From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <stable-bounces@dpdk.org>
Received: from dpdk.org (dpdk.org [92.243.14.124])
	by dpdk.space (Postfix) with ESMTP id 2DA69A05D3
	for <public@inbox.dpdk.org>; Wed, 22 May 2019 16:33:52 +0200 (CEST)
Received: from [92.243.14.124] (localhost [127.0.0.1])
	by dpdk.org (Postfix) with ESMTP id 0BA3558EC;
	Wed, 22 May 2019 16:33:52 +0200 (CEST)
Received: from smtp.tuxdriver.com (charlotte.tuxdriver.com [70.61.120.58])
 by dpdk.org (Postfix) with ESMTP id 903614C80;
 Wed, 22 May 2019 16:33:48 +0200 (CEST)
Received: from cpe-2606-a000-111b-405a-0-0-0-162e.dyn6.twc.com
 ([2606:a000:111b:405a::162e] helo=localhost)
 by smtp.tuxdriver.com with esmtpsa (TLSv1:AES256-SHA:256) (Exim 4.63)
 (envelope-from <nhorman@tuxdriver.com>)
 id 1hTSJE-0002Fc-TR; Wed, 22 May 2019 10:33:43 -0400
Date: Wed, 22 May 2019 10:33:09 -0400
From: Neil Horman <nhorman@tuxdriver.com>
To: Thomas Monjalon <thomas@monjalon.net>
Cc: Jerin Jacob Kollanukkaran <jerinj@marvell.com>,
 "dev@dpdk.org" <dev@dpdk.org>, "stable@dpdk.org" <stable@dpdk.org>
Message-ID: <20190522143309.GE18629@hmswarspite.think-freely.org>
References: <BYAPR18MB242431129975072BBC7419E1C8000@BYAPR18MB2424.namprd18.prod.outlook.com>
 <20190522134056.GC18629@hmswarspite.think-freely.org>
 <2338315.GuTbrZZCDE@xps>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <2338315.GuTbrZZCDE@xps>
User-Agent: Mutt/1.11.3 (2019-02-01)
X-Spam-Score: -2.9 (--)
X-Spam-Status: No
Subject: Re: [dpdk-stable] [dpdk-dev] [PATCH] devtools: skip the symbol
 check when map file under drivers
X-BeenThere: stable@dpdk.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: patches for DPDK stable branches <stable.dpdk.org>
List-Unsubscribe: <https://mails.dpdk.org/options/stable>,
 <mailto:stable-request@dpdk.org?subject=unsubscribe>
List-Archive: <http://mails.dpdk.org/archives/stable/>
List-Post: <mailto:stable@dpdk.org>
List-Help: <mailto:stable-request@dpdk.org?subject=help>
List-Subscribe: <https://mails.dpdk.org/listinfo/stable>,
 <mailto:stable-request@dpdk.org?subject=subscribe>
Errors-To: stable-bounces@dpdk.org
Sender: "stable" <stable-bounces@dpdk.org>

On Wed, May 22, 2019 at 04:12:40PM +0200, Thomas Monjalon wrote:
> 22/05/2019 15:40, Neil Horman:
> > On Wed, May 22, 2019 at 01:12:34PM +0000, Jerin Jacob Kollanukkaran wrote:
> > > From: Neil Horman <nhorman@tuxdriver.com>
> > > > On Wed, May 22, 2019 at 03:05:54AM +0000, Jerin Jacob Kollanukkaran
> > > > wrote:
> > > > > From: Neil Horman <nhorman@tuxdriver.com>
> > > > > > On Wed, May 22, 2019 at 01:26:28AM +0530, jerinj@marvell.com wrote:
> > > > > > > From: Jerin Jacob <jerinj@marvell.com>
> > > > > > >
> > > > > > > Drivers do not have ABI.
> > > > > > > Skip the symbol check if map file under drivers directory.
> > > > > > >
> > > > > > > Fixes: 4bec48184e33 ("devtools: add checks for ABI symbol
> > > > > > > addition")
> > > > > > >
> > > > > > > Cc: stable@dpdk.org
> > > > > > > Cc: Neil Horman <nhorman@tuxdriver.com>
> > > > > > >
> > > > > > Sorry, but I'm not ok with this, because many of our DPDK PMDs have
> > > > > > functions that get exported which are meant to be called by
> > > > > > applications directly.  The
> > > > >
> > > > > OK. Just to update my knowledge, Should those API needs to go through
> > > > > ABI/API depreciation process?
> > > > >
> > > > Yes, they definately should, they are API's just as any other in the core DPDK
> > > > library.
> > > 
> > > OK
> > > 
> > > 
> > > > 
> > > > > Actually, I am concerned about the APIs, which is called between
> > > > > drviers not the application. For example,
> > > > > drivers/common/dpaax/rte_common_dpaax_version.map
> > > > >
> > > > > it is not interface to application rather it is for intra driver case.
> > > > > I think, I can change my logic to Skip the symbols which NOT starting with
> > > > rte_.
> > > > > Agree?
> > > > >
> > > > No, Thats just one case, and if those calls are between drivers, so be it, but
> > > > those still need to be stable, and we have other examples (like the bonding
> > > > or dummy driver), which have additional APIs that are explicitly meant to be
> > > > used by an application.
> > > 
> > > There is no disagreement on the API that exposed to application.
> > > I am concerned with internal driver APIs. For example, I am getting following warning
> > > 
> > > ERROR: symbol otx2_mbox_alloc_msg_rsp is added in the DPDK_19.05 section, but is expected to be added in the EXPERIMENTAL section of the version map
> > > 
> > Thats a warning about the fact that you added an API call in a versioned section
> > of a library instead of the Experimental section, thats part of our policy.  New
> > APIs need to go through the experimental tag first.
> > 
> > I understand what you are saying about driver only apis, and I mentioned that in
> > my other email farther down the thread.  The problem is that "driver only apis"
> > are currently just a conceptual thing for us to discuss.  They're still,
> > practially speaking, API's that any downstream user can access and become
> > dependent on, which we need to manage, either by keeping the API stable, so it
> > stays usable for all callers, or by developing a way to mark driver only API's
> > as such.  I proposed a method that you might use to do the latter in my other email.
> > 
> > > This API suppose to be called only a octeontx2 network driver from octeontx2 common driver
> > > i.e application should not expect any stability on intra driver functions or it does not meant to
> > > be used by application.
> > > 
> > Ok, but again, your assertion is that its driver to driver only, but in
> > practicaility, that assertion is irrelevant.  Those symbols are still exposed
> > for general use, and weather or not you say they aren't part of the ABI, the
> > fact of the matter is, there is no way to tell the difference from a linked
> > object standpoint.  Instead of hobbling the tool to just not scan anything, you
> > need to find a way to differentiate these symbols, so that you can enforce your
> > assertion that there are restrictions on where these APIs are called from.
> > 
> > Neil
> > 
> > > Thomas,
> > > Any thought on this?
> 
> As Neil said, we need to differentiate the internal APIs.
> We already have this issue in a number of places like EAL, or ethdev,
> and it was poorly addressed with some comments like "@internal".
> 
> Practically I don't care about stability of these internal functions,
> but I agree that it creates a mess in the tooling and confuse users.
> 
Agreed, If we can mark them in a way that can enforce no outside usage, then
there need not be any ABI compatibility guarantee

Neil

> 
>