QLogic OFED+ Host Software User Guide, Rev. B

4–Running QLogic MPI on QLogic Adapters
QLogic MPI Details
When you are using a non-QLogic MPI that uses the TrueScale PSM layer,
ensure that the parallel job is contained on a single node and set the
PSM_DEVICES environment variable:
PSM_DEVICES="shm,self"
If you are using QLogic MPI, you do not need to set this environment variable; it is
set automatically if np == ppn.
When running on a single node with QLogic MPI, no infiniband adapter hardware
is required if -disable-dev-check is passed to mpirun.
mpihosts File Details
As noted in “Create the mpihosts File” on page 4-3, an mpihosts file (also called
a machines file, nodefile, or hostsfile) has been created in your current working
directory. This file names the nodes that the node programs may run.
The two supported formats for the mpihosts file are:
hostname1
hostname2
...
or
hostname1:process_count
hostname2:process_count
...
In the first format, if the -np count (number of processes to spawn in the mpirun
command) is greater than the number of lines in the machine file, the hostnames
will be repeated (in order) as many times as necessary for the requested number
of node programs.
In the second format, process_count can be different for each host, and is
normally the number of available processors on the node. When not specified, the
default value is one. The value of process_count determines how many node
programs will be started on that host before using the next entry in the mpihosts
file. When the full mpihosts file is processed, and there are additional processes
requested, processing starts again at the start of the file.
NOTE:
To create an mpihosts file, use the ibhosts program. It will generate a
list of available nodes that are already connected to the switch.
There are several alternative ways of specifying the mpihosts file:
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