mpirun - not enough slots available

Question

Usually when I use mpirun, I can "overload" it, using more processors than there acctually are on my computer. For example, on my four-core mac, I can run mpirun -np 29 python -c "print 'hey'" no problem. I'm on another machine now, which is throwing the following error:

$ mpirun -np 25 python -c "print 'hey'" -------------------------------------------------------------------------- There are not enough slots available in the system to satisfy the 25 slots  that were requested by the application:   python  Either request fewer slots for your application, or make more slots available for use. -------------------------------------------------------------------------- 

Why isn't "overclocking" mpirun working here? Is there a way I can overcome this error message and successfully run with more processors than are available?

Answer 1

Apparently oversubscribing can be attained using the "--oversubscribe" option with mpirun - did the trick for me with running torque/maui