GSN-EDF: add release master support

1 files changed, 42 insertions, 9 deletions

diff --git a/litmus/sched_gsn_edf.c b/litmus/sched_gsn_edf.c
index e350d5668f..0d24244bee 100644
--- a/litmus/sched_gsn_edf.c
+++ b/litmus/sched_gsn_edf.c
@@ -393,6 +393,12 @@ static struct task_struct* gsnedf_schedule(struct task_struct * prev)
         int out_of_time, sleep, preempt, np, exists, blocks;
         struct task_struct* next = NULL;
 
+        /* Bail out early if we are the release master.
+         * The release master never schedules any real-time tasks.
+         */
+        if (gsnedf.release_master == entry->cpu)
+                return NULL;
+
         spin_lock(&gsnedf_lock);
         clear_will_schedule();
 
@@ -508,18 +514,23 @@ static void gsnedf_task_new(struct task_struct * t, int on_rq, int running)
         TRACE("gsn edf: task new %d\n", t->pid);
 
         spin_lock_irqsave(&gsnedf_lock, flags);
+
+        /* setup job params */
+        release_at(t, litmus_clock());
+
         if (running) {
                 entry = &per_cpu(gsnedf_cpu_entries, task_cpu(t));
                 BUG_ON(entry->scheduled);
-                entry->scheduled = t;
-                t->rt_param.scheduled_on = task_cpu(t);
-        } else
+                if (entry->cpu != gsnedf.release_master) {
+                        entry->scheduled = t;
+                        tsk_rt(t)->scheduled_on = task_cpu(t);
+                } else
+                        tsk_rt(t)->scheduled_on = NO_CPU;
+        } else {
                 t->rt_param.scheduled_on = NO_CPU;
+        }
         t->rt_param.linked_on          = NO_CPU;
 
-        /* setup job params */
-        release_at(t, litmus_clock());
-
         gsnedf_job_arrival(t);
         spin_unlock_irqrestore(&gsnedf_lock, flags);
 }
@@ -678,6 +689,29 @@ static long gsnedf_admit_task(struct task_struct* tsk)
         return 0;
 }
 
+static long gsnedf_activate_plugin(void)
+{
+        int cpu;
+        cpu_entry_t *entry;
+
+        heap_init(&gsnedf_cpu_heap);
+        gsnedf.release_master = atomic_read(&release_master_cpu);
+
+        for_each_online_cpu(cpu) {
+                entry = &per_cpu(gsnedf_cpu_entries, cpu);
+                heap_node_init(&entry->hn, entry);
+                atomic_set(&entry->will_schedule, 0);
+                entry->linked    = NULL;
+                entry->scheduled = NULL;
+                if (cpu != gsnedf.release_master) {
+                        TRACE("GSN-EDF: Initializing CPU #%d.\n", cpu);
+                        update_cpu_position(entry);
+                } else {
+                        TRACE("GSN-EDF: CPU %d is release master.\n", cpu);
+                }
+        }
+        return 0;
+}
 
 /*      Plugin object   */
 static struct sched_plugin gsn_edf_plugin __cacheline_aligned_in_smp = {
@@ -696,7 +730,8 @@ static struct sched_plugin gsn_edf_plugin __cacheline_aligned_in_smp = {
         .inherit_priority       = gsnedf_inherit_priority,
         .return_priority        = gsnedf_return_priority,
 #endif
-        .admit_task             = gsnedf_admit_task
+        .admit_task             = gsnedf_admit_task,
+        .activate_plugin        = gsnedf_activate_plugin,
 };
 
 
@@ -711,8 +746,6 @@ static int __init init_gsn_edf(void)
                 entry = &per_cpu(gsnedf_cpu_entries, cpu);
                 gsnedf_cpus[cpu] = entry;
                 atomic_set(&entry->will_schedule, 0);
-                entry->linked    = NULL;
-                entry->scheduled = NULL;
                 entry->cpu       = cpu;
                 entry->hn        = &gsnedf_heap_node[cpu];
                 heap_node_init(&entry->hn, entry);