That is correct and has always been the behavior. If you want OMPI to respect host order, you have to use the sequential mapper instead of the default round-robin mapper.
On Thu, Feb 4, 2010 at 4:37 PM, Eugene Loh <eugene....@sun.com> wrote: > I'd check the man page, but since I just rewrote it I don't think that's > going to help! > > I have two nodes, A and B, and I run "mpirun -hostfile myhostfile > -tag-output hostname" with five different hostfiles. Here is what I get: > > B slots=2 > B slots=2 > A slots=2 > A slots=2 > B B B B A A A A > > B slots=2 > A slots=2 > B slots=2 > A slots=2 > B B B B A A A A > > A slots=2 > B slots=2 > A slots=2 > B slots=2 > A A A A B B B B > > B slots=2 > A slots=2 > A slots=2 > B slots=2 > A A A A B B B B > > A slots=1 > B slots=1 > A slots=1 > B slots=1 > A slots=1 > B slots=1 > A slots=1 > B slots=1 > A A A A B B B B > > This is with openmpi-1.7a1r22109. After each hostfile, I list the nodes I > get in MPI rank order. So, it appears the hostfile cannot be used to > control in what order processes are mapped to nodes. It can only be used to > specify the total number of slots per node. Slots are filled up one node at > a time. I assume we don't want to make any claims about the node order? > _______________________________________________ > users mailing list > us...@open-mpi.org > http://www.open-mpi.org/mailman/listinfo.cgi/users >
