1 files changed, 14 insertions, 7 deletions

diff --git a/kernel/sched.c b/kernel/sched.c
index 0f2def82229..ac3f5cc3bb5 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -864,21 +864,28 @@ static void deactivate_task(struct task_struct *p, runqueue_t *rq)
 #ifdef CONFIG_SMP
 static void resched_task(task_t *p)
 {
-        int need_resched, nrpolling;
+        int cpu;
 
         assert_spin_locked(&task_rq(p)->lock);
 
-        /* minimise the chance of sending an interrupt to poll_idle() */
-        nrpolling = test_tsk_thread_flag(p,TIF_POLLING_NRFLAG);
-        need_resched = test_and_set_tsk_thread_flag(p,TIF_NEED_RESCHED);
-        nrpolling |= test_tsk_thread_flag(p,TIF_POLLING_NRFLAG);
+        if (unlikely(test_tsk_thread_flag(p, TIF_NEED_RESCHED)))
+                return;
+
+        set_tsk_thread_flag(p, TIF_NEED_RESCHED);
+
+        cpu = task_cpu(p);
+        if (cpu == smp_processor_id())
+                return;
 
-        if (!need_resched && !nrpolling && (task_cpu(p) != smp_processor_id()))
-                smp_send_reschedule(task_cpu(p));
+        /* NEED_RESCHED must be visible before we test POLLING_NRFLAG */
+        smp_mb();
+        if (!test_tsk_thread_flag(p, TIF_POLLING_NRFLAG))
+                smp_send_reschedule(cpu);
 }
 #else
 static inline void resched_task(task_t *p)
 {
+        assert_spin_locked(&task_rq(p)->lock);
         set_tsk_need_resched(p);
 }
 #endif