Running MPI Programs on the Cray SV1

1. Log on to the SV1
   • ssh cray (or "seymour", "seymour.tjhsst.edu")
   • enter the password
   • Type "bash" to use the shell you are used to
     - for instance, you'll be able to use tab completion and the arrow keys to repeat commands
   • check the current directory path: use "pwd" (print working directory)
     The path should be: /local/yourusername/

2. Run an MPI program:
   1. compile your MPI program: cc -o myprog myprog.c
      This creates an output, executable file called "myprog"
   2. Run your MPI program: mpirun -np 4 myprog
      This runs myprog with 5 processes
   3. alternative: cc myprog.c
      creates the output file "a.out"
      run this with mpirun -np 4 a.out

3. Sign out of the Cray: "exit"
4. MPI Resources
   • Message Passing Basics, from John Urbanic, Pittsburgh Supercomputing Center
   • Syntax of MPI calls - Index for the Message Passing Interface Standard
   • MPI home page
   • MPI PROGRAMS:
     • helloWorldMPI.c
     • greetings.c
     • greetings.cpp
     • recipMPI.c (same as master0/slave0.pvm)
     • trap.c
     • trap.cpp
     • Josh Blake's MPI example, Makefile, sample hostfile
     • Other intro MPI programs (from the LAM Tutorial slides)
       • simpleMpi.c
       • simpleMpi.cpp
       • simple2Mpi.c
       • simple2Mpi.cpp
       • simple3Mpi.c
       • simple3Mpi.cpp
     • mpi-julia.c, generates a julia set with portions allocated to "slave" processes. MPI version
     • mpi-basicwin.c, Mpiglut (MPI for GLUT - c version)
       This program is modeled on Jeff Grafton's mpi-julia program,
       this version generates a parabola by splitting up the computation
       among n "slaves"
   • MPI Links