Merge commit 'v3.17' into next

1 files changed, 21 insertions, 17 deletions

diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 31cc02ebc54..579712f4e9d 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -477,6 +477,9 @@ struct root_domain {
 	cpumask_var_t span;
 	cpumask_var_t online;
 
+	/* Indicate more than one runnable task for any CPU */
+	bool overload;
+
 	/*
 	 * The bit corresponding to a CPU gets set here if such CPU has more
 	 * than one runnable -deadline task (as it is below for RT tasks).
@@ -884,20 +887,10 @@ enum {
 #undef SCHED_FEAT
 
 #if defined(CONFIG_SCHED_DEBUG) && defined(HAVE_JUMP_LABEL)
-static __always_inline bool static_branch__true(struct static_key *key)
-{
-	return static_key_true(key); /* Not out of line branch. */
-}
-
-static __always_inline bool static_branch__false(struct static_key *key)
-{
-	return static_key_false(key); /* Out of line branch. */
-}
-
 #define SCHED_FEAT(name, enabled)					\
 static __always_inline bool static_branch_##name(struct static_key *key) \
 {									\
-	return static_branch__##enabled(key);				\
+	return static_key_##enabled(key);				\
 }
 
 #include "features.h"
@@ -1196,7 +1189,7 @@ extern void init_sched_rt_class(void);
 extern void init_sched_fair_class(void);
 extern void init_sched_dl_class(void);
 
-extern void resched_task(struct task_struct *p);
+extern void resched_curr(struct rq *rq);
 extern void resched_cpu(int cpu);
 
 extern struct rt_bandwidth def_rt_bandwidth;
@@ -1218,15 +1211,26 @@ static inline void add_nr_running(struct rq *rq, unsigned count)
 
 	rq->nr_running = prev_nr + count;
 
-#ifdef CONFIG_NO_HZ_FULL
 	if (prev_nr < 2 && rq->nr_running >= 2) {
+#ifdef CONFIG_SMP
+		if (!rq->rd->overload)
+			rq->rd->overload = true;
+#endif
+
+#ifdef CONFIG_NO_HZ_FULL
 		if (tick_nohz_full_cpu(rq->cpu)) {
-			/* Order rq->nr_running write against the IPI */
-			smp_wmb();
-			smp_send_reschedule(rq->cpu);
+			/*
+			 * Tick is needed if more than one task runs on a CPU.
+			 * Send the target an IPI to kick it out of nohz mode.
+			 *
+			 * We assume that IPI implies full memory barrier and the
+			 * new value of rq->nr_running is visible on reception
+			 * from the target.
+			 */
+			tick_nohz_full_kick_cpu(rq->cpu);
 		}
-       }
 #endif
+	}
 }
 
 static inline void sub_nr_running(struct rq *rq, unsigned count)