From owner-svn-src-stable-12@freebsd.org Fri Jul 5 22:03:12 2019 Return-Path: Delivered-To: svn-src-stable-12@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 53E7215D5F9B; Fri, 5 Jul 2019 22:03:12 +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 E32178BEFB; Fri, 5 Jul 2019 22:03:11 +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 210442604A5; Sat, 6 Jul 2019 00:03:08 +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> From: Hans Petter Selasky Message-ID: <1bd91e31-920c-8857-f900-f66fb99f95d3@selasky.org> Date: Sat, 6 Jul 2019 00:02:31 +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: <97b7657c-53b9-f3d2-f31a-5e56343da71d@FreeBSD.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: E32178BEFB X-Spamd-Bar: ------ Authentication-Results: mx1.freebsd.org X-Spamd-Result: default: False [-6.94 / 15.00]; REPLY(-4.00)[]; NEURAL_HAM_SHORT(-0.94)[-0.942,0]; NEURAL_HAM_MEDIUM(-1.00)[-1.000,0]; NEURAL_HAM_LONG(-1.00)[-1.000,0] X-BeenThere: svn-src-stable-12@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: SVN commit messages for only the 12-stable src tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 05 Jul 2019 22:03:12 -0000 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. --HPS