Return-Path: Received: from smtp.opengridcomputing.com ([72.48.136.20]:36383 "EHLO smtp.opengridcomputing.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752132AbbGNVBB (ORCPT ); Tue, 14 Jul 2015 17:01:01 -0400 From: "Steve Wise" To: "'Jason Gunthorpe'" Cc: "'Christoph Hellwig'" , "'Sagi Grimberg'" , "'Steve Wise'" , "'Tom Talpey'" , "'Doug Ledford'" , , , , , , , , , , "'Oren Duer'" References: <20150709000337.GE16812@obsidianresearch.com> <559EF332.7060103@redhat.com> <20150709225306.GA30741@obsidianresearch.com> <559FC710.1050307@talpey.com> <20150710161108.GA19042@obsidianresearch.com> <55A24571.60902@dev.mellanox.co.il> <00e201d0be6a$e49bc910$add35b30$@opengridcomputing.com> <20150714194512.GA25887@infradead.org> <00f901d0be6f$70c96b00$525c4100$@opengridcomputing.com> <20150714204145.GC26927@obsidianresearch.com> <010c01d0be76$dbb4c520$931e4f60$@opengridcomputing.com> In-Reply-To: <010c01d0be76$dbb4c520$931e4f60$@opengridcomputing.com> Subject: RE: [PATCH V3 1/5] RDMA/core: Transport-independent access flags Date: Tue, 14 Jul 2015 16:01:04 -0500 Message-ID: <011001d0be78$32412ef0$96c38cd0$@opengridcomputing.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Sender: linux-nfs-owner@vger.kernel.org List-ID: > -----Original Message----- > From: linux-rdma-owner@vger.kernel.org [mailto:linux-rdma-owner@vger.kernel.org] On Behalf Of Steve Wise > Sent: Tuesday, July 14, 2015 3:51 PM > To: 'Jason Gunthorpe' > Cc: 'Christoph Hellwig'; 'Sagi Grimberg'; 'Steve Wise'; 'Tom Talpey'; 'Doug Ledford'; sagig@mellanox.com; ogerlitz@mellanox.com; > roid@mellanox.com; linux-rdma@vger.kernel.org; eli@mellanox.com; target-devel@vger.kernel.org; linux-nfs@vger.kernel.org; > trond.myklebust@primarydata.com; bfields@fieldses.org; 'Oren Duer' > Subject: RE: [PATCH V3 1/5] RDMA/core: Transport-independent access flags > > > > > -----Original Message----- > > From: linux-rdma-owner@vger.kernel.org [mailto:linux-rdma-owner@vger.kernel.org] On Behalf Of Jason Gunthorpe > > Sent: Tuesday, July 14, 2015 3:42 PM > > To: Steve Wise > > Cc: 'Christoph Hellwig'; 'Sagi Grimberg'; 'Steve Wise'; 'Tom Talpey'; 'Doug Ledford'; sagig@mellanox.com; ogerlitz@mellanox.com; > > roid@mellanox.com; linux-rdma@vger.kernel.org; eli@mellanox.com; target-devel@vger.kernel.org; linux-nfs@vger.kernel.org; > > trond.myklebust@primarydata.com; bfields@fieldses.org; 'Oren Duer' > > Subject: Re: [PATCH V3 1/5] RDMA/core: Transport-independent access flags > > > > On Tue, Jul 14, 2015 at 02:58:23PM -0500, Steve Wise wrote: > > > The local_dma_lkey can be used in any rdma sge that requires an > > > lkey. > > > > No, this is where iWarp doesn't follow the generic API - a local dma > > lkey cannot be used with iWarp's RDMA_READ WR lkey. In effect RDMA > > READ requires an *rkey* (confusingly stuck into the lkey slot) for > > iWarp. (Right?) > > > > Right, a local_dma_lkey is not an rkey, and iwarp requires the rkey for the read destination MR. Further that rkey needs > REMOTE_WRITE. > BTW: What use is an IB rkey with no REMOTE_ flags set? Can it be used somehow differently than the associated lkey?