From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jason Gunthorpe Subject: Re: [RFC ABI V1 4/8] RDMA/core: Add support for custom types Date: Wed, 20 Jul 2016 11:49:05 -0600 Message-ID: <20160720174905.GL21460@obsidianresearch.com> References: <20160712192345.GC8206@obsidianresearch.com> <081a02c0-0650-d0c2-494c-19a64b83cbc1@mellanox.com> <20160713163924.GA19657@obsidianresearch.com> <0959d391-75fb-75e8-ef2e-9d8c06b1b96f@mellanox.com> <20160713172116.GC19657@obsidianresearch.com> <5fdae959-5ab2-ee17-e36e-3642ddd3e6ce@mellanox.com> <20160714164121.GA2046@obsidianresearch.com> <20160719203609.GD16042@obsidianresearch.com> <9727f6e6-47fd-fb0a-537f-6264e8d742a9@mellanox.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <9727f6e6-47fd-fb0a-537f-6264e8d742a9-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Matan Barak Cc: linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Doug Ledford , Sean Hefty , Tal Alon , Liran Liss , Haggai Eran , Majd Dibbiny , Christoph Lameter , Leon Romanovsky List-Id: linux-rdma@vger.kernel.org On Wed, Jul 20, 2016 at 11:01:18AM +0300, Matan Barak wrote: > But how would you know if rdma-cm is loaded and available? Don't we want to > have a decent query interface rather than iterating through sysfs? > I agree that it could be lower priority than the rest. 1) 'loaded available' I think you will agree we have a fairly bad user experience when it comes to autoloading modules. If we have one fd, and the core of that FD is part of the ib_core module that is pulled in on driver load then the a request for an API segment (eg uverbs, rdma_cm) can now actually trigger a module load, just like net does for PF's. So we actually get to a better, saner, place. 2) Yes, an in-band query interface makes much more sense than schlepping around sysfs. That could be done in the ioctl, or maybe via netlink, but as you say, lower priority. > I meant moving to /dev/rdma_uapi, but when you fopen the device and get a > fd, you could either have fd->NULL or fd->single_rdma_dev mapping. > It's a little bit simpler, however, not that much from just doing 1:N > mapping. A major point of the unified interface is to sanely support rdma_cm when working with multiple devices, so I'd expect 1:N is the only reasonable option for that interface.. Jason -- 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