verifying SMP

[Gabriel J. Weinstock]

Hi,
  Does anyone know a good way to test if a certain process is running on 
different CPUs on an SMP cluster node? For example, if one were to mpirun -np 
4 prog where the machines file looked like
node1:2
node2:2
  how could you verify that one process is being started on each CPU? Using 
top is one option, but then you're still inferring where the process is 
running. We're seeing funny numbers in our code and would like to verify 
where Linux is scheduling processes.
Thanks,
Gabe