HP XC System 3.x Software - Manual (Page 40)

Developing Parallel Applications
This section describes how to build and run parallel applications. The following topics are discussed:
•
Parallel Application Build Environment (page 40)
•
Building Parallel Applications (page 42)
For further information about developing parallel applications in the HP XC environment, refer to the following:
•
Launching Jobs with the srun Command (page 63)
•
Debugging Parallel Applications (page 53)
•
Chapter Advanced Topics (page 91)
Parallel Application Build Environment
This section discusses the parallel application build environment on an HP XC system.
The HP XC parallel application environment allows parallel application processes to be started and stopped
together on a large number of application cores, along with the I/O and process control structures to manage
these kinds of applications.
The HP XC system software uses the HP-MPI distributed memory programming model for building and running
parallel applications. In addition to using HP-MPI for parallel application development, OpenMP and Pthreads
can be used in conjunction with HP-MPI or separately under the HP XC ssystem software. The section discusses
these development tools as they relate to the HP XC system.
Modulefiles
The basics of your working environment are set up automatically by your system administrator during the
installation of HP XC. However, your application development environment can be modified by means of
modulefiles, as described in
"Overview of Modules" .
There are modulefiles available that you can load yourself to further tailor your environment to your specific
application development requirements. For example, the TotalView module is available for debugging
applications.
"Overview of Modules" provides instructions on how to list what modulefiles are available
for you to load, and how load a modulefile.
If you encounter problems accessing tools or commands (and associated manpages), ensure that required
modules are loaded on your system. If necessary, load required modules yourself, as described in
"Overview
of Modules" . Otherwise, contact your administrator.
HP-MPI
With the HP XC system software, you can use the HP-MPI distributed memory programming model for building
and running parallel applications. In this model, all data is private to each process. All intercore
communication within a parallel application is performed through calls to the HP-MPI message passing
library. Even though support for applications that use a shared-memory programming model is not available
at this time, individual cores within an application node can be used in the same application as separate
HP-MPI tasks. Applications that are MPI-based, and currently run on Linux (or Linux compatible) systems, can
be easily migrated to an HP XC cluster.
See the HP-MPI documentation for more information.
OpenMP
The OpenMP specification is a set of compiler directives that can be used to specify shared-memory parallelism
in Fortran and C/C++ programs. Both Intel and Portland Group Fortran and C/C++ compilers support
OpenMP.
Although OpenMP is designed for use on shared-memory architectures, OpenMP can be used on an HP XC
system within a node.
OpenMP can be used alone, or in conjunction with HP-MPI. For information about compiling programs using
OpenMP, refer to OpenMP documentation.
40 Developing Applications