From mboxrd@z Thu Jan 1 00:00:00 1970 From: Or Gerlitz Subject: Re: [PATCH 1/2] libibverbs: Allow 3rd party extensions to verb routines Date: Sun, 1 Jan 2012 07:13:32 +0200 Message-ID: <4EFFEB7C.6090202@mellanox.com> References: <1828884A29C6694DAF28B7E6B8A8237302123C@ORSMSX101.amr.corp.intel.com> <201108011508.06521.jackm@dev.mellanox.co.il> <20110802053824.GA23512@obsidianresearch.com> <201108021053.05311.jackm@dev.mellanox.co.il> <1828884A29C6694DAF28B7E6B8A82373136F935C@ORSMSX101.amr.corp.intel.com> <4EFC8A85.4020803@mellanox.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4EFC8A85.4020803-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: "Hefty, Sean" Cc: Jack Morgenstein , Jason Gunthorpe , Roland Dreier , "linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Liran Liss , Oren Duer List-Id: linux-rdma@vger.kernel.org > >> or call an existing function with some new enum value > > 5. what happens if we just want to enhance an -- existing -- function > - suppose we want to enhance ibv_post_send / ibv_poll_cq to support > features like LSO, checksum offload, masked atomic operations, fast > memory remote invalidate, etc so we add IBV_WR_NEW_FEATURE / > IB_WC_NEW_FEATURE enum values, this step is simple, again if we go the > way of the applicayion ensuring through dependencies that they are > loaded against libibverbs that supports IB_{WR,WC}_NEW_FEATURE. Another element to take into account / use here, is the device capabilities, in the kernel RDMA stack this is the way to go for supporting extended features - those who are not common to all devices, e.g the way ipoib queries the device and concludes if checksum/lso offloads can be exposed to the network stack, or the rpc/rdma layer decides what memory management model to use for rdma conditioned if memory extensions etc are supported. But the kernel is one piece, so if a cap is defined and there's a driver down there advertizing it, all is in place software wise, where in user space, there are some more layers to address, as this thread attempts to do. Or. -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html