MPICH at the ITP Opteron Cluster
| MPICH Building a MPI program MPICH Documentation |
MPICH
MPICH is a freely available, portable implementation of MPI (MPI stands for the Message Passing Interface).
Implementation
The current version of MPICH is 1.2.7p2. (out of date!)
Setting up the MPICH environment
To use the MPICH software it is helpful to add the MPI path to your PATH variable. In order to do so you can do this interactive or you place the following entry after the global definitions in your ".bashrc" file, if you want to use this module permanent after every login. Please load only one of the MPICH modules:
| Compiler | .bashrc entry / modulefile command |
|---|---|
| GNU Compiler GNU 4.1.2 (gcc, gfortran) |
module load mpich/1.2.7p1_gnu-4.1.2 |
Building a MPI program
MPI include directives
You have to add the following include file to your source files:
#include "mpi.h" (in C/C++)
include 'mpif.h' (in Fortran)
You can find these include files under:
| Compiler | Include path |
|---|---|
| GNU Compiler GNU 4.1.2 (gcc, gfortran) |
/opt/mpich/1.2.7p1/include |
MPI compiler scripts
Simply use MPI's "wrapper" compilers to compile your MPI applications. That is, instead of using (for example) gcc to compile your program, use mpicc. MPICH provides a wrapper compiler for four languages:
| Language | Wrapper compiler name | Compiler script |
|---|---|---|
| C | mpicc | C Compiler (gcc or icc) |
| C++ | mpicxx or mpiCC |
C++ Compiler (g++ or icpc) |
| F77 | mpif77 | Fortran 77 Compiler (f77 or ifort) |
| F90 | mpif90 | Fortran 90 Compiler (gfortran or ifort) |
This is a simple compiler call that compiles the C program myprog.c .
mpicc -o myprog myprog.c
MPI libraries
If you do not use the compiler scripts you have to add the MPI libraries to your link command explicitly. Here are the paths to the libraries:
| compiler | Library path |
|---|---|
| GNU Compiler GNU 4.1.2 (gcc, gfortran) |
/opt/mpich/1.2.7p1/lib |
MPICH Documentation
You can find the MPICH documentation on the following web and man pages:
- MPICH
- Man Pages: mpicc(1), mpicxx(1), mpiCC(1), mpif77(1), mpif90(1), mpirun(1).