From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Steve Wise" Subject: RE: [PATCH 0/3] RDMA/core: iWARP Port Mapper Overview Date: Mon, 9 Jun 2014 13:12:50 -0500 Message-ID: <004501cf840e$6cf0c240$46d246c0$@opengridcomputing.com> References: <20140326220718.GA8784@TENIKOLO-MOBL1> <20140609165105.GB1816@obsidianresearch.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20140609165105.GB1816-ePGOBjL8dl3ta4EC/59zMFaTQe2KTcn/@public.gmane.org> Content-Language: en-us Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: 'Jason Gunthorpe' , 'Or Gerlitz' Cc: 'Tatyana Nikolova' , 'Roland Dreier' , "'Lacombe, John S'" , 'Sean Hefty' , 'linux-rdma' List-Id: linux-rdma@vger.kernel.org > -----Original Message----- > From: Jason Gunthorpe [mailto:jgunthorpe-ePGOBjL8dl3ta4EC/59zMFaTQe2KTcn/@public.gmane.org] > Sent: Monday, June 09, 2014 11:51 AM > To: Or Gerlitz > Cc: Tatyana Nikolova; Steve Wise; Roland Dreier; Lacombe, John S; Sean Hefty; linux-rdma > Subject: Re: [PATCH 0/3] RDMA/core: iWARP Port Mapper Overview > > On Sun, Jun 08, 2014 at 10:34:30PM +0300, Or Gerlitz wrote: > > What it does is the following: > > > > 1. kernel rdma driver tells a user space daemon they want to reserve > > (claim) the combination of IP address X and TCP port Y for the sake of > > RDMA connections > > > > 2. user space daemon opens a socket and binds to X:Y > > > > Specifically, down the road, more use cases, not only the current > > iWARP case may pop up. > > This really seems horrible, using user space to circumvent the kernel > stack because kernel maintainers don't want this kind of integration > is not going to make people very happy. > > IIRC the patch set that tried to do this directly in the kernel was > NAK'd, adding a userspace round trip doesn't really change anything. > The patch set you refer to tried to _unify_ the port space and was rejected. The only other alternative is to pick ephemeral ports and maintain a mapping for RDMA services. > The message from netdev has, IMHO, always been pretty clear - offload > can live in it's own little side world but cannot appear to the user > to be integrated to the main stack (because it isn't). That is what this design does... Steve. -- 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