Add call to ping_nodes based upon health_check_interval.

Also call ping_nodes even when SlurmdTimeout=0 so that
non-responsive nodes can be returned to service.

src/slurmctld/controller.c

@@ -1014,13 +1014,18 @@ static void *_slurmctld_background(void *no_data)
 	last_sched_time = last_checkpoint_time = last_group_time = now;
 	last_purge_job_time = last_trigger = now;
 	last_timelimit_time = last_assert_primary_time = now;
-	if (slurmctld_conf.slurmd_timeout) {
-		/* We ping nodes that haven't responded in SlurmdTimeout/2,
+	if (slurmctld_conf.slurmd_timeout ||
+	    slurmctld_conf.health_check_interval) {
+		/* We ping nodes that haven't responded in SlurmdTimeout/3,
 		 * but need to do the test at a higher frequency or we might
 		 * DOWN nodes with times that fall in the gap. */
-		ping_interval = slurmctld_conf.slurmd_timeout / 3;
-	} else
-		ping_interval = 60 * 60 * 24 * 356;	/* one year */
+		ping_interval = MIN((slurmctld_conf.slurmd_timeout/3),
+				    slurmctld_conf.health_check_interval);
+	} else {
+		/* This will just ping non-responding nodes
+		 * and restore them to service */
+		ping_interval = 100;	/* 100 seconds */
+	}
 	last_ping_node_time = now + (time_t)MIN_CHECKIN_TIME - ping_interval;
 	last_ping_srun_time = now;
 	last_node_acct = now;