Message-ID: <55A4FF93.4090406@talpey.com>
Date: Tue, 14 Jul 2015 08:24:51 -0400
From: Tom Talpey <tom@talpey.com>
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To: Sagi Grimberg <sagig@dev.mellanox.co.il>,
        Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
CC: Christoph Hellwig <hch@infradead.org>,
        Chuck Lever <chuck.lever@oracle.com>,
        "Hefty, Sean" <sean.hefty@intel.com>,
        Steve Wise <swise@opengridcomputing.com>,
        "dledford@redhat.com" <dledford@redhat.com>,
        "sagig@mellanox.com" <sagig@mellanox.com>,
        "ogerlitz@mellanox.com" <ogerlitz@mellanox.com>,
        "roid@mellanox.com" <roid@mellanox.com>,
        "linux-rdma@vger.kernel.org" <linux-rdma@vger.kernel.org>,
        "eli@mellanox.com" <eli@mellanox.com>,
        "target-devel@vger.kernel.org" <target-devel@vger.kernel.org>,
        Linux NFS Mailing List <linux-nfs@vger.kernel.org>,
        Trond Myklebust <trond.myklebust@primarydata.com>,
        "J. Bruce Fields" <bfields@fieldses.org>,
        Oren Duer <oren@mellanox.com>
Subject: Re: [PATCH V3 1/5] RDMA/core: Transport-independent access flags
References: <559CD174.4040901@dev.mellanox.co.il> <20150708081320.GB24203@infradead.org> <559CF5E8.6080000@dev.mellanox.co.il> <20150708102035.GA28421@infradead.org> <559D0498.9050809@dev.mellanox.co.il> <1828884A29C6694DAF28B7E6B8A82373A8FFD4C0@ORSMSX109.amr.corp.intel.com> <559E34F8.4080507@dev.mellanox.co.il> <2189DB0A-DD00-4818-AC17-020FCE42D39B@oracle.com> <20150710193409.GA9815@infradead.org> <55A21BF4.7090601@dev.mellanox.co.il> <20150713165007.GD23832@obsidianresearch.com> <55A4C2FA.9060707@dev.mellanox.co.il>
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On 7/14/2015 4:06 AM, Sagi Grimberg wrote:
> All protocols cares about transferring data and sending messages, so
> it's not a good enough reason for a poor registration method choice.
> This just emphasizes why we need to converge to a single method.

In my opinion, we already have it.

For local registrations, ib_reg_phys_mr()/ib_get_dma_mr(). These are not
quite equivalent, btw.

For remote registrations, ib_post_send(FRMR).

Unfortunately, there exist ancient adapters in-tree that don't support
FRMR, and some ULPs have attempted to work on them. That's why the
situation is confusing.