Do not use nodes that are flagged as down or do-not-use for this map. Modify error output to reflect possible reasons no nodes would be available

This commit was SVN r23333.

orte/mca/rmaps/base/help-orte-rmaps-base.txt

@@ -49,7 +49,10 @@ no nodes were found or all the available nodes were already used.
 Note that since the -nolocal option was given no processes can be 
 launched on the local node.
 [orte-rmaps-base:no-available-resources]
-There are no nodes allocated to this job.
+No nodes are available for this job, either due to a failure to
+allocate nodes to the job, or allocated nodes being marked
+as unavailable (e.g., down, rebooting, or a process attempting
+to be relocated to another node when none are available).
 [orte-rmaps-base:all-available-resources-used]
 All nodes which are allocated for this job are already filled.
 #

orte/mca/rmaps/base/rmaps_base_support_fns.c

@@ -57,20 +57,31 @@ int orte_rmaps_base_get_target_nodes(opal_list_t *allocated_nodes, orte_std_cntr
     /** set default answer */
     *total_num_slots = 0;
     
-    /* if the hnp was allocated, include it */
+    /* if the hnp was allocated, include it unless flagged not to */
     if (orte_hnp_is_allocated) {
         node = (orte_node_t*)opal_pointer_array_get_item(orte_node_pool, 0);
-        OBJ_RETAIN(node);
-        opal_list_append(allocated_nodes, &node->super);
+        if (ORTE_NODE_STATE_UP == node->state) {
+            OBJ_RETAIN(node);
+            opal_list_append(allocated_nodes, &node->super);
+        } else if (ORTE_NODE_STATE_DO_NOT_USE == node->state) {
+            /* clear this for future use */
+            node->state = ORTE_NODE_STATE_UP;
+        }
     }
     
-    /* add everything in the node pool */
+    /* add everything in the node pool that can be used */
     for (i=1; i < orte_node_pool->size; i++) {
         if (NULL != (node = (orte_node_t*)opal_pointer_array_get_item(orte_node_pool, i))) {
             /* ignore nodes that are "down" */
             if (ORTE_NODE_STATE_DOWN == node->state) {
                 continue;
             }
+            /* ignore nodes that are marked as do-not-use for this mapping */
+            if (ORTE_NODE_STATE_DO_NOT_USE == node->state) {
+                /* reset the state so it can be used another time */
+                node->state = ORTE_NODE_STATE_UP;
+                continue;
+            }
             /* retain a copy for our use in case the item gets
              * destructed along the way
              */