Okay, my e-mail below just crossed with another one explaining that
behavior has recently been intentionally changed. I'll go chew on that
for a while.
Eugene Loh wrote:
If I specify two hosts and no "slots" information, processes should be
started in equal numbers on the two hosts. But, how should they be
ranked? "Block" or "cyclic" (round robin)? Did we change this
behavior recently?
% ompi_info | grep "Open MPI:"
Open MPI: 1.3.4a1r22009
% mpirun -H saem9,saem10 -np 8 -tag-output hostname
[1,0]<stdout>:saem9
[1,1]<stdout>:saem9
[1,2]<stdout>:saem9
[1,3]<stdout>:saem9
[1,4]<stdout>:saem10
[1,5]<stdout>:saem10
[1,6]<stdout>:saem10
[1,7]<stdout>:saem10
% ompi_info | grep "Open MPI:"
Open MPI: 1.3.4a1r22051
% mpirun -H saem9,saem10 -np 8 -tag-output hostname
[1,0]<stdout>:saem9
[1,1]<stdout>:saem10
[1,2]<stdout>:saem9
[1,3]<stdout>:saem10
[1,4]<stdout>:saem9
[1,5]<stdout>:saem10
[1,6]<stdout>:saem9
[1,7]<stdout>:saem10
