HP-MPI V2.3 for Linux Release Note

These tests are similar to the code found in $MPI_ROOT/help/hello_world.c and
$MPI_ROOT/help/ping_pong_ring.c. The ping_pong_ring test in
system_check.c defaults to a message size of 4096 bytes. An optional argument to
the system check application can be used to specify an alternate message size. The
environment variable HPMPI_SYSTEM_CHECK can be set to run a single test. Valid
values of HPMPI_SYSTEM_CHECK are:
• all – Runs both tests (the default value)
• hw – Runs the hello_world test
• ppr – Runs the ping_pong_ring test
If the HPMPI_SYSTEM_CHECK variable is set during an application run, that application
will run normally until MPI_Init is called. Before returning from MPI_Init, the
application will run the system check tests. When the system checks are completed,
the application will exit. This allows the normal application launch procedure to be
used during the test, including any job schedulers, wrapper scripts, and local
environment settings.
By default, the HPMPI_SYSTEM_CHECK API cannot be used if MPI_Init has already
been called, and the API will call MPI_Finalize before returning.
1.2.7.2 Default Message Size Changed For -ndd
When deferred deregistration is used, the operation of pinning memory is fast.
Therefore, the default setting for MPI_RDMA_MSGSIZE is 16384, 16384, 4194304 which
means any message over 16384 bytes is pinned for direct use in RDMA operations.
However, if deferred deregistration is not used (-ndd) then pinning memory is
expensive. In that case, the default setting for MPI_RDMA_MSGSIZE is 16384, 262144,
4194304 which means messages larger than 16384 and smaller than or equal to 262144
bytes are copied into pre-pinned memory using HP-MPI's middle message protocol
rather than being pinned and used in RDMA operations directly.
The middle message protocol performs better than the long message protocol if deferred
deregistration is not used.
For more information, see the MPI_RDMA_MSGSIZE section of the mpienv manpage.
1.2.7.3 MPICH2 Compatibility
This release enhances MPICH compatibility mode by supporting applications and
libraries that use the MPICH2 implementation. MPICH2 is not a standard, but rather
a specific implementation of the MPI-2.1 standard. HP-MPI provides MPICH2
compatibility with the following wrappers:
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