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

Roland Dreier rdreier at cisco.com
Thu Jan 17 17:25:14 PST 2008


 > 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.

But where do you think the crossover is where XRC starts to help MPI?
In other words do I need a 10000 process job on 32-core systems for it
to matter, or is there a significant advantage for running a 2048
process job on 256 8-core systems?

 > 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).

I guess you mean just implement XRC without allowing multiple
processes to share an XRC domain?  That actually seems like a sensible
thing to implement as well...

 - R.



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