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

Understanding HP-MPI
Running applications on HP-UX and Linux
Chapter 366
Some features like mpirun -stdio processing are unavailable.
Rank assignments within HP-MPI are determined by the way prun
chooses mapping at runtime.
The -np option is not allowed with -prun. The following mpirun
options are allowed with -prun:
% $MPI_ROOT/bin/mpirun [-help] [-version] [-jv] [-i
<spec>] [-universe_size=#] [-sp <paths>] [-T] [-prot]
[-spawn] [-1sided] [-tv] [-e var[=val]] -prun <prun
options> <program> [<args>]
For more information on prun usage:
% man prun
The following examples assume the system has the Quadrics Elan
interconnect and is a collection of 2-CPU nodes.
% $MPI_ROOT/bin/mpirun -prun -N4 ./a.out
will run a.out with 4 ranks, one per node, ranks are cyclically
allocated.
n00 rank1
n01 rank2
n02 rank3
n03 rank4
% $MPI_ROOT/bin/mpirun -prun -n4 ./a.out
(assuming nodes have 2 processors/cores each) will run a.out with 4
ranks, 2 ranks per node, ranks are block allocated. Two nodes used.
n00 rank1
n00 rank2
n01 rank3
n01 rank4
Other forms of usage include allocating the nodes you wish to use,
which creates a subshell. Then jobsteps can be launched within that
subshell until the subshell is exited.
% $MPI_ROOT/bin/mpirun -prun -A -N6
This allocates 6 nodes and creates a subshell.
% $MPI_ROOT/bin/mpirun -prun -n4 -m block ./a.out