[ewg] RE: [ofa-general] OFED Jan 14 meeting summary on RC2readiness

[Gleb Natapov]

On Wed, Jan 16, 2008 at 09:35:39PM -0800, Roland Dreier wrote:
>  > Roland, you said that XRC API is ugly, are you going to push it upstream
>  > in its present form?
> 
> That's a good question.  Since there is no 'present form' for XRC as
> far as I can tell, it's hard to make a definitive answer.  Certainly I
There is a proposed API. Jack is working on an implementation. API is
not pretty at all, but it seems that with the way XRC is implemented in HW
it is hard to think about better one. It is very important to decide if
API is good enough for kernel proper before releasing OFED1.3. After
that the damage will be done.

> haven't made up my mind in advance one way or another.  In addition to
> seeing how the code ends up, I think the other big piece of the puzzle
> is to hear from the Open MPI team and other consumers of the API and
> find out how big the benefit is.
> 
Well, I can't speak for everyone, but in my opinion if someone wants to run
MPI job so huge that XRC absolutely has to be used to be able to actually
finish it then he should seriously rethink his application design. This is
only my opinion of cause, I am sure if you'll ask Mellanox they will
tell you that XRC is the best thing that happened to networking since
invention of Infiniband :). XRC can be used not just for scalability BTW.
It can be used as a way to post differently sized buffers to the same QP
and this is very useful, but for this kind of usage the most ugly parts of
the API are not needed. I will be glad to hear other people's opinions too
(I know Mellanox one).

--
			Gleb.