From mboxrd@z Thu Jan  1 00:00:00 1970
From: Sagi Grimberg <sagi-NQWnxTmZq1alnMjI0IkVqw@public.gmane.org>
Subject: Re: RDMA Read: Local protection error
Date: Sun, 29 May 2016 11:13:50 +0300
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>> Really? It's used all over the stack...
>>
>> So the suggestion is to restrict the allocation does not
>> cross the page boundary (which can easily be done with making
>> MLX4_MR_PAGES_ALIGN be PAGE_SIZE or larger than PAGE_SIZE/2)?
>
> We could simply switch to alloc_pages, e.g. something like the patch below:

Patch below? :)

> But I have to admit I really like the coherent dma mapping version,
> for all sane architectures that works much better, although it sucks
> for some architetures where dma coherent mappings cause a bit of
> overhead.

But this is specific to mlx4 which supports up 511 pages per MR, mlx5
will need a coherent allocation anyways right (it supports up to 64K
pages per MR)?
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