[Pkg-openmpi-maintainers] Bug#849974: openmpi: not enough slots available

[Graham Inggs]

Alternatively, add the '--oversubscribe' option to the mpirun command 
line, i.e.:

mpirun --map-by socket:OVERSUBSCRIBE -np 4 python -c "print 'hello'"

...or set the 'OMPI_MCA_rmaps_base_oversubscribe' environment variable:

export OMPI_MCA_rmaps_base_oversubscribe=1
mpirun -np 4 python -c "print 'hello'"

(from bug #850229)