OPEN MPI¶

Open MPI is an open source implementation of MPI (message-passing interface), the industry-standard specification for writing message-passing programs. Message passing is a programming model that gives the programmer explicit control over interprocess communication.

The MPI specification was developed by the MPI Forum, a group of software developers, computer vendors, academics, and computer-science researchers whose goal was to develop a standard for writing message-passing programs that would be efficient, flexible, and portable.

The outcome, known as the MPI Standard, was first published in 1993; its most recent version (MPI-4.0) was published in June 2021. Open MPI includes all MPI 3.1-compliant routines.

For more information about Open MPI, see <https://www.open-mpi.org>.

The MPI standards are available at <https://www.mpi-forum.org>.

MAN PAGE SYNTAX¶

Man pages for Open MPI and Open MPI I/O routines are named according to C syntax, that is, they begin with the prefix MPI_, all in uppercase, and the first letter following the MPI_ prefix is also uppercase. The rest of the letters in the routine are all lowercase, for example, MPI_Comm_get_attr <#mpi-comm-get-attr>.

ENVIRONMENT¶

To fine-tune your Open MPI environment, you can either use arguments to the mpirun <#man1-mpirun> or mpiexec <#man1-mpiexec> commands, or you can use MCA parameters.

For more information on arguments, see the mpirun(1) <#man1-mpirun> man page.

For a complete listing of MCA parameters and their descriptions, issue the command ompi_info --all. See ompi_info(1) <#man1-ompi-info> for more information.

ERRORS¶

See MPI Errors <#mpi-errors> for details about error values.

See also:

Copyright¶

2003-2025, The Open MPI Community