ger.corp.intel.com (HELO [10.237.221.96]) ([10.237.221.96]) by fmsmga002.fm.intel.com with ESMTP; 10 Dec 2019 04:40:54 -0800 To: Bruce Richardson Cc: "Kinsella, Ray" , Thomas Monjalon , David Marchand , Luca Boccassi , Christian Ehrhardt , Timothy Redaelli , Kevin Traynor , dpdk-dev , "Laatz, Kevin" , Andrew Rybchenko , Neil Horman References: <5df1a33b-b338-bde1-6834-e8b5fbe65a04@intel.com> <20191210120455.GB103@bricha3-MOBL.ger.corp.intel.com> From: Ferruh Yigit Autocrypt: addr=ferruh.yigit@intel.com; prefer-encrypt=mutual; keydata= mQINBFXZCFABEADCujshBOAaqPZpwShdkzkyGpJ15lmxiSr3jVMqOtQS/sB3FYLT0/d3+bvy qbL9YnlbPyRvZfnP3pXiKwkRoR1RJwEo2BOf6hxdzTmLRtGtwWzI9MwrUPj6n/ldiD58VAGQ +iR1I/z9UBUN/ZMksElA2D7Jgg7vZ78iKwNnd+vLBD6I61kVrZ45Vjo3r+pPOByUBXOUlxp9 GWEKKIrJ4eogqkVNSixN16VYK7xR+5OUkBYUO+sE6etSxCr7BahMPKxH+XPlZZjKrxciaWQb +dElz3Ab4Opl+ZT/bK2huX+W+NJBEBVzjTkhjSTjcyRdxvS1gwWRuXqAml/sh+KQjPV1PPHF YK5LcqLkle+OKTCa82OvUb7cr+ALxATIZXQkgmn+zFT8UzSS3aiBBohg3BtbTIWy51jNlYdy ezUZ4UxKSsFuUTPt+JjHQBvF7WKbmNGS3fCid5Iag4tWOfZoqiCNzxApkVugltxoc6rG2TyX CmI2rP0mQ0GOsGXA3+3c1MCdQFzdIn/5tLBZyKy4F54UFo35eOX8/g7OaE+xrgY/4bZjpxC1 1pd66AAtKb3aNXpHvIfkVV6NYloo52H+FUE5ZDPNCGD0/btFGPWmWRmkPybzColTy7fmPaGz cBcEEqHK4T0aY4UJmE7Ylvg255Kz7s6wGZe6IR3N0cKNv++O7QARAQABtCVGZXJydWggWWln aXQgPGZlcnJ1aC55aWdpdEBpbnRlbC5jb20+iQJUBBMBCgA+AhsDAh4BAheABQsJCAcDBRUK CQgLBRYCAwEAFiEE0jZTh0IuwoTjmYHH+TPrQ98TYR8FAl1meboFCQlupOoACgkQ+TPrQ98T YR9ACBAAv2tomhyxY0Tp9Up7mNGLfEdBu/7joB/vIdqMRv63ojkwr9orQq5V16V/25+JEAD0 60cKodBDM6HdUvqLHatS8fooWRueSXHKYwJ3vxyB2tWDyZrLzLI1jxEvunGodoIzUOtum0Ce gPynnfQCelXBja0BwLXJMplM6TY1wXX22ap0ZViC0m714U5U4LQpzjabtFtjT8qOUR6L7hfy YQ72PBuktGb00UR/N5UrR6GqB0x4W41aZBHXfUQnvWIMmmCrRUJX36hOTYBzh+x86ULgg7H2 1499tA4o6rvE13FiGccplBNWCAIroAe/G11rdoN5NBgYVXu++38gTa/MBmIt6zRi6ch15oLA Ln2vHOdqhrgDuxjhMpG2bpNE36DG/V9WWyWdIRlz3NYPCDM/S3anbHlhjStXHOz1uHOnerXM 1jEjcsvmj1vSyYoQMyRcRJmBZLrekvgZeh7nJzbPHxtth8M7AoqiZ/o/BpYU+0xZ+J5/szWZ aYxxmIRu5ejFf+Wn9s5eXNHmyqxBidpCWvcbKYDBnkw2+Y9E5YTpL0mS0dCCOlrO7gca27ux ybtbj84aaW1g0CfIlUnOtHgMCmz6zPXThb+A8H8j3O6qmPoVqT3qnq3Uhy6GOoH8Fdu2Vchh TWiF5yo+pvUagQP6LpslffufSnu+RKAagkj7/RSuZV25Ag0EV9ZMvgEQAKc0Db17xNqtSwEv mfp4tkddwW9XA0tWWKtY4KUdd/jijYqc3fDD54ESYpV8QWj0xK4YM0dLxnDU2IYxjEshSB1T qAatVWz9WtBYvzalsyTqMKP3w34FciuL7orXP4AibPtrHuIXWQOBECcVZTTOdZYGAzaYzxiA ONzF9eTiwIqe9/oaOjTwTLnOarHt16QApTYQSnxDUQljeNvKYt1lZE/gAUUxNLWsYyTT+22/ vU0GDUahsJxs1+f1yEr+OGrFiEAmqrzpF0lCS3f/3HVTU6rS9cK3glVUeaTF4+1SK5ZNO35p iVQCwphmxa+dwTG/DvvHYCtgOZorTJ+OHfvCnSVjsM4kcXGjJPy3JZmUtyL9UxEbYlrffGPQ I3gLXIGD5AN5XdAXFCjjaID/KR1c9RHd7Oaw0Pdcq9UtMLgM1vdX8RlDuMGPrj5sQrRVbgYH fVU/TQCk1C9KhzOwg4Ap2T3tE1umY/DqrXQgsgH71PXFucVjOyHMYXXugLT8YQ0gcBPHy9mZ qw5mgOI5lCl6d4uCcUT0l/OEtPG/rA1lxz8ctdFBVOQOxCvwRG2QCgcJ/UTn5vlivul+cThi 6ERPvjqjblLncQtRg8izj2qgmwQkvfj+h7Ex88bI8iWtu5+I3K3LmNz/UxHBSWEmUnkg4fJl Rr7oItHsZ0ia6wWQ8lQnABEBAAGJAjwEGAEKACYCGwwWIQTSNlOHQi7ChOOZgcf5M+tD3xNh HwUCXWZ5wAUJB3FgggAKCRD5M+tD3xNhH2O+D/9OEz62YuJQLuIuOfL67eFTIB5/1+0j8Tsu