User guide

4–Running MPI on QLogic Adapters
Open MPI
IB0054606-02 A 4-3
These wrapper scripts pass most options on to the underlying compiler. Use the
documentation for the underlying compiler (gcc, icc, pgcc, etc. ) to determine what
options to use for your application.
QLogic strongly encourages using the wrapper compilers instead of attempting to
link to the Open MPI libraries manually. This allows the specific implementation of
Open MPI to change without forcing changes to linker directives in users'
Makefiles.
Create the mpihosts File
Create an MPI hosts file in the same working directory where Open MPI is
installed. The MPI hosts file contains the host names of the nodes in your cluster
that run the examples, with one host name per line. Name this file mpihosts. The
contents can be in the following format:
More details on the mpihosts file can be found in “mpihosts File Details” on
page 4-12.
Running Open MPI Applications
The Open MPI choices available from mpi-selector --list are:
 openmpi_gcc-1.4.3
 openmpi_gcc_qlc-1.4.3
 openmpi_intel_qlc-1.4.3
 openmpi_pgi_qlc-1.4.3.
Table 4-2. Command Line Options for Scripts
Command Meaning
man mpicc
(mpif90,
mpicxx, etc.)
Provides help
-showme Lists each of the compiling and linking commands that would
be called without actually invoking the underlying compiler
-showme:compile Shows the compile-time flags that would be supplied to the
compiler
-showme:link Shows the linker flags that would be supplied to the compiler
for the link phase.