The examples/test directory contains subdirectories of small programs that systematically test a large subset of the MPI functions. The command
make testing
in the mpich/examples/test directory will cause these programs to be
compiled, linked, executed, and their output to be compared with the expected
output. Linking all these test programs takes up considerable space, so you
might want to do
make clean
in the test directory afterwards. The individual parts of MPI
(point-to-point, collective, topology, etc.) can be tested separately by
make testing
in the separate subdirectories for examples/test.