| Hilfe-Text | This module provides the Open MPI Message Passing Interface bindings (mpicc,
mpicxx, mpifort (mpif77 and mpif90)). The corresponding compiler suite
(gnu/8.2) module should (and automatically will) be loaded first.
Documentation:
See man pages of mpicc, mpicxx, mpifort (mpif77, mpif90) and mpirun,
e.g. 'man mpicc'.
For additional help see 'http://www.open-mpi.org/faq/'.
Compiling and executing MPI-programs:
Instead of the usual compiler commands, you should compile and link your
mpi-program with mpicc, mpicxx, mpifort (mpif77 and mpif90). What e.g.
'mpicc' is really doing can be displayed via command 'mpicc -show'.
Frequently one needs '-I${MPI_INC_DIR}' in addition.
The MPI-libraries can be found in
$MPI_LIB_DIR
Example for compiling an MPI program with Open MPI:
module load mpi/openmpi/4.0-gnu-8.2
mpicc -O2 mpi_application.c -o mpi_application.exe # for C programs
mpicxx -O2 mpi_application.cxx -o mpi_application.exe # for C++ programs
mpifort -O2 mpi_application.f -o mpi_application.exe # for Fortran programs
# GNU: Optimization level '-O2' results in substantially faster executables.
For additional help see 'http://www.open-mpi.org/faq/?category=mpi-apps'.
Example for executing the MPI program using 4 cores on the local node:
module load mpi/openmpi/4.0-gnu-8.2
mpirun -np 4 `pwd`/mpi_application.exe
Example PBS snippet for submitting the program on 2 x 8 = 16 cores:
#PBS -l nodes=2:ppn=8
module load mpi/openmpi/4.0-gnu-8.2
mpirun $PBS_O_WORKDIR/mpi_application.exe
The mpirun command automatically determines the number of workers
and the hosts for the workers via PBS-TM and/or $PBS_NODEFILE.
Open MPI offers an abundance on parameters using the MCA. For more
information, check ompi_info using:
ompi_info --param all all --level 9
Good examples of mpirun's parameters are:
mpirun -np 4 --report-bindings --mca pml ucx mpi_application
For details on library and include directories please call
module show mpi/openmpi/4.0-gnu-8.2
The man pages, environment variables and compiler commands
are available after loading 'mpi/openmpi/4.0-gnu-8.2'.
In case of problems, please contact 'bwunicluster-hotline (at) lists.kit.edu'
or submit a trouble ticket at 'http://www.support.bwhpc-c5.de'.
The full version is: 4.0.1-gnu-8.2 |