previous_reduce_scatter_module 144 ompi/mca/coll/hcoll/coll_hcoll.h mca_coll_base_module_t *previous_reduce_scatter_module; previous_reduce_scatter_module 76 ompi/mca/coll/hcoll/coll_hcoll_module.c hcoll_module->previous_reduce_scatter_module = NULL;