PAI::change_prio(): check work before locking

1 files changed, 8 insertions, 7 deletions

diff --git a/litmus/sched_gsn_edf.c b/litmus/sched_gsn_edf.c
index 37f7821dca50..37294111bb0c 100644
--- a/litmus/sched_gsn_edf.c
+++ b/litmus/sched_gsn_edf.c
@@ -723,15 +723,16 @@ static void gsnedf_change_prio_pai_tasklet(struct task_struct *old_prio,
         struct tasklet_struct* step;
         unsigned long flags;
         
-        raw_spin_lock_irqsave(&gsnedf_lock, flags);
-        
-        for(step = gsnedf_pending_tasklets.head; step != NULL; step = step->next) {
-                if(step->owner == old_prio) {
-                        TRACE("%s: Found tasklet to flush: %d\n", __FUNCTION__, step->owner->pid);
-                        step->owner = new_prio;
+        if(gsnedf_pending_tasklets.head != NULL) {
+                raw_spin_lock_irqsave(&gsnedf_lock, flags);
+                for(step = gsnedf_pending_tasklets.head; step != NULL; step = step->next) {
+                        if(step->owner == old_prio) {
+                                TRACE("%s: Found tasklet to change: %d\n", __FUNCTION__, step->owner->pid);
+                                step->owner = new_prio;
+                        }
                 }
+                raw_spin_unlock_irqrestore(&gsnedf_lock, flags);
         }
-        raw_spin_unlock_irqrestore(&gsnedf_lock, flags);
 }
 
 #endif  // end PAI