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Introduction to MPI - Exercise III Write a parallel program using MPI to sum integers from 1 to 1000, using Send and Receive. 1. Copy send_mpi.c from /home/appl/mpiworkshop 2. Edit the partially developed parallel program send.c by following the instructions in CAPITAL LETTTERS in the comments of the program. - THIS TIME, the master will be the process with the highest rank/id (not 0) - THIS TIME, you will not use an array to store the numbers to add 3. Compile/debug the program using the C compiler, linking in the MPI library: /usr/local/apps/mpich-1.2.5(mpich-1.2.7p1)/bin/mpicc -o send.exe send_mpi.c Or linking in the PGI library: /usr/local/apps/pgi-6.1/linux86/6.1/bin/pgcc -o send.exe send_mpi.c -lmpich 4. Run the executable, specifying the desired number of processes: /usr/local/apps/mpich-1.2.5(mpich-1.2.7p1)/bin/mpirun -np 2 send.exe (to run as 2 processes) /usr/local/apps/mpich-1.2.5(mpich-1.2.7p1)/bin/mpirun -np 3 send.exe (to run as 3 processes) 5. Debug and repeat, as necessary 6. (OPTIONAL) What happens when you run it on 4 nodes? 7. Modify send_mpi.c so that it will still work correctly even if the number of slave processes does not evenly divide into the number of elements to sum | |
