From mboxrd@z Thu Jan 1 00:00:00 1970 From: Roland Dreier Subject: Re: Ummunotify: progress at last! Date: Tue, 23 Mar 2010 22:55:08 -0700 Message-ID: References: <1CDB2AA4-A8DF-4169-943E-4EA190814596@cisco.com> <20100323165920.GH29129@obsidianresearch.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: In-Reply-To: <20100323165920.GH29129-ePGOBjL8dl3ta4EC/59zMFaTQe2KTcn/@public.gmane.org> (Jason Gunthorpe's message of "Tue, 23 Mar 2010 10:59:20 -0600") Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Jason Gunthorpe Cc: Jeff Squyres , Linux RDMA List , Brad Benton List-Id: linux-rdma@vger.kernel.org > I would prefer to do this by adding a new verbs call that returns a fd > directly. Ie use ib_uverbs_alloc_event_file and act like > ibv_create_comp_channel. > > The main reason for the new FD is so it can be polled on.. Agree, we don't want a new device node I don't think -- too hard to associate an fd you get from a separate open() with a uverbs context. > You can also avoid the mmap scheme by doing what perf events does, > pass in a pointer from userspace and have the kernel pin that page it > is on. I wonder, is that a win? I guess you don't even have to pin it, just do copy_to_user() to update the counter, but mmap doesn't seem so bad. I'll have to look at the perf code. -- Roland Dreier For corporate legal information go to: http://www.cisco.com/web/about/doing_business/legal/cri/index.html -- 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