Thank you very much for your help!
I tried to run the same test of ring_c from standard examples in
Open MPI 1.4.3 distribution. If I ran as you described from the
command line, it worked without any problem with sm btl
included(with --mca btl self,sm,openib). However, if I use sm
btl(with --mca btl self,sm,openib), and ran ring_c from an in-house
script, it showed the same issue as I described in my previous
email, it will hang at MPI_Init(...) call. I think this issue is related to
some environmental setting in the script. Do you have any hints,
any prerequisite of system environmental configuration to work with
sm btl layer in Open MPI?