mpir/nodemap: use fallback collectives during init

In MPIR_nodeid_init use MPIR_Allgather_fallback and MPIR_Bcast_fallback
to avoid the complication of collective algorithm selection.

It causes issue here beause the bcast smp_new algorithm does not have
proper CVAR fallback check yet. The proper fix need add coll_attr to
most communicator checking routines, and will need coll_attr to be
universally added to all collective interfaces including nonblocking and
persistent collectives. Let's postpone that big change for now.

src/include/mpir_coll.h

@@ -42,6 +42,7 @@
  * are safe to use during init. They are all intra algorithms.
  */
 #define MPIR_Barrier_fallback    MPIR_Barrier_intra_dissemination
+#define MPIR_Bcast_fallback      MPIR_Bcast_intra_binomial
 #define MPIR_Allgather_fallback  MPIR_Allgather_intra_brucks
 #define MPIR_Allgatherv_fallback MPIR_Allgatherv_intra_brucks
 #define MPIR_Allreduce_fallback  MPIR_Allreduce_intra_recursive_doubling

src/util/mpir_nodemap.c

@@ -451,16 +451,16 @@ int MPIR_nodeid_init(void)
                              MPIR_Strerror(errno, strerrbuf, MPIR_STRERROR_BUF_SIZE), errno);
         my_hostname[MAX_HOSTNAME_LEN - 1] = '\0';
 
-        mpi_errno = MPIR_Allgather_impl(MPI_IN_PLACE, MAX_HOSTNAME_LEN, MPI_CHAR,
-                                        allhostnames, MAX_HOSTNAME_LEN, MPI_CHAR,
-                                        node_roots_comm, MPIR_ERR_NONE);
+        mpi_errno = MPIR_Allgather_fallback(MPI_IN_PLACE, MAX_HOSTNAME_LEN, MPI_CHAR,
+                                            allhostnames, MAX_HOSTNAME_LEN, MPI_CHAR,
+                                            node_roots_comm, MPIR_ERR_NONE);
         MPIR_ERR_CHECK(mpi_errno);
     }
 
     MPIR_Comm *node_comm = MPIR_Process.comm_world->node_comm;
     if (node_comm) {
-        mpi_errno = MPIR_Bcast_impl(allhostnames, MAX_HOSTNAME_LEN * MPIR_Process.num_nodes,
-                                    MPI_CHAR, 0, node_comm, MPIR_ERR_NONE);
+        mpi_errno = MPIR_Bcast_fallback(allhostnames, MAX_HOSTNAME_LEN * MPIR_Process.num_nodes,
+                                        MPI_CHAR, 0, node_comm, MPIR_ERR_NONE);
         MPIR_ERR_CHECK(mpi_errno);
     }