This is a 1.10-only fix: ensure we always have an event on the async progress thread so we don't consume cpu for no purpose. In the case of singletons, the OOB has no event it can place on the thread as there is no HNP being started, and so the thread spins.

Author: Ralph Castain

orte/mca/ess/base/ess_base_std_app.c

@@ -5,20 +5,20 @@
  * Copyright (c) 2004-2011 The University of Tennessee and The University
  *                         of Tennessee Research Foundation.  All rights
  *                         reserved.
- * Copyright (c) 2004-2005 High Performance Computing Center Stuttgart, 
+ * Copyright (c) 2004-2005 High Performance Computing Center Stuttgart,
  *                         University of Stuttgart.  All rights reserved.
  * Copyright (c) 2004-2005 The Regents of the University of California.
  *                         All rights reserved.
  * Copyright (c) 2010-2012 Oak Ridge National Labs.  All rights reserved.
  * Copyright (c) 2011-2013 Los Alamos National Security, LLC.  All rights
- *                         reserved. 
+ *                         reserved.
  * Copyright (c) 2013      Intel, Inc.  All rights reserved.
  * Copyright (c) 2014      Research Organization for Information Science
  *                         and Technology (RIST). All rights reserved.
  * $COPYRIGHT$
- * 
+ *
  * Additional copyrights may follow
- * 
+ *
  * $HEADER$
  */
 
@@ -73,6 +73,22 @@
 
 static void* orte_progress_thread_engine(opal_object_t *obj);
 static bool progress_thread_running = false;
+static struct timeval long_timeout = {
+    .tv_sec = 3600,
+    .tv_usec = 0
+};
+static opal_event_t block;
+/*
+ * If this event is fired, just restart it so that this event base
+ * continues to have something to block on.
+ */
+static void dummy_timeout_cb(int fd, short args, void *cbdata)
+{
+    opal_event_t *block = (opal_event_t*)cbdata;
+
+    opal_event_add(block, &long_timeout);
+}
+
 
 int orte_ess_base_app_setup(bool db_restrict_local)
 {
@@ -101,7 +117,12 @@ int orte_ess_base_app_setup(bool db_restrict_local)
 
