From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jason Gunthorpe Subject: Re: kernel memory registration Date: Tue, 14 Jul 2015 11:24:29 -0600 Message-ID: <20150714172429.GA24403@obsidianresearch.com> References: <559CD174.4040901@dev.mellanox.co.il> <20150708190842.GB11740@obsidianresearch.com> <559D983D.6000804@talpey.com> <20150708233604.GA20765@obsidianresearch.com> <559E54AB.2010905@dev.mellanox.co.il> <20150709170142.GA21921@obsidianresearch.com> <559F8881.7070308@dev.mellanox.co.il> <20150711103153.GC14741@infradead.org> <20150713164652.GC23832@obsidianresearch.com> <55A4C73A.7080001@dev.mellanox.co.il> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <55A4C73A.7080001-LDSdmyG8hGV8YrgS2mwiifqBs+8SCbDb@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Sagi Grimberg Cc: 'Christoph Hellwig' , Tom Talpey , Steve Wise , dledford-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, 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, Oren Duer List-Id: linux-rdma@vger.kernel.org On Tue, Jul 14, 2015 at 11:24:26AM +0300, Sagi Grimberg wrote: > > > > >>Having a few schemes availabe in the core code that the driver can chose > >>from seems like a much more sensible option. > > > >I think that makes sense, but several of the schemes we are working > >with are effectively single-vendor schemes. Indirect MR and DIX are > >good examples of things that only one vendor implements, and are not > >standardized. > > > >In those cases it is hard to argue the core should provide support for > >them. > > I'm sorry but I disagree with the statement above. T10-DIF/DIX is a > standard and *not* a vendor specific feature. Other storage protocols > (FC, SAS, NVME) fully support it. So yes, the core *needs* to support it. Sorry, I ment the exact details of how DIX is exposed through verbs is only implemented by one vendor (eg IB_WR_REG_SIG_MR). The core absolutely should provide an API for this, I'm not convinced it should be at the MR level though.... > Moreover, the core stack poses memory alignment limitations for > registration. The RDMA stack should allow an interface that can resolve > these limitations if the device is capable of handling them. I'd say > this is something all vendors should look at. Sure would be nice.. 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