HP-MPI User's Guide (11th Edition)

Understanding HP-MPI
MPI options
Chapter 3 141
/opt/mpi/bin/mpirun -np 16 -e MPI_FLAGS=o
./a.out
Reordering ranks for the call
MPI_Cart_create(comm(size=16), ndims=2,
dims=[4 4], periods=[false
false], reorder=true)
Default mapping of processes would result
communication paths
between hosts :
0
between subcomplexes :
0
between hypernodes :
0
between CPUs within a hypernode/SMP:
24
Reordered mapping results communication paths
between hosts :
0
between subcomplexes :
0
between hypernodes :
0
between CPUs within a hypernode/SMP:
24
Reordering will not reduce overall
communication cost.
Void the optimization and adopted unreordered
mapping.
rank= 2 coords= 0 2 neighbors(u,d,l,r)= -1 6 1
3
rank= 0 coords= 0 0 neighbors(u,d,l,r)= -1 4 -1
1
rank= 1 coords= 0 1 neighbors(u,d,l,r)= -1 5 0
2
rank= 10 coords= 2 2 neighbors(u,d,l,r)= 6 14 9
11
rank= 2 inbuf(u,d,l,r)= -1 6 1 3
rank= 6 coords= 1 2 neighbors(u,d,l,r)= 2 10 5
7
rank= 7 coords= 1 3 neighbors(u,d,l,r)= 3 11 6
-1
rank= 4 coords= 1 0 neighbors(u,d,l,r)= 0 8 -1
5
rank= 0 inbuf(u,d,l,r)= -1 4 -1 1
rank= 5 coords= 1 1 neighbors(u,d,l,r)= 1 9 4 6