Product specifications

5–Using QLogic MPI
QLogic MPI Details
IB6054601-00 H 5-13
A
Additionally, you can explicitly configure for the number of contexts you want to
use with the cfgports module parameter. This will override the default settings
(on the QLE7240 and QLE7280) based on the number of CPUs present on each
node. See “InfiniPath Hardware Contexts on the QLE7240 and QLE7280” on
page 5-11.
Context Sharing Error Messages
The error message when the context limit is exceeded is:
No free InfiniPath contexts available on /dev/ipath
This message appears when the application starts.
Error messages related to contexts may also be generated by ipath_checkout
or mpirun. For example:
PSM found 0 available contexts on InfiniPath device
The most likely cause is that the cluster has processes using all the available
PSM contexts. Clean up these processes before restarting the job.
Running in Shared Memory Mode
QLogic MPI supports running exclusively in shared memory mode; no QLogic
adapter is required for this mode of operation. This mode is used for running
applications on a single node rather than on a cluster of nodes.
To enable shared memory mode, use either a single node in the mpihosts file or
use these options with mpirun:
$ mpirun -np=<N> -ppn=<N>
<N>
needs to be equal in both cases.
When you are using a non-QLogic MPI that uses the InfiniPath 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 host channel adapter
hardware is required if -disable-dev-check is passed to mpirun.
NOTE:
For this release, <N> must be ≤ 64.