When I use openmpi mpirun --mca btl <arg1>, I find arg1 can be ofud, self, sm, openib, but www.open-mpi.org desn't explain those args. I can't understand the mean of "ofud", what different between "ofud" and "openib",
I also can't understand the different between "ibcm" and "rdmacm", when I use mpirun --mca btl_openib_cpc_include <arg2>.
maybe www.open-mpi.org can publish a openmpi's document to explain those args and principle.
wish your answer, best wish!