From 7cc5879bdd7534605e92f28f33405a7a8a3dc4b3 Mon Sep 17 00:00:00 2001
From: Ralph Castain <rhc@open-mpi.org>
Date: Mon, 21 Dec 2015 09:47:27 -0800
Subject: [PATCH] Fix the default slot mapping in rank file mapper

---
 orte/mca/rmaps/rank_file/rmaps_rank_file.c | 88 +++++++++++++++-------
 1 file changed, 59 insertions(+), 29 deletions(-)

diff --git a/orte/mca/rmaps/rank_file/rmaps_rank_file.c b/orte/mca/rmaps/rank_file/rmaps_rank_file.c
index 854451aea6..a43d8d7bed 100644
--- a/orte/mca/rmaps/rank_file/rmaps_rank_file.c
+++ b/orte/mca/rmaps/rank_file/rmaps_rank_file.c
@@ -196,10 +196,42 @@ static int orte_rmaps_rf_map(orte_job_t *jdata)
             rank = vpid_start + k;
             /* get the rankfile entry for this rank */
             if (NULL == (rfmap = (orte_rmaps_rank_file_map_t*)opal_pointer_array_get_item(&rankmap, rank))) {
-                /* all ranks must be specified */
-                orte_show_help("help-rmaps_rank_file.txt", "missing-rank", true, rank, orte_rankfile);
-                rc = ORTE_ERR_SILENT;
-                goto error;
+                /* if we were give a default slot-list, then use it */
+                if (NULL != opal_hwloc_base_slot_list) {
+                    slots = opal_hwloc_base_slot_list;
+                    /* take the next node off of the available list */
+                    node = NULL;
+                    OPAL_LIST_FOREACH(nd, &node_list, orte_node_t) {
+                        /* if adding one to this node would oversubscribe it, then try
+                         * the next one */
+                        if (nd->slots <= (int)nd->num_procs) {
+                            continue;
+                        }
+                        /* take this one */
+                        node = nd;
+                        break;
+                    }
+                    if (NULL == node) {
+                        /* all would be oversubscribed, so take the least loaded one */
+                        k = UINT32_MAX;
+                        OPAL_LIST_FOREACH(nd, &node_list, orte_node_t) {
+                            if (nd->num_procs < k) {
+                                k = nd->num_procs;
+                                node = nd;
+                            }
+                        }
+                    }
+                    /* if we still have nothing, then something is very wrong */
+                    if (NULL == node) {
+                        rc = ORTE_ERR_OUT_OF_RESOURCE;
+                        goto error;
+                    }
+                } else {
+                    /* all ranks must be specified */
+                    orte_show_help("help-rmaps_rank_file.txt", "missing-rank", true, rank, orte_rankfile);
+                    rc = ORTE_ERR_SILENT;
+                    goto error;
+                }
             } else {
                 if (0 == strlen(rfmap->slot_list)) {
                     /* rank was specified but no slot list given - that's an error */
@@ -208,34 +240,32 @@ static int orte_rmaps_rf_map(orte_job_t *jdata)
                     goto error;
                 }
                 slots = rfmap->slot_list;
-            }
+                /* find the node where this proc was assigned */
+                node = NULL;
+                OPAL_LIST_FOREACH(nd, &node_list, orte_node_t) {
+                    if (NULL != rfmap->node_name &&
+                        0 == strcmp(nd->name, rfmap->node_name)) {
+                        node = nd;
+                        break;
+                    } else if (NULL != rfmap->node_name &&
+                               (('+' == rfmap->node_name[0]) &&
+                                (('n' == rfmap->node_name[1]) ||
+                                 ('N' == rfmap->node_name[1])))) {
 
-            /* find the node where this proc was assigned */
-            node = NULL;
-            OPAL_LIST_FOREACH(nd, &node_list, orte_node_t) {
-                if (NULL != rfmap->node_name &&
-                    0 == strcmp(nd->name, rfmap->node_name)) {
-                    node = nd;
-                    break;
-                } else if (NULL != rfmap->node_name &&
-                           (('+' == rfmap->node_name[0]) &&
-                            (('n' == rfmap->node_name[1]) ||
-                             ('N' == rfmap->node_name[1])))) {
-
-                    relative_index=atoi(strtok(rfmap->node_name,"+n"));
-                    if ( relative_index >= (int)opal_list_get_size (&node_list) || ( 0 > relative_index)){
-                        orte_show_help("help-rmaps_rank_file.txt","bad-index", true,rfmap->node_name);
-                        ORTE_ERROR_LOG(ORTE_ERR_BAD_PARAM);
-                        return ORTE_ERR_BAD_PARAM;
+                        relative_index=atoi(strtok(rfmap->node_name,"+n"));
+                        if ( relative_index >= (int)opal_list_get_size (&node_list) || ( 0 > relative_index)){
+                            orte_show_help("help-rmaps_rank_file.txt","bad-index", true,rfmap->node_name);
+                            ORTE_ERROR_LOG(ORTE_ERR_BAD_PARAM);
+                            return ORTE_ERR_BAD_PARAM;
+                        }
+                        root_node = (orte_node_t*) opal_list_get_first(&node_list);
+                        for(tmp_cnt=0; tmp_cnt<relative_index; tmp_cnt++) {
+                            root_node = (orte_node_t*) opal_list_get_next(root_node);
+                        }
+                        node = root_node;
+                        break;
                     }
-                    root_node = (orte_node_t*) opal_list_get_first(&node_list);
-                    for(tmp_cnt=0; tmp_cnt<relative_index; tmp_cnt++) {
-                        root_node = (orte_node_t*) opal_list_get_next(root_node);
-                    }
-                    node = root_node;
-                    break;
                 }
-
             }
             if (NULL == node) {
                 orte_show_help("help-rmaps_rank_file.txt","bad-host", true, rfmap->node_name);