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Subject: Re: [PATCH V3 1/5] RDMA/core: Transport-independent access flags
To: Tom Talpey <tom@talpey.com>,
        Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
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From: Sagi Grimberg <sagig@dev.mellanox.co.il>
Message-ID: <55A50CEA.1090504@dev.mellanox.co.il>
Date: Tue, 14 Jul 2015 16:21:46 +0300
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On 7/14/2015 3:24 PM, Tom Talpey wrote:
> 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.
>

Exactly. This is why I'd prefer not to make an effort to have a unified
API that maintains any form of (confusing) fallback policy.