From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from out2-smtp.messagingengine.com (out2-smtp.messagingengine.com [66.111.4.26]) by dpdk.org (Postfix) with ESMTP id 4DE11728E for ; Thu, 8 Mar 2018 22:34:31 +0100 (CET) Received: from compute1.internal (compute1.nyi.internal [10.202.2.41]) by mailout.nyi.internal (Postfix) with ESMTP id BE1BA20B16; Thu, 8 Mar 2018 16:34:30 -0500 (EST) Received: from frontend1 ([10.202.2.160]) by compute1.internal (MEProxy); Thu, 08 Mar 2018 16:34:30 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=monjalon.net; h= cc:content-transfer-encoding:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to:x-me-sender :x-me-sender:x-sasl-enc; s=mesmtp; bh=evrNxW7a6PpCruht2AQeTluuSf Zs0BaX+iZVSNsF3DE=; b=rBaaYzL0V6YuVV4WmCxLvRQHcvtBZH5nRxuIpR8Kju MMhx1dcsEMSOKIj3JyKIXLTC10X0BVMS/o+UwlZGlOUTY40QOBS3UE7mYZw6XuiM WRY/fLuMUwRRGo/DlYnoqZ6l2/+ajlTv2T37ovT3Ik0RAZ+U25vq7hefNph0mLyY 0= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-transfer-encoding:content-type :date:from:in-reply-to:message-id:mime-version:references :subject:to:x-me-sender:x-me-sender:x-sasl-enc; s=fm2; bh=evrNxW 7a6PpCruht2AQeTluuSfZs0BaX+iZVSNsF3DE=; b=cizOZw9ZA4IN/U7zQBQxwg VO6bG7/EsNe2psTKPE8F0lSOXirDfSpl2aNa3hmbflp7Zv4AF+UctI2YN/WDb2AU 1dPxcxJK1KgmH4+OF6zBPPf2yl0W/9VpHZj4Sy1lOu3xwrbHcOqFd1SRgIIVWojq 4Ku/ck6P+FXNQDWqJRq9AADcZin1BLdVmq9rcA3gbEOFqPlhBq/icLOlddd9mc12 W/E5VIcgGljKjx10J1w24Xc72hx1mq+9OXHVEzO0ilCu1wo46gYtiMoZp53NLYDz YsXYDgEizOZW36Q9ZHhKHZsCbU/lkyW9BMfgMbgEZA4GTio8o01xQ3jwNQa5D4ew == X-ME-Sender: Received: from xps.localnet (184.203.134.77.rev.sfr.net [77.134.203.184]) by mail.messagingengine.com (Postfix) with ESMTPA id CB2107E171; Thu, 8 Mar 2018 16:34:29 -0500 (EST) From: Thomas Monjalon To: Neil Horman Cc: Ferruh Yigit , John McNamara , Marko Kovacevic , dev@dpdk.org, Luca Boccassi , Christian Ehrhardt Date: Thu, 08 Mar 2018 22:34:14 +0100 Message-ID: <2251603.sn1Xas34Et@xps> In-Reply-To: <20180308194039.GB32578@hmswarspite.think-freely.org> References: <20180307174422.118291-1-ferruh.yigit@intel.com> <4097404.y7j9CXhnSi@xps> <20180308194039.GB32578@hmswarspite.think-freely.org> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Subject: Re: [dpdk-dev] [RFC] config: remove RTE_NEXT_ABI 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: , X-List-Received-Date: Thu, 08 Mar 2018 21:34:31 -0000 08/03/2018 20:40, Neil Horman: > On Thu, Mar 08, 2018 at 05:04:01PM +0100, Thomas Monjalon wrote: > > 08/03/2018 16:35, Neil Horman: > > > On Thu, Mar 08, 2018 at 04:17:00PM +0100, Thomas Monjalon wrote: > > > > 08/03/2018 12:43, Ferruh Yigit: > > > > > On 3/8/2018 8:05 AM, Thomas Monjalon wrote: > > > > > > 07/03/2018 18:44, Ferruh Yigit: > > > > > >> After experimental API process defined do we still need RTE_NEXT_ABI > > > > > >> config and process which has similar targets? > > > > > > > > > > > > They are different targets. > > > > > > Experimental API is always enabled but may be avoided by applications. > > > > > > Next ABI can be used to break ABI without notice and disabled to keep > > > > > > old ABI compatibility. It is almost never used because it is preferred > > > > > > to keep ABI compatibility with rte_compat macros, or wait a deprecation > > > > > > period after notice. > > > > > > > > > > OK, I see. > > > > > > > > > > Shouldn't we disable it by default at least? Otherwise who is not paying > > > > > attention to this config option will get and ABI/API break. > > > > > > > > Yes I think you are right, it can be disabled by default. > > > > > > > I would agree, there seems to be overlap here, and the experimental tagging can > > > cover what the NEXT_API flag is meant to do. It can be removed I think. > > > > It is not NEXT_API but NEXT_ABI. > Sorry, typo, though I'm sure you got that, since the former doesn't exist, > right? > > Why do you think it overlaps experimental API tagging? > > I assert that because the compat lib has macros to map common symbols to version > specific ones. That is to say, if you change a data structure, you can setup > the API calls that use said structure such that version 1 or the symbol maps to > an internal function that uses the old structure, while version 2 maps to an > internal function that uses the new symbol > > That is to say, if you're planning on introducing ABI changes, the experimental > API tagging can be used to implement what the NEXT_ABI macro does. It is a different usage. Experimental API tagging is for new functions. rte_compat is used to avoid breaking the ABI when changing old code. NEXT_ABI has been used in the past to disable an ABI breakage, which was not possible to mitigate with rte_compat because impacting too many functions. I am not saying that I like NEXT_ABI, but it could be useful exceptionnally.