if (count < size) {
XBT_WARN("MPI_bcast_arrival_scatter use default MPI_bcast.");
Colls::bcast(buf, count, datatype, root, comm);
if (count < size) {
XBT_WARN("MPI_bcast_arrival_scatter use default MPI_bcast.");
Colls::bcast(buf, count, datatype, root, comm);