Recently I often meet hangs and seg faults with different command lines and
there are "ml" functions in the stack trace.
When I just turn "ml" off by do -mca coll ^ml, problems disappear.
oshrun -np 4 --map-by node --display-map ./ring_oshmem
fails with seg fault while
oshrun -np 4 --map-by node --display-map -mca coll ^ml ./ring_oshmem
The "ml" priority is low (27), but it could have issues during comm_query
(it does all initialization staff there).
"Ml" is unreliable component. So It may be reasonable do not to build this
component by default to avoid such problems.
What do you think?