mpirun -np 4 --host node1,node2,node1,node2 ./app Is this what you want?
On Thu, Mar 1, 2012 at 10:57 AM, Claudio Pastorino < claudio.pastor...@gmail.com> wrote: > Dear all, > I apologize in advance if this is not the right list to post this. I > am a newcomer and please let me know if I should be sending this to > another list. > > I program MPI trying to do HPC parallel programs. In particular I > wrote a parallel code > for molecular dynamics simulations. The program splits the work in a > matrix of procs and > I send messages along rows and columns in an equal basis. I learnt > that the typical > arrangement of cartesian topology is not usually the best option, > because in a matrix, let's say of 4x4 procs with quad procs, the > procs are arranged so that > through columns one stays inside the same quad proc and through rows > you are always going out to the network. This means procs are > arranged as one quad per row. > > I try to explain this for a 2x2 case. The cartesian topology does this > assignment, typically: > cartesian mpi_comm_world > 0,0 --> 0 > 0,1 --> 1 > 1,0 --> 2 > 1,1 --> 3 > The question is, how do I get a "user defined" assignment such as: > 0,0 --> 0 > 0,1 --> 2 > 1,0 --> 1 > 1,1 --> 3 > > ? > > Thanks in advance and I hope to have made this more or less > understandable. > Claudio > _______________________________________________ > users mailing list > us...@open-mpi.org > http://www.open-mpi.org/mailman/listinfo.cgi/users >
