From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Steve Wise" 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> 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> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <010c01d0be76$dbb4c520$931e4f60$@opengridcomputing.com> Content-Language: en-us Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: 'Jason Gunthorpe' Cc: 'Christoph Hellwig' , 'Sagi Grimberg' , 'Steve Wise' , 'Tom Talpey' , 'Doug Ledford' , sagig-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org, ogerlitz-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org, roid-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org, linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, eli-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org, target-devel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-nfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, trond.myklebust-7I+n7zu2hftEKMMhf/gKZA@public.gmane.org, bfields-uC3wQj2KruNg9hUCZPvPmw@public.gmane.org, 'Oren Duer' List-Id: linux-rdma@vger.kernel.org > -----Original Message----- > From: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org [mailto:linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.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-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org; ogerlitz-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org; > roid-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org; linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org; eli-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org; target-devel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org; linux-nfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org; > trond.myklebust-7I+n7zu2hftEKMMhf/gKZA@public.gmane.org; bfields-uC3wQj2KruNg9hUCZPvPmw@public.gmane.org; 'Oren Duer' > Subject: RE: [PATCH V3 1/5] RDMA/core: Transport-independent access flags > > > > > -----Original Message----- > > From: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org [mailto:linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.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-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org; ogerlitz-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org; > > roid-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org; linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org; eli-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org; target-devel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org; linux-nfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org; > > trond.myklebust-7I+n7zu2hftEKMMhf/gKZA@public.gmane.org; bfields-uC3wQj2KruNg9hUCZPvPmw@public.gmane.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? -- 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