HP-MPI Version 2.2 for Linux Release Note

HP-MPI V2.2 for Linux Release Note

What’s in This Version

If the above option is applied so that the ptmalloc contained in HP-MPI is not used, then there

is a risk of MPI not being informed of when memory is returned to the system. This can be

alleviated with the setting MPI_USE_MALLOPT_SBRK_PROTECTION at runtime, which

essentially results in the libc malloc implementation not returning memory to the system.

There are cases where the MPI_USE_MALLOPT_SBRK_PROTECTION setting cannot keep libc from

returning memory to the system, in particular when multiple threads call malloc/free at the

same time. In these cases, the only remaining option is to disable HP-MPI's lazy

deregistration by giving the -ndd flag to mpirun.

Note that in the default case where the ptmalloc contained within HP-MPI is used, the above

cases are all avoided and lazy deregistration works correctly as is. So the above tunables are

only recommended for applications with special requirements concerning their malloc/free

usage.

Implied prun

HP-MPI also provides an implied prun mode. The implied prun mode allows the user to omit

the -prun argument from the mpirun command line with the use of the environment variable

MPI_USEPRUN.

Set the environment variable:

% setenv MPI_USEPRUN 1

HP-MPI will insert the -prun argument.

The following arguments are considered to be prun arguments:

• -n -N -m -w -x

• -e MPI_WORKDIR=/path will be translated to the prun argument --chdir=/path

• any argument that starts with -- and is not followed by a space

• -np will be translated to -n

• -prun will be accepted without warning.

The implied prun mode allows the use of HP-MPI appfiles. Currently, an appfile must be

homogenous in its arguments with the exception of -h and -np. The -h and -np arguments

within the appfile are discarded. All other arguments are promoted to the mpirun command

line. Additionally, arguments following -- are also processed.

Additional environment variables provided:

• MPI_PRUNOPTIONS

Allows additional prun options to be specified such as --label.