[MPICH] MPI_Comm_spawn and hosts

[Wei-keng Liao]

I have a simple program that calls MPI_Comm_spawn() to spawn a group of 
MPI processes. I found that the hosts running parent and child groups are 
overlapped. I ran The job ran though PBS with enough compute nodes 
allocated for parents and children to be disjoint.

How do I ensure the hosts running parents and children are not overlapped?

Wei-keng