HP-MPI Version 2.2.5 for HP-UX Release Note

HP-MPI V2.2.5 for HP-UX Release Note
Known Problems and Workarounds
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• mpiCC.mpich contains a bug. The easiest workaround is to use mpicc.mpich instead. If
mpiCC.mpich is strongly desired, the file can be corrected with the following change.
The line which currently says
mpiCC=${mpiroot}/bin/mpicc
should say
case “$0” in
*.mpich)
mpiCC=${mpiroot}/bin/mpicc.mpich ;;
*)
mpiCC=${mpiroot}/bin/mpicc ;;
esac
• Profiling routines built for C calls will no longer cause the corresponding Fortran calls to
be wrapped automatically. In order to profile Fortran routines, separate wrappers need to
be written for the Fortran calls.
• Calling MPI from Fortran 90 programs
HP-MPI complies with the 1.2 version of the MPI standard, which defines bindings for
Fortran 77, but not Fortran 90. Some features of Fortran 90 may interact with MPI
non-blocking semantics to produce unexpected results. Consult the HP-MPI User’s Guide
for details.
• Running out of system resources
HP-UX imposes a limit to the number of file descriptors that application processes can
have open at one time. When running an HP-MPI application across multiple hosts, each
local process opens a socket to all remote processes. HP-UX counts these sockets as open
file descriptors, so an HP-MPI application with a large number of off-host processes can
reach the maximum. If your applications frequently exceed the maximum, ask your
system administrator to increase the limit, or use the -commd option with mpirun. Use of
this option results in a run with fewer sockets, but adds a performance penalty for
inter-host communications.
• Locating your instrumentation output file (prefix.instr) when you enable
instrumentation for multi-host runs
Whether you invoke mpirun on a host where at least one MPI process is running, or on a
host remote from all your MPI processes, HP-MPI writes the instrumentation output file
to the working directory on the host that is running rank 0.
• In order to use the -tv option to mpirun, the TOTALVIEW environment variable must be
set.
% export TOTALVIEW=/opt/totalview/bin/totalview