[Cython] [Re] OpenMP thread private variable not recognized (bug report + discussion)

[Sturla Molden]

"Leon Bottou" <leon at bottou.org> wrote:

> I am making heavy uses of OpenBlas which also uses OpenMP.
> Using the same queue manager prevents lots of CPU provisioning problem.
> Using multiple queue managers in the same code does not work as well because
> they are not aware of what the other one is doing.

Normally OpenBLAS is built without OpenMP. Also, OpenMP is not fork safe
(cf. multiprocessing) but OpenBLAS' own threadpool is. So it is recommended
to build OpenBLAS without OpenMP dependency.

That is: If you build OpenBLAS with OpenMP, numpy.dot will hang if used
together with multiprocessing.


Sturla