[Numpy-discussion] MKL and OpenBLAS

Julian Taylor jtaylor.debian at googlemail.com
Sun Jan 26 17:13:17 EST 2014

On 26.01.2014 22:33, Sturla Molden wrote:
> Julian Taylor <jtaylor.debian at googlemail.com> wrote:
>> if this issue disqualifies accelerate, it also disqualifies openblas as
>> a default. openblas has the same issue, we stuck a big fat warning into
>> the docs (site.cfg) for this now as people keep running into it.
> What? Last time I checked, OpenBLAS (and GotoBLAS2) used OpenMP, not the
> GCD on Mac. Since OpenMP compiles to pthreads, it should not do this (pure
> POSIX). Accelerate uses the GCD yes, but it's hardly any better than ATLAS.
> If OpenBLAS now uses the GCD on Mac someone in China should be flogged.

the use of gnu openmp is probably be the problem, forking and gomp is
only possible in very limited circumstances.
see e.g. https://github.com/xianyi/OpenBLAS/issues/294

maybe it will work with clangs intel based openmp which should be coming
the current workaround is single threaded openblas, python3.4 forkserver
or use atlas.

More information about the NumPy-Discussion mailing list