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Introduction to MPI - Exercise I Write a parallel "Hello World Program" using MPI 1. Copy the file hello.c from /home/appl/mpiworkshop to a subdirectory called "mpiworkshop" under your home directory, and name it hello_mpi.c2. Edit hello_mpi.c into an MPI program in which each process outputs whether it is the boss or a servant process. - #include "mpi.h" - Initialize MPI by calling MPI_Init - Determine how many processes there are by calling MPI_Comm_size - Determine the rank of the current process by calling MPI_Comm_rank - Add a decision structure so that process #0 will print "Boss" and all other processes will print "Servant" and their procss id - Call MPI_Finalize 3. Compile/Debug the program using the MPI C compiler command "mpicc" 4. Copy the PBS file called "hello_mpi.pbs" from /home/appl/mpiworkshop to your working directory. 5. Examine/edit the PBS file as needed to submit the job to 2 nodes and add the path of mpicc and mpirun from /usr/local/apps/mpich-1.2.5 or mpich-1.2.7p1/bin/mpicc and mpirun respectively. 6. Submit the job to PBS using: qsub hello_mpi.pbs 7. Check the status of your job using: qstat or qstat -u $USER 8. Examine the PBS error and output files, and repeat steps as necessary until the output looks good. ls cat hello_mpi.pbs.eXXXX cat hello_mpi.pbs.oXXXX 9. Run checkprocs_me to make sure you have left no processes stranded on the nodes. 10. Modify the pbs file to run the job on 4 nodes. Submit the job and verify the output. | |
