Fixed GSN-EDF to handle correct wakeup of tasks that just exited a

semaphore.

3 files changed, 23 insertions, 19 deletions

diff --git a/kernel/litmus.c b/kernel/litmus.c
index dba56a2905..f182ca093a 100644
--- a/kernel/litmus.c
+++ b/kernel/litmus.c
@@ -517,10 +517,9 @@ int  litmus_dummy_scheduler_setup(int cmd, void __user *parameter);
 long litmus_dummy_sleep_next_period(void);
 long litmus_dummy_enter_np(struct task_struct *task);
 long litmus_dummy_exit_np(struct task_struct *task);
-long litmus_dummy_inherit_priority(struct task_struct *offspring,
-                                   struct task_struct *deceased);
-long litmus_dummy_return_priority(struct task_struct *offspring,
-                                  struct task_struct *deceased);
+long litmus_dummy_inherit_priority(struct pi_semaphore *sem,
+                                   struct task_struct *new_waiter);
+long litmus_dummy_return_priority(struct pi_semaphore *sem);
 
 
 #define CHECK(func) {\
diff --git a/kernel/sched.c b/kernel/sched.c
index 9e70cde182..667a1279c1 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -3799,6 +3799,7 @@ static void __wake_up_common(wait_queue_head_t *q, unsigned int mode,
                 wait_queue_t *curr = list_entry(tmp, wait_queue_t, task_list);
                 unsigned flags = curr->flags;
 
+                set_rt_flags((struct task_struct*)curr->private, RT_F_EXIT_SEM);
                 if (curr->func(curr, mode, sync, key) &&
                                 (flags & WQ_FLAG_EXCLUSIVE) && !--nr_exclusive)
                         break;
@@ -3818,7 +3819,8 @@ static void __pi_wake_up_common(struct pi_semaphore *s, unsigned int mode,
         list_for_each_safe(tmp, next, &s->wait.task_list) {
                 wait_queue_t *curr = list_entry(tmp, wait_queue_t, task_list);
                 unsigned flags = curr->flags;
-        
+
+                set_rt_flags((struct task_struct*)curr->private, RT_F_EXIT_SEM);
                 if (curr->func(curr, mode, sync, key) &&
                                 (flags & WQ_FLAG_EXCLUSIVE) && !--nr_exclusive)
                         break;
diff --git a/kernel/sched_gsn_edf.c b/kernel/sched_gsn_edf.c
index 02f5ac924b..abf88a8f79 100644
--- a/kernel/sched_gsn_edf.c
+++ b/kernel/sched_gsn_edf.c
@@ -411,24 +411,27 @@ static void gsnedf_wake_up_task(struct task_struct *task)
               task->pid, task->time_slice);
         task->state = TASK_RUNNING;
 
-        /* FIXME: We need to take suspensions because of semaphores into
-         *        account! If a job resumes after being suspended due to acquiring
-         *        a semaphore, it should never be treated as a new job release.
+        /* We need to take suspensions because of semaphores into
+         * account! If a job resumes after being suspended due to acquiring
+         * a semaphore, it should never be treated as a new job release.
          */
-        if (is_tardy(task)) {
-                /* new sporadic release */
-                prepare_new_release(task);
-                sched_trace_job_release(task);
-        }
-        else if (task->time_slice)
-                /* came back in time before deadline
-                 */
+        if (get_rt_flags(task) == RT_F_EXIT_SEM) {
                 set_rt_flags(task, RT_F_RUNNING);
-        
+        } else {
+                if (is_tardy(task)) {
+                        /* new sporadic release */
+                        prepare_new_release(task);
+                        sched_trace_job_release(task);
+                }
+                else if (task->time_slice)
+                        /* came back in time before deadline
+                         */
+                        set_rt_flags(task, RT_F_RUNNING);
+        }
+
         queue_lock_irqsave(&gsnedf_lock, flags);
         gsnedf_job_arrival(task);
-        queue_unlock_irqrestore(&gsnedf_lock, flags);
-                        
+        queue_unlock_irqrestore(&gsnedf_lock, flags);   
 }
 
 static void gsnedf_task_blocks(struct task_struct *t)