[Numpy-discussion] Openmp support (was numpy's future (1.1 and beyond): which direction(s) ?)

David Cournapeau david@ar.media.kyoto-u.ac...
Sat Mar 22 04:40:55 CDT 2008


Matthieu Brucher wrote:
> Hi,
>
> It seems complicated to add OpenMP in the code, I don't think many 
> people have the knowlegde to do this, not mentioning the fact that 
> there are a lotof Python calls in the different functions.

Yes, this makes potential optimizations harder, at least for someone 
like me who do not know well about numpy internals. That's still 
something I have not thought a lot about, but that's an example of why I 
like the idea of splitting numpy C code in core C / wrappers: you would 
only use open MP in the core C library, and everything would be 
transparent at higher levels (if I understand correctly how openMP 
works, which may very well not be true :) ).

OpenMP, sse, etc... those are different views of the same underlying 
"problem", in this context. But I do not know enough about numpy 
internals yet (in particular, how the number protocol works, and the 
relationship with the ufunc machinery) to know if it is feasible in a 
reasonable number of hours, or even if it is feasible at all :)

> The multicore Matlab does seems for more related to the underlying 
> libraries than to something they did.
>

Yes, that's why I put the matlab link: actually, most of the parallel 
thing it does is related to the mkl and co. That's something which is 
much easier to handle, and possible right now if I understand right ?

cheers,

David


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