From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: Re: [PATCH 1/5] IB/core: Introduce Fast Indirect Memory Registration verbs API Date: Tue, 30 Jun 2015 05:10:02 -0700 Message-ID: <20150630121002.GA24169@infradead.org> References: <1433769339-949-1-git-send-email-sagig@mellanox.com> <1433769339-949-2-git-send-email-sagig@mellanox.com> <1828884A29C6694DAF28B7E6B8A82373A8FE5C7C@ORSMSX109.amr.corp.intel.com> <559281B4.6010807@dev.mellanox.co.il> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <559281B4.6010807-LDSdmyG8hGV8YrgS2mwiifqBs+8SCbDb@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Sagi Grimberg Cc: "Hefty, Sean" , Sagi Grimberg , Doug Ledford , "linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Or Gerlitz , Eli Cohen , Oren Duer , Boaz Harrosh , Liran Liss List-Id: linux-rdma@vger.kernel.org On Tue, Jun 30, 2015 at 02:47:00PM +0300, Sagi Grimberg wrote: > Kernel 4.1 introduced the new pmem driver for byte addressable storage > (https://lwn.net/Articles/640115/). It won't be long before we see HA > models where secondary persistent memory devices will sit across an > RDMA fabric. (http://www.snia.org/sites/default/files/DougVoigt_RDMA_Requirements_for_HA.pdf) And what does this bullshitting slide have to do with our memory models? In it's current form the pmem driver can't even be used as a (R)DMA target, so it's totally irrelevant for now. Let's get a proper in-kernel interface for generic memory registrations in place as a first step. le this will be a significant amount of work it'll help greatly with moving nasty implementation details out of the drivers. Adding additional registrations methods will be easy behind the back of a proper abstraction. > Do we want to live with this limitation forever? I don't think anyone has refused additional support. Just the way how it's done in your patches is a giant nightmare. The whole RDMA stack needs a healthy dose of software engineering instead of blindly following a working group of a marketing organisation. -- 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