From owner-freebsd-arch@freebsd.org Mon Feb 26 22:43:27 2018 Return-Path: Delivered-To: freebsd-arch@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 A0D82F29C9D; Mon, 26 Feb 2018 22:43:27 +0000 (UTC) (envelope-from kib@freebsd.org) Received: from kib.kiev.ua (kib.kiev.ua [IPv6:2001:470:d5e7:1::1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id F18DB7086C; Mon, 26 Feb 2018 22:43:26 +0000 (UTC) (envelope-from kib@freebsd.org) Received: from tom.home (kib@localhost [127.0.0.1]) by kib.kiev.ua (8.15.2/8.15.2) with ESMTPS id w1QMhBXt073562 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Tue, 27 Feb 2018 00:43:14 +0200 (EET) (envelope-from kib@freebsd.org) DKIM-Filter: OpenDKIM Filter v2.10.3 kib.kiev.ua w1QMhBXt073562 Received: (from kostik@localhost) by tom.home (8.15.2/8.15.2/Submit) id w1QMhBvk073561; Tue, 27 Feb 2018 00:43:11 +0200 (EET) (envelope-from kib@freebsd.org) X-Authentication-Warning: tom.home: kostik set sender to kib@freebsd.org using -f Date: Tue, 27 Feb 2018 00:43:11 +0200 From: Konstantin Belousov To: Navdeep Parhar Cc: Meny Yossefi , "'freebsd-infiniband@freebsd.org'" , "'FreeBSD-stable@FreeBSD.org'" , freebsd-arch , freebsd-drivers Subject: Re: [HEADS UP] - OFED/RDMA stack update Message-ID: <20180226224311.GT94212@kib.kiev.ua> References: <1519683699.47932.5.camel@FreeBSD.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1519683699.47932.5.camel@FreeBSD.org> User-Agent: Mutt/1.9.3 (2018-01-21) X-Spam-Status: No, score=-2.9 required=5.0 tests=ALL_TRUSTED,BAYES_00 autolearn=ham autolearn_force=no version=3.4.1 X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on tom.home X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.25 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 26 Feb 2018 22:43:27 -0000 On Mon, Feb 26, 2018 at 02:21:39PM -0800, Navdeep Parhar wrote: > +freebsd-arch@ > > Hi Meny, > > Can you please post the KPI/KBI analysis that you generated to some > public location and provide a link here? A straight MFC would be a > major break of KPI/KBI in -STABLE and the options we're looking at are: I put the report at https://kib.kiev.ua/kib/ibcore_11_to_11_merged_compat_report.html > > a) Ignore the breakage and let downstream consumers deal with the > fallout. This obviously isn't ideal in a -STABLE branch. > > b) Provide compat shims to at least preserve the KPI. One challenge is > that the changes include functions with the same name but different > signature/behavior. See, for example, ib_create_cq in Meny's list once > he publishes it. Project did handled similar issues already. One of the approaches is to renname the ib_create_cq with the new signature to ib_create_cq_n12 and check for (e.g.) _WANT_NEW_OFED symbol and to select one or another: #ifdef _WANT_NEW_OFED #define ib_create_cq(new args there) ib_create_cq_n21(new args there) #else #define ib_create_cq (ib_create_cq) #endif Then ULP that wants new KPI defines _WANT_NEW_OFED. > > c) Have two versions of the OFED interfaces in 11-STABLE and not break > existing downstream consumers at all. It is possible to make them loadable simultaneously as modules, but it is quite confusing to users, because Mellanox clearly wants mlx5_ib and mlx4_ib to work only with new OFED, while cxgbe would use old OFED ? Also, either we would need to mess with the ibcore.ko module name, or with version. I am not sure that our module handling is robust enough to make the version trick possible. > > I've reached out to users that I know of and know will be affected. > If you use OFED and FreeBSD 11 this would be a good time to weigh > in with your thoughts, ideas, concerns etc..