Jeff, On Wed, May 28, 2014 at 8:31 PM, Jeff Squyres (jsquyres) > To be totally clear: MPI says it is erroneous for only some (not all) processes in a communicator to call MPI_COMM_FREE. So if that's the real problem, then the discussion about why the parent(s) is(are) trying to contact the children is moot -- the test is erroneous, and erroneous application behavior is undefined.
This is definetly what happens : only some tasks call MPI_Comm_free() i will commit my changes and the initially reported issue is solved :-) about the "bonus points" : v1.8 does not have this issue i digged it and bottom line, the parent (who did not call MPI_Comm_free unlike the children) calls ompi_dpm_base_dyn_finalize, which tries to isend the already exited tasks. bottom line, in pml_ob1_sendreq.h line 450 with v1,8 mca_bml_base_btl_array_get_size(&endpoint->btl_eager) = 0 nothing is sent but isend is reported successful with trunk mca_bml_base_btl_array_get_size(&endpoint->btl_eager) = 1 and then try to send the message => BOUM i found various things that seem counter intuitive to me and will summarize all this tomorrow. Cheers, Gilles
