ParallelHowTo

Portland Compiler

It is possible to run CLaMS on multi-processor machines using MPI or OpenMP.

On the Ubuntu machines the PGF compiler suite is installed that has MPICH implemented.

In the following a short How to:

First it is necessary to make the path of the MPI libraries public by executing:

for 64bit machines:

. /opt/pgi/linux86-64/10.4/mpi.sh

for 32bit machines:

. /opt/pgi/linux86/10.4/mpi.sh

Then compile the needed programs by executing:

make useMPI=true

Before running the CLaMS script or a single program you have to execute:

ssh-add

This is necessary, because the processes communicate per ssh.

The programs must be called as following:

mpirun -np # [ --all-local ] program

# - number of processors
use the option --all-local for running it on the CPUs of the local machine only.

Intel Compiler

The MPICH2 Library (1.3.2p1) is installed in directory /usr/local/icg/icg1/local/mpich2-intel (for Intel C and Fortran compilers).

Add the bin subdirectory of the installation directory to your path:

PATH=/usr/local/icg/icg1/local/mpich2-intel/bin:$PATH
export PATH

To read the man pages set MANPATH to the following:

MANPATH=/usr/local/icg/icg1/local/mpich2-intel/share/man:$MANPATH
export MANPATH

The programs can be compiled with:

make useComp=ifc useMPI=true <progname>

Execute on <n> CPUs:

mpiexec -np <n> <progname>

It may be necessary to unset the memory limit:

ulimit -s unlimited