1 files changed, 28 insertions, 3 deletions

diff --git a/litmus/sched_cedf.c b/litmus/sched_cedf.c
index e29a9fe2a8e8..0707059597d6 100644
--- a/litmus/sched_cedf.c
+++ b/litmus/sched_cedf.c
@@ -411,6 +411,14 @@ static struct task_struct* cedf_schedule(struct task_struct * prev)
         int out_of_time, sleep, preempt, np, exists, blocks;
         struct task_struct* next = NULL;
 
+#ifdef CONFIG_RELEASE_MASTER
+        /* Bail out early if we are the release master.
+         * The release master never schedules any real-time tasks.
+         */
+        if (cluster->domain.release_master == entry->cpu)
+                return NULL;
+#endif
+
         raw_spin_lock(&cluster->lock);
         clear_will_schedule();
 
@@ -546,8 +554,18 @@ static void cedf_task_new(struct task_struct * t, int on_rq, int running)
                 entry = &per_cpu(cedf_cpu_entries, task_cpu(t));
                 BUG_ON(entry->scheduled);
 
-                entry->scheduled = t;
-                tsk_rt(t)->scheduled_on = task_cpu(t);
+#ifdef CONFIG_RELEASE_MASTER
+                if (entry->cpu != cluster->domain.release_master) {
+#endif
+                        entry->scheduled = t;
+                        tsk_rt(t)->scheduled_on = task_cpu(t);
+#ifdef CONFIG_RELEASE_MASTER
+                } else {
+                        /* do not schedule on release master */
+                        preempt(entry); /* force resched */
+                        tsk_rt(t)->scheduled_on = NO_CPU;
+                }
+#endif
         } else {
                 t->rt_param.scheduled_on = NO_CPU;
         }
@@ -731,6 +749,9 @@ static long cedf_activate_plugin(void)
 
                 if(!zalloc_cpumask_var(&cedf[i].cpu_map, GFP_ATOMIC))
                         return -ENOMEM;
+#ifdef CONFIG_RELEASE_MASTER
+                cedf[i].domain.release_master = atomic_read(&release_master_cpu);
+#endif
         }
 
         /* cycle through cluster and add cpus to them */
@@ -773,7 +794,11 @@ static long cedf_activate_plugin(void)
 
                                 entry->linked = NULL;
                                 entry->scheduled = NULL;
-                                update_cpu_position(entry);
+#ifdef CONFIG_RELEASE_MASTER
+                                /* only add CPUs that should schedule jobs */
+                                if (entry->cpu != entry->cluster->domain.release_master)
+#endif
+                                        update_cpu_position(entry);
                         }
                         /* done with this cluster */
                         break;