     /* get a separate orte event base */
     orte_event_base = opal_event_base_create();
- 
+    /* add an event to the new event base (if there are no events,
+     * opal_event_loop() will return immediately) */
+    opal_event_set(orte_event_base, &block, -1, OPAL_EV_PERSIST,
+                   dummy_timeout_cb, &block);
+    opal_event_add(&block, &long_timeout);
+
     /* open and setup the state machine */
     if (ORTE_SUCCESS != (ret = mca_base_framework_open(&orte_state_base_framework, 0))) {
         ORTE_ERROR_LOG(ret);
@@ -135,7 +156,7 @@ int orte_ess_base_app_setup(bool db_restrict_local)
         error = "orte_oob_base_select";
         goto error;
     }
-    
+
     /* Runtime Messaging Layer */
     if (ORTE_SUCCESS != (ret = mca_base_framework_open(&orte_rml_base_framework, 0))) {
         ORTE_ERROR_LOG(ret);
@@ -147,7 +168,7 @@ int orte_ess_base_app_setup(bool db_restrict_local)
         error = "orte_rml_base_select";
         goto error;
     }
-    
+
     /* setup the errmgr */
     if (ORTE_SUCCESS != (ret = orte_errmgr_base_select())) {
         ORTE_ERROR_LOG(ret);
@@ -166,7 +187,7 @@ int orte_ess_base_app_setup(bool db_restrict_local)
         error = "orte_routed_base_select";
         goto error;
     }
-    
+
     /* database */
     if (ORTE_SUCCESS != (ret = mca_base_framework_open(&opal_db_base_framework, 0))) {
         ORTE_ERROR_LOG(ret);
@@ -194,7 +215,7 @@ int orte_ess_base_app_setup(bool db_restrict_local)
         error = "orte_grpcomm_base_select";
         goto error;
     }
-    
+
     /* non-daemon/HNP apps can only have the default proxy PLM
      * module open - provide a chance for it to initialize
      */
@@ -203,7 +224,7 @@ int orte_ess_base_app_setup(bool db_restrict_local)
         error = "orte_plm_init";
         goto error;
     }
-    
+
     /* construct the thread object */
     OBJ_CONSTRUCT(&orte_progress_thread, opal_thread_t);
     /* fork off a thread to progress it */
@@ -221,15 +242,15 @@ int orte_ess_base_app_setup(bool db_restrict_local)
         error = "orte_rml.enable_comm";
         goto error;
     }
-    
+
     /* setup my session directory */
     if (orte_create_session_dirs) {
         OPAL_OUTPUT_VERBOSE((2, orte_ess_base_framework.framework_output,
                              "%s setting up session dir with\n\ttmpdir: %s\n\thost %s",
                              ORTE_NAME_PRINT(ORTE_PROC_MY_NAME),
                              (NULL == orte_process_info.tmpdir_base) ? "UNDEF" : orte_process_info.tmpdir_base,
                              orte_process_info.nodename));
-        
+
         if (ORTE_SUCCESS != (ret = orte_session_dir(true,
                                                     orte_process_info.tmpdir_base,
                                                     orte_process_info.nodename, NULL,
@@ -238,22 +259,22 @@ int orte_ess_base_app_setup(bool db_restrict_local)
             error = "orte_session_dir";
             goto error;
         }
-        
+
         /* Once the session directory location has been established, set
            the opal_output env file location to be in the
            proc-specific session directory. */
         opal_output_set_output_file_info(orte_process_info.proc_session_dir,
                                          "output-", NULL, NULL);
     }
-    
+
     /* setup the routed info  */
     if (ORTE_SUCCESS != (ret = orte_routed.init_routes(ORTE_PROC_MY_NAME->jobid, NULL))) {
         ORTE_ERROR_LOG(ret);
         error = "orte_routed.init_routes";
         goto error;
     }
-    
-    
+
+
 #if OPAL_ENABLE_FT_CR == 1
     /*
      * Setup the SnapC
@@ -284,7 +305,7 @@ int orte_ess_base_app_setup(bool db_restrict_local)
 #else
     opal_cr_set_enabled(false);
 #endif
-    
+
     /* Initalize the CR setup
      * Note: Always do this, even in non-FT builds.
      * If we don't some user level tools may hang.
@@ -308,7 +329,7 @@ int orte_ess_base_app_setup(bool db_restrict_local)
     }
 
     return ORTE_SUCCESS;
-    
+
  error:
     if (!progress_thread_running) {
         /* can't send the help message, so ensure it
@@ -319,7 +340,7 @@ int orte_ess_base_app_setup(bool db_restrict_local)
     orte_show_help("help-orte-runtime.txt",
                    "orte_init:startup:internal-failure",
                    true, error, ORTE_ERROR_NAME(ret), ret);
-    
+
     return ret;
 }
 
@@ -362,11 +383,12 @@ int orte_ess_base_app_finalize(void)
     (void) mca_base_framework_close(&orte_state_base_framework);
 
     /* release the event base */
+    opal_event_del(&block);
     opal_event_base_free(orte_event_base);
 
     orte_session_dir_finalize(ORTE_PROC_MY_NAME);
-        
-    return ORTE_SUCCESS;    
+
+    return ORTE_SUCCESS;
 }
 
 /*
@@ -396,16 +418,16 @@ void orte_ess_base_app_abort(int status, bool report)
 
     /* Exit - do NOT do a normal finalize as this will very likely
      * hang the process. We are aborting due to an abnormal condition
-     * that precludes normal cleanup 
+     * that precludes normal cleanup
      *
-     * We do need to do the following bits to make sure we leave a 
+     * We do need to do the following bits to make sure we leave a
      * clean environment. Taken from orte_finalize():
      * - Assume errmgr cleans up child processes before we exit.
      */
-    
+
     /* CRS cleanup since it may have a named pipe and thread active */
     orte_cr_finalize();
-    
+
     /* If we were asked to report this termination, do so.
      * Since singletons don't start an HNP unless necessary, and
      * direct-launched procs don't have daemons at all, only send
@@ -425,7 +447,7 @@ void orte_ess_base_app_abort(int status, bool report)
          * have a chance to be sent */
         nanosleep(&tp, NULL);                                           \
     }
-    
+
     /* Now Exit */
     _exit(status);
 }