From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jason Gunthorpe Subject: Re: QoS in local SA entity Date: Mon, 9 Nov 2009 01:08:12 -0700 Message-ID: <20091109080812.GX1966@obsidianresearch.com> References: <4AF2C00A.4040808@voltaire.com> <9BF1CEFA7F6F44F5B5641065C4914EB5@amr.corp.intel.com> <4AF66473.2050303@voltaire.com> <20091109005607.GV1966@obsidianresearch.com> <4AF7C85F.5000604@voltaire.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <4AF7C85F.5000604-smomgflXvOZWk0Htik3J/w@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Or Gerlitz Cc: Sean Hefty , linux-rdma List-Id: linux-rdma@vger.kernel.org On Mon, Nov 09, 2009 at 09:44:31AM +0200, Or Gerlitz wrote: > No rdma_resolve_addr2 is needed the one that exists now has > source addresses specified, I don't see that extra info is needed for > AF_INET that was resolved with rdma_getaddrinfo is this AF_IB specific? The extra info in rdma_resolve_addr2 carries the IB specific path information from the rdma_getaddrinfo module to the kernel for the address pair. Then entire purpose of AF_IB is to let user space tell the kernel it does not want a kernel side ND and PR query, instead user space will provide all the information. Think of it this way, ACM takes over the entire process of what AF_INET does in the kernel. AF_INET talks directly to the IB CM module in the kernel. Thus, it also makes sense that ACM would need to talk to IB CM directly as well. AF_IB is that direct connection. > I don't see why the app should bother on calling rdma_getaddrinfo, it > can be done by librdmacm with rdma_getaddrinfo having multiple modules > as you suggested. I am in favor of the approach suggested by Sean of > librdmacm either doing its native flow or under environment variable > doing an alternative flow, where your suggestion not to have the 2nd > flow being tightly coupled with ACM, e.g through using get_addrinfo > abstraction and friends makes sense (yes!) I don't entirely understand this paragraph, but the point of a string based rdma_getaddrinfo is exactly the same point as for IP - strings may have different meaning and may encode richer information than a simple sock addr (eg normal getaddrinfo can determine AF_INET, AF_INET6, and AF_UNIX depending on the form of the string). For instance it might make sense to trigger/disable the ACM method with a special string based indicator. 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