Merge pull request #1257 from hppritcha/topic/disable_mpirun_for_native_slurm_crayxc

plm/alps: only use srun for Native SLURM

orte/mca/plm/alps/help-plm-alps.txt

@@ -39,3 +39,7 @@ the map for this application. This can be caused by a lack of
 an allocation, or by an error in the Open MPI code. Please check
 to ensure you have a ALPS allocation. If you do, then please pass
 the error to the Open MPI user's mailing list for assistance.
+#
+[slurm-not-supported]
+mpirun is not a supported launcher on Cray XC using Native SLURM.
+srun must be used to launch jobs on these systems.

orte/mca/plm/alps/plm_alps.h

@@ -46,6 +46,7 @@ ORTE_MODULE_DECLSPEC extern orte_plm_alps_component_t
     mca_plm_alps_component;
 ORTE_DECLSPEC extern orte_plm_base_module_t
     orte_plm_alps_module;
+extern bool mca_plm_alps_using_aprun;
 
 END_C_DECLS
 

orte/mca/plm/alps/plm_alps_component.c

@@ -43,6 +43,7 @@
  */
 const char *mca_plm_alps_component_version_string =
   "Open MPI alps plm MCA component version " ORTE_VERSION;
+bool mca_plm_alps_using_aprun = {true};
 
 
 /*
@@ -136,28 +137,19 @@ static int plm_alps_open(void)
 
 static int orte_plm_alps_component_query(mca_base_module_t **module, int *priority)
 {
-    int alps_wlm_active = 1;
 #if CRAY_WLM_DETECT
     char slurm[]="SLURM";
 
     if(!strcmp(slurm,wlm_detect_get_active())) {
-        alps_wlm_active = 0;
+        mca_plm_alps_using_aprun = false;
     }
 #endif
 
-    if (alps_wlm_active) {
     *priority = mca_plm_alps_component.priority;
     *module = (mca_base_module_t *) &orte_plm_alps_module;
     OPAL_OUTPUT_VERBOSE((1, orte_plm_base_framework.framework_output,
                         "%s plm:alps: available for selection",
                          ORTE_NAME_PRINT(ORTE_PROC_MY_NAME)));
-    } else {
-        *priority = 0;
-        *module = NULL;
-        OPAL_OUTPUT_VERBOSE((1, orte_plm_base_framework.framework_output,
-                            "%s plm:alps: not available, slurm present",
-                             ORTE_NAME_PRINT(ORTE_PROC_MY_NAME)));
-    }
 
     return ORTE_SUCCESS;
 }

orte/mca/plm/alps/plm_alps_module.c

@@ -121,6 +121,23 @@ static int plm_alps_init(void)
         return rc;
     }
 
+    /*
+     * owing to way the SLURM PLM component works, we can't use
+     * it on Cray XC systems as currently designed.  The problem
+     * is the MPI processes launched on the head node (where the
+     * ORTE_PROC_IS_HNP evalues to true) get launched by a daemon
+     * (mpirun) which is not a child of a slurmd daemon.  This
+     * means that any RDMA credentials obtained via the odls/alps
+     * local launcher are incorrect.
+     *
+     * So for now, we just don't support mpirun launched jobs
+     * on Cray XC systems using Native SLURM.
+     */
+    if (false == mca_plm_alps_using_aprun) {
+        orte_show_help("help-plm-alps.txt", "slurm-not-supported", true);
+        exit(-1);
+    }
+
     if (orte_do_not_launch) {
         /* must map daemons since we won't be launching them */
         orte_plm_globals.daemon_nodes_assigned_at_launch = true;