Using Valgrind

Don't underesitmate the power of Valgrind! You can simply invoke it as shown below.

mpiexec -l -n 2 valgrind spmd_sum_3 1000

Valgrind also has direct hooks for MPI. See the page at:

http://valgrind.org/docs/manual/mc-manual.html#mc-manual.mpiwrap

for more details.