Ralph,
On Wed, May 28, 2014 at 9:33 PM, Ralph Castain <r...@open-mpi.org> wrote: > This is definetly what happens : only some tasks call MPI_Comm_free() > > > Really? I don't see how that can happen in loop_spawn - every process is > clearly calling comm_free. Or are you referring to the intercomm_create > test? > > yes, i am referring intercomm_create test about loop_spawn, i could not get any error on my single host single socket VM. (i tried --mca btl tcp,sm,self and --mca btl tcp,self) MPI_Finalize will end up calling ompi_dpm_dyn_finalize which causes the error message on the parent of intercomm_create. a necessary condition is ompi_comm_num_dyncomm > 1 /* which by the way sounds odd to me, should it be 0 ? */ which imho cannot happen if all communicators have been freed can you detail your full mpirun command line, the number of servers you are using, the btl involved and the ompi release that can be used to reproduce the issue ? i will try to reproduce this myself Cheers, Gilles