QLogic OFED+ Host Software User Guide, Rev. B

A–mpirun Options Summary
Spawn Options
-np np
This option specifies the number of processes to spawn. If this option is not set,
then the environment variable MPI_NPROCS is checked. If MPI_NPROCS is not
set, the default is to determine the number of processes based on the number of
hosts in the machinefile -M or the list of hosts -H.
-ppn processes-per-node
This option creates up to the specified number of processes per node.
By default, a limit is enforced that depends on how many InfiniPath contexts are
supported by the node (depends on the hardware type and the number of
InfiniPath cards present).
InfiniPath context (port) sharing is supported, beginning with the InfiniPath 2.0
release. This feature allows running up to four times as many processes per node
as was previously possible, with a small additional overhead for each shared
context.
Context sharing is enabled automatically if needed. Use of the full number of
available contexts is assumed. To restrict the number of contexts, use the
environment variable PSM_SHAREDCONTEXTS_MAX to divide the available
number of contexts.
Context sharing behavior can be overriden by using the environment variable
PSM_SHAREDCONTEXTS. Setting this variable to zero disables context sharing,
and jobs that require more than the available number of contexts cannot be run.
Setting this variable it to one (the default) causes context sharing to be enabled if
needed.
-rcfile node-shell-script
This is the startup script for setting the environment on nodes. Before starting
node programs, mpirun checks to see if a file called .mpirunrc exists in the
user’s home directory. If the file exists, it is sourced into the running remote
shell. Use -rcfile node-shell-script or .mpirunrc to set paths and other
environment variables such as LD_LIBRARY_PATH.
Default: $HOME/.mpirunrc
Spawn Options
-distributed [=on|off]
This option controls use of the distributed mpirun job spawning mechanism. The
default is on. To change the default, put this option in the global
mpirun.defaults file or a user-local file (see the environment variable
PSC_MPIRUN_DEFAULTS_PATH for details). When the option appears more than
once on the command line, the last setting controls the behavior.
Default: on.
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