[Beowulf] mpi slow pairs

[Michael Di Domenico]

does anyone have any mpi code that checks for slow pairs between mpi
ranks.  and no i don't me a micro benchmark that i can run a bunch of
times and tabulate the results.

i mean a program i can submit with a bunch of ranks and have it test
the throughput between each and spit out a result for all the pairs

i need to test the pair wise throughput across a large machine.  i'm
seeing a strange infiniband issue where some pairs are full speed but
others are not