From owner-svn-src-stable@freebsd.org Mon Jul 8 19:27:39 2019 Return-Path: Delivered-To: svn-src-stable@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id D995915E7BB8; Mon, 8 Jul 2019 19:27:39 +0000 (UTC) (envelope-from hps@selasky.org) Received: from mail.turbocat.net (turbocat.net [IPv6:2a01:4f8:c17:6c4b::2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) server-signature RSA-PSS (4096 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 78C8287A7C; Mon, 8 Jul 2019 19:27:39 +0000 (UTC) (envelope-from hps@selasky.org) Received: from hps2016.home.selasky.org (unknown [62.141.129.235]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits)) (No client certificate requested) by mail.turbocat.net (Postfix) with ESMTPSA id 849132603F7; Mon, 8 Jul 2019 21:27:36 +0200 (CEST) Subject: Re: svn commit: r349763 - in stable/12/sys: kern sys To: John Baldwin , src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-12@freebsd.org References: <201907051226.x65CQUev056366@repo.freebsd.org> <97b7657c-53b9-f3d2-f31a-5e56343da71d@FreeBSD.org> <1bd91e31-920c-8857-f900-f66fb99f95d3@selasky.org> <3f85335c-635e-c37f-f887-39c1c3e7858d@FreeBSD.org> From: Hans Petter Selasky Message-ID: Date: Mon, 8 Jul 2019 21:26:58 +0200 User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <3f85335c-635e-c37f-f887-39c1c3e7858d@FreeBSD.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 78C8287A7C X-Spamd-Bar: ------ Authentication-Results: mx1.freebsd.org X-Spamd-Result: default: False [-6.97 / 15.00]; NEURAL_HAM_MEDIUM(-1.00)[-1.000,0]; NEURAL_HAM_LONG(-1.00)[-1.000,0]; REPLY(-4.00)[]; NEURAL_HAM_SHORT(-0.97)[-0.974,0] X-BeenThere: svn-src-stable@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: SVN commit messages for all the -stable branches of the src tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 08 Jul 2019 19:27:40 -0000 On 2019-07-08 19:09, John Baldwin wrote: > On 7/5/19 3:02 PM, Hans Petter Selasky wrote: >> On 2019-07-05 17:49, John Baldwin wrote: >>> How does this not break the module KBI? You've removed epoch_*_KBI symbols used >>> by existing modules, and you appear to have changed the size of the >>> 'struct epoch_tracker' object that existing modules allocate on the stack and >>> pass to functions in the kernel. Bumping __FreeBSD_version is not sufficient >>> cover to break the KBI of widely used interfaces in stable (while we don't >>> enforce KBI for all parts of the kernel, locking primitives is one of the things >>> we can't break). >> >> Hi John, >> >> I'm aware there is a KPI breakage, but there is no API or functionality >> breakage. >> >> The epoch(9) API is a very new API and I don't expect it to be widely >> used for binary only modules. Do you have any examples otherwise? >> >> man 9 epoch >> >> clearly states: >> >> NOTES >> The epoch kernel programming interface is under development and is >> subject to change. >> >> epoch(9) is currently mostly used inside the kernel which has to be >> re-compiled. >> >> If you think it is really important that epoch(9) will stay KBI >> compliant I'll do the work to fix that. > > Despite the NOTES claim, given its wide use it is effectively part of the KBI > just as much as 'struct mtx'. We also do not limit KBI to just binary-only > modules. It makes it much harder to test for one thing. You should be able > to take a 12.0 if_tap.ko and load it and use it with a stable/12 GENERIC > kernel for example. I think you've broken that. > Maybe I'm missing something, but won't this be blocked by the incremented __FreeBSD_version value in 12-stable vs 12.0 ??? --HPS