mutex: Add support for wound/wait style locks

[karo-tx-linux.git] / kernel / sched / core.c

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index e1a27f91872377c2526d28aead495e8241b1e92d..e8b335016c526594cd910a030c962099907d8518 100644 (file)
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -633,7 +633,19 @@ void wake_up_nohz_cpu(int cpu)
 static inline bool got_nohz_idle_kick(void)
 {
        int cpu = smp_processor_id();
-       return idle_cpu(cpu) && test_bit(NOHZ_BALANCE_KICK, nohz_flags(cpu));
+
+       if (!test_bit(NOHZ_BALANCE_KICK, nohz_flags(cpu)))
+               return false;
+
+       if (idle_cpu(cpu) && !need_resched())
+               return true;
+
+       /*
+        * We can't run Idle Load Balance on this CPU for this time so we
+        * cancel it and clear NOHZ_BALANCE_KICK
+        */
+       clear_bit(NOHZ_BALANCE_KICK, nohz_flags(cpu));
+       return false;
 }
 
 #else /* CONFIG_NO_HZ_COMMON */
@@ -1393,8 +1405,9 @@ static void sched_ttwu_pending(void)
 
 void scheduler_ipi(void)
 {
-       if (llist_empty(&this_rq()->wake_list) && !got_nohz_idle_kick()
-           && !tick_nohz_full_cpu(smp_processor_id()))
+       if (llist_empty(&this_rq()->wake_list)
+                       && !tick_nohz_full_cpu(smp_processor_id())
+                       && !got_nohz_idle_kick())
                return;
 
        /*
@@ -1417,7 +1430,7 @@ void scheduler_ipi(void)
        /*
         * Check if someone kicked us for doing the nohz idle load balance.
         */
-       if (unlikely(got_nohz_idle_kick() && !need_resched())) {
+       if (unlikely(got_nohz_idle_kick())) {
                this_rq()->idle_balance = 1;
                raise_softirq_irqoff(SCHED_SOFTIRQ);
        }