Each parallel computing environment provides some mechanism for starting
parallel programs. Unfortunately, these mechanisms are very different from
one another. In an effort to make this aspect of parallel programming
portable as well, mpich contains a script called mpirun. This is
script is partially customized during the configuration process when mpich is
built. Therefore the actual ``source'' for mpirun is (for most
devices) in the file
mpirun.in in the mpich/util directory; some devices also
have additional files in their source directories (e.g.,
mpid/ch_p4). The most common
invocation of mpirun just specifies the number of processes and the
program to run:
mpirun -np 4 cpithe complete list of options for mpirun is obtained by running
mpirun -helpMore details on using mpirun may be found in the Users Guide for mpich.