OpenMPI

http://www.open-mpi.org/faq/

MCA parameter files

If you want to permanently use some MCA parameter settings, you can create a file $HOME/.openmpi/mca-params.conf, e.g.:

cat $HOME/.openmpi/mca-params.conf
btl_tcp_if_exclude = lo,eth1

Running applications on Multiprocessors/Multicores

Process can be bound to specific sockets and cores on nodes by choosing right options of mpirun.

• Process binding
• Rankfiles

Debugging applications on Multiprocessors/Multicores

• Serial Debugger (Gdb)
  • 1. Attach to individual MPI processes after they are running.
    For example, launch your MPI application as normal with mpirun. Then login to the node(s) where your application is running and use the --pid option to gdb to attach to your application.
  • 2. Use mpirun to launch xterms (or equivalent) with serial debuggers.

     shell$ mpirun -np 4 xterm -e gdb my_mpi_application

• Parallel Debugers
  • TotalView
  • DDT