Date: Tue, 27 Feb 2018 00:43:11 +0200 From: Konstantin Belousov <kib@freebsd.org> To: Navdeep Parhar <np@FreeBSD.org> Cc: Meny Yossefi <menyy@mellanox.com>, "'freebsd-infiniband@freebsd.org'" <freebsd-infiniband@freebsd.org>, "'FreeBSD-stable@FreeBSD.org'" <FreeBSD-stable@FreeBSD.org>, freebsd-arch <freebsd-arch@freebsd.org>, freebsd-drivers <freebsd-drivers@mellanox.com> Subject: Re: [HEADS UP] - OFED/RDMA stack update Message-ID: <20180226224311.GT94212@kib.kiev.ua> In-Reply-To: <1519683699.47932.5.camel@FreeBSD.org> References: <VI1PR0501MB2863AC74A6345BD07068DA34C3C10@VI1PR0501MB2863.eurprd05.prod.outlook.com> <1519683699.47932.5.camel@FreeBSD.org>
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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..
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