o2psca1PUQ61SZJZOMl6VwNxpdvEaolVdrpnSxUF31kPEvR0Igy8HysQ11pj8AcgH0a9FrvU /8k2Roccd2ZIdpNLkirGFZR7LtRw41Kt1Jg+lafI0efkiHKMT/6D/P1EUp1RxOBNtWGV2hrd 0Yg9ds+VMphHHU69fDH02SwgpvXwG8Qm14Zi5WQ66R4CtTkHuYtA63sS17vMl8fDuTCtvfPF HzvdJLIhDYN3Mm1oMjKLlq4PUdYh68Fiwm+boJoBUFGuregJFlO3hM7uHBDhSEnXQr5mqpPM 6R/7Q5BjAxrwVBisH0yQGjsWlnysRWNfExAE2sRePSl0or9q19ddkRYltl6X4FDUXy2DTXa9 a+Fw4e1EvmcF3PjmTYs9IE3Vc64CRQXkhujcN4ZZh5lvOpU8WgyDxFq7bavFnSS6kx7Tk29/ wNJBp+cf9qsQxLbqhW5kfORuZGecus0TLcmpZEFKKjTJBK9gELRBB/zoN3j41hlEl7uTUXTI JQFLhpsFlEdKLujyvT/aCwP3XWT+B2uZDKrMAElF6ltpTxI53JYi22WO7NH7MR16Fhi4R6vh FHNBOkiAhUpoXRZXaCR6+X4qwA8CwHGqHRBfYFSU/Ulq1ZLR+S3hNj2mbnSx0lBs1eEqe2vh cA== Message-ID: <36590631-c424-f466-cd37-a759e3fc306c@intel.com> Date: Tue, 10 Dec 2019 12:40:53 +0000 MIME-Version: 1.0 In-Reply-To: <20191210120455.GB103@bricha3-MOBL.ger.corp.intel.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Subject: Re: [dpdk-dev] How to manage new APIs added after major ABI release? X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On 12/10/2019 12:04 PM, Bruce Richardson wrote: > On Tue, Dec 10, 2019 at 11:56:28AM +0000, Ferruh Yigit wrote: >> Hi, >> >> With new process, the major ABI releases will be compatible until it is >> deprecated (until next LTS for now), >> like current ABI version is 20 in DPDK_19.11 and DPDK versions until DPDK_20.11 >> will be ABI compatible with this version. >> >> But if we introduce a new API after major ABI, say in 20.02 release, are we >> allowed to break the ABI for that API before DPDK_20.11? >> >> If we allow it break, following problem will be observed: >> Assume an application using .so.20.1 library, and using the new API introduced >> in 20.02, lets say foo(), >> but when application switches to .so.20.2 (released via DPDK_20.05), application >> will fail because of ABI breakage in foo(). >> >> I think it is fair that application expects forward compatibility in minor >> versions of a shared library. >> Like if application linked against .so.20.2, fair to expect .so.20.3, .so.20.4 >> etc will work fine. I think currently only .so.20.0 is fully forward compatible. >> >> If we all agree on this, we may need to tweak the process a little, but before >> diving into implementation details, I would like to be sure we are in same page. >> > > Well, any new API's generally come in as experimental, in which case > changes are allowed, and breakage can be expected. If they are not > experiemental, then the ABI policy applies to them in that they cannot > change since they are part of the .21 ABI, even if that ABI is not fully > complete yet. For any application only using stable, non-experimental > functions, forward compatibility must be maintained IMHO. > Talking about not experimental APIs, experimental ones free from the process. And when and API added in 20.02 (ABI_20.1) it is kind of still ABI_20, because it should be supported for following ABI_20.x, instead of calling it ABI_21, and this minor tweak (and mind shift) in .map files can be our solution.