Fwd: [ofa-general] limit on memory registration

[Rui Machado]

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---------- Forwarded message ----------
From: Rui Machado <ruimario at gmail.com>
Date: 2008/8/11
Subject: Re: [ofa-general] limit on memory registration
To: Dotan Barak <dotanba at gmail.com>


2008/8/6 Dotan Barak <dotanba at gmail.com>:
> Rui Machado wrote:
>>
>> Hi all,
>>
>> is there any limitation on the size that can be registered
>> (ibv_reg_mr) for communication?
>> I seem to be limited to 16GB (on 32GB 64bit x86 machine).
>> Is this normal? Can someone tell me why and/or if there is a workaround?
>>
>
> In the device attributes there is an attribute called max_mr_size which
> indicate the maximum block size
> that can be registered for a device.
>
> There is one more limitation which is a device specific for the translation
> table virtual <-->physical
> You can check the low level driver of the HW that you are using in order to
> increase the size
> of this table.
>
> which HW do you use?
>

I  am now working with another hw. Mellanox ConnectX HCA
But I still have the limitation on the amount of memory to register.
I would really like to understand what's going on here and why does it
fail. And I also the need to fix it :-/ (case it's possible)
Any help is much appreciated.

Cheers