PSN-EDF: use FMLP+ priority-boosting order

boost by request time, not issue time

1 files changed, 19 insertions, 8 deletions

diff --git a/litmus/sched_psn_edf.c b/litmus/sched_psn_edf.c
index 2e5b9c9d75d7..7b12689ab61a 100644
--- a/litmus/sched_psn_edf.c
+++ b/litmus/sched_psn_edf.c
@@ -412,6 +412,12 @@ int psnedf_fmlp_lock(struct litmus_lock* l)
         if (!is_realtime(t))
                 return -EPERM;
 
+        preempt_disable();
+
+        TRACE_CUR("want FMLP sem %p\n", sem);
+
+        boost_priority(t);
+
         spin_lock_irqsave(&sem->wait.lock, flags);
 
         if (sem->owner) {
@@ -422,10 +428,9 @@ int psnedf_fmlp_lock(struct litmus_lock* l)
                 /* FIXME: interruptible would be nice some day */
                 set_task_state(t, TASK_UNINTERRUPTIBLE);
 
+                TRACE_CUR("blocking on FMLP sem %p\n", sem);
                 __add_wait_queue_tail_exclusive(&sem->wait, &wait);
 
-                TS_LOCK_SUSPEND;
-
                 /* release lock before sleeping */
                 spin_unlock_irqrestore(&sem->wait.lock, flags);
 
@@ -434,8 +439,14 @@ int psnedf_fmlp_lock(struct litmus_lock* l)
                  * there is only one wake up per release.
                  */
 
+                TS_LOCK_SUSPEND;
+
+                preempt_enable_no_resched();
+
                 schedule();
 
+                preempt_disable();
+
                 TS_LOCK_RESUME;
 
                 /* Since we hold the lock, no other task will change
@@ -446,12 +457,13 @@ int psnedf_fmlp_lock(struct litmus_lock* l)
                 /* it's ours now */
                 sem->owner = t;
 
-                /* mark the task as priority-boosted. */
-                boost_priority(t);
-
                 spin_unlock_irqrestore(&sem->wait.lock, flags);
         }
 
+        TRACE_CUR("got FMLP sem %p\n", sem);
+
+        preempt_enable();
+
         return 0;
 }
 
@@ -469,6 +481,8 @@ int psnedf_fmlp_unlock(struct litmus_lock* l)
                 goto out;
         }
 
+        TRACE_CUR("releasing FMLP sem %p\n", sem);
+
         /* we lose the benefit of priority boosting */
 
         unboost_priority(t);
@@ -476,9 +490,6 @@ int psnedf_fmlp_unlock(struct litmus_lock* l)
         /* check if there are jobs waiting for this resource */
         next = __waitqueue_remove_first(&sem->wait);
         if (next) {
-                /* boost next job */
-                boost_priority(next);
-
                 /* next becomes the resouce holder */
                 sem->owner = next;