Hello Tony,
Thank you very much for your reply. I am posting you the output of 'ps x', when 'mpirun -n 5 mpich-3.0.4/examples/hellow' freezes:
After that freeze, I killed mpirun with Ctrl + C:
"
marto@dragonfly% mpirun -n 5 mpich-3.0.4/examples/hellow
^C[mpiexec@dragonfly] Sending Ctrl-C to processes as requested
[mpiexec@dragonfly] Press Ctrl-C again to force abort
[proxy:0:0@dragonfly] HYDT_dmxu_poll_wait_for_event (./tools/demux/demux_poll.c:71): assert (!(pollfds[i].revents & ~POLLIN & ~POLLOUT & ~POLLHUP & ~POLLERR)) failed
[proxy:0:0@dragonfly] main (./pm/pmiserv/pmip.c:206): demux engine error waiting for event
[mpiexec@dragonfly] control_cb (./pm/pmiserv/pmiserv_cb.c:202): assert (!closed) failed
[mpiexec@dragonfly] HYDT_dmxu_poll_wait_for_event (./tools/demux/demux_poll.c:77): callback returned error status
[mpiexec@dragonfly] HYD_pmci_wait_for_completion (./pm/pmiserv/pmiserv_pmci.c:197): error waiting for event
[mpiexec@dragonfly] main (./ui/mpich/mpiexec.c:331): process manager error waiting for completion
"
The next relaunch of mpirun with 5 cores was successful. For completeness, I am attaching the output of 'ps x' after mpirun with 2 cores freezes, which it actually with 2 cores always does.
I hope this was helpful. I am looking forward to your reply.