On Thu, 12 May 2016 06:27:43 +0000 (UTC) Sturla Molden <sturla.mol...@gmail.com> wrote:
> Allan Haldane <allanhald...@gmail.com> wrote: > > > You probably already know this, but I just wanted to note that the > > mpi4py module has worked around pickle too. They discuss how they > > efficiently transfer numpy arrays in mpi messages here: > > http://pythonhosted.org/mpi4py/usrman/overview.html#communicating-python-objects-and-array-data > > Unless I am mistaken, they use the PEP 3118 buffer interface to support > NumPy as well as a number of other Python objects. However, this protocol > makes buffer aquisition an expensive operation. Can you define "expensive"? > You can see this in Cython > if you use typed memory views. Assigning a NumPy array to a typed > memoryview (i,e, buffer acqisition) is slow. You're assuming this is the cost of "buffer acquisition", while most likely it's the cost of creating the memoryview object itself. Buffer acquisition itself only calls a single C callback and uses a stack-allocated C structure. It shouldn't be "expensive". Regards Antoine. _______________________________________________ NumPy-Discussion mailing list NumPy-Discussion@scipy.org https://mail.scipy.org/mailman/listinfo/numpy-discussion
