G-EDF: make use of release_master interface

The current release_master setting is copied when activating
the plugin. Changing it during execution is currently not
supported.

1 files changed, 14 insertions, 2 deletions

diff --git a/litmus/sched_gedf.c b/litmus/sched_gedf.c
index 7725d92fd5..87469253a8 100644
--- a/litmus/sched_gedf.c
+++ b/litmus/sched_gedf.c
@@ -339,6 +339,12 @@ static struct task_struct* gedf_schedule(struct task_struct * prev)
         int out_of_time, sleep, preempt, exists, blocks;
         struct task_struct* next = NULL;
 
+        /* Bail out earlier if we are the release master.
+         * The release master never schedules any real-time tasks.
+         */
+        if (gedf.release_master == entry->cpu)
+                return NULL;
+
         TRACE_TASK(prev, "invoked gedf_schedule.\n");
 
         /* sanity checking */
@@ -540,14 +546,20 @@ static long gedf_activate_plugin(void)
         cpu_entry_t *entry;
 
         heap_init(&gedf_cpu_heap);
+        gedf.release_master = atomic_read(&release_master_cpu);
+
         for_each_online_cpu(cpu) {
-                TRACE("G-EDF: Initializing CPU #%d.\n", cpu);
                 entry = &per_cpu(gedf_cpu_entries, cpu);
                 heap_node_init(&entry->hn, entry);
                 entry->linked    = NULL;
                 entry->scheduled = NULL;
                 entry->picked    = 0;
-                update_cpu_position(entry);
+                if (cpu != gedf.release_master) {
+                        TRACE("G-EDF: Initializing CPU #%d.\n", cpu);
+                        update_cpu_position(entry);
+                } else {
+                        TRACE("G-EDF: CPU %d is release master.\n", cpu);
+                }
         }
         return 0;
 }