Pegasus Application Development¶
MPI and OpenMP modules are listed under Intel and GCC compilers. These MP libraries have been compiled and built with either the Intel compiler suite or the GNU compiler suite.
The following sections present the compiler invocation for serial and MP
executions. All compiler commands can be used for just compiling with
the -c flag (to create just the “.o” object files) or compiling and
linking (to create executables). To use a different (non-default)
compiler, first unload intel, swap the compiler environment, and then
reload the MP environment if necessary.
Note
Only one MP module should be loaded at a time.
Compiling Serial Code¶
Pegasus has Intel and GCC compilers.
| Vendor | Compiler | Module Command | Example |
|---|---|---|---|
| intel | icc (default) | module load intel |
icc -o foo.exe foo.c |
| intel | ifor (default) | module load intel |
ifort -o foo.exe foo.f90 |
| gnu | gcc | module load gcc |
gcc -o foo.exe foo.c |
| gnu | gcc | module load gcc |
gfortran -o foo.exe foo.f90 |
Configuring MPI on Pegasus¶
There are three ways to configure MPI on Pegasus. Choose the option that works best for your job requirements.
- Add the
module loadcommand to your startup files. This is most convenient for users requiring only a single version of MPI. This method works with all MPI modules. - Load the module in your current shell.
For current MPI versions, the
module loadcommand does not need to be in your startup files. Upon job submission, the remote processes will inherit the submission shell environment and use the proper MPI library. This method does not work with older versions of MPI. - Load the module in your job script.
This is most convenient for users requiring different versions of MPI
for different jobs. Ensure your script can execute the
module commandproperly. For job script information, see Scheduling Jobs on Pegasus.
Compiling Parallel Programs with MPI¶
Pegasus supports Intel MPI and OpenMP for Intel and GCC compilers.
The Message Passing Interface (MPI) library allows processes in parallel application to communicate with one another. There is no default MPI library in your Pegasus environment. Choose the desired MPI implementation for your applications by loading an appropriate MPI module. Recall that only one MPI module should be loaded at a time.
| Compiler | MPI | Module Command | Example |
|---|---|---|---|
| intel | Intel MPI | module load intel impi |
mpif90 -o foo.exe foo.f90 |
| intel | Intel MPI | module load intel impi |
mpicc -o foo.exe foo.c |
| intel | OpenMP | module load intel openmpi |
mpif90 -o foo.exe foo.f90 |
| intel | OpenMP | module load intel openmpi |
mpicc -o foo.exe foo.c |
| gcc | OpenMP | module load openmpi-gcc |
mpif90 -o foo.exe foo.f90 |
| gcc | OpenMP | module load openmpi-gcc |
mpicc -o foo.exe foo.c |