I use openMp in a C-extension that has an interface with Python. In its simplest form I do this:
== code == #pragma omp parallel { #pragma omp for for(int i=0; i<10; i++) { // multiply some matrices in C } } == end of code == This all works fine, and it uses the number of cores I have. But if I import numpy in my python session BEFORE I run the code, then it uses only 1 core (and omp_num_procs also returns 1 core, instead of the maximum of 8 cores). So how does numpy affect openMp, and does it have anything to do with the GIL or something? I don't use any Python object in my parallel region. Any help would be appreciated! Wout -- http://mail.python.org/mailman/listinfo/python-list