sched/fair: Remove rq's runnable avg

The current rq->avg is not used at all since its merge into the kernel,
and the code is in the scheduler's hot path, so remove it.

Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Signed-off-by: Yuyang Du <yuyang.du@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: arjan@linux.intel.com
Cc: bsegall@google.com
Cc: fengguang.wu@intel.com
Cc: len.brown@intel.com
Cc: morten.rasmussen@arm.com
Cc: pjt@google.com
Cc: rafael.j.wysocki@intel.com
Cc: umgwanakikbuti@gmail.com
Cc: vincent.guittot@linaro.org
Link: http://lkml.kernel.org/r/1436918682-4971-2-git-send-email-yuyang.du@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

kernel/sched/debug.c

@@ -68,13 +68,8 @@ static void print_cfs_group_stats(struct seq_file *m, int cpu, struct task_group
 #define PN(F) \
 	SEQ_printf(m, "  .%-30s: %lld.%06ld\n", #F, SPLIT_NS((long long)F))
 
-	if (!se) {
-		struct sched_avg *avg = &cpu_rq(cpu)->avg;
-		P(avg->runnable_avg_sum);
-		P(avg->avg_period);
+	if (!se)
 		return;
-	}
-
 
 	PN(se->exec_start);
 	PN(se->vruntime);

kernel/sched/fair.c

@@ -2724,19 +2724,12 @@ static inline void __update_group_entity_contrib(struct sched_entity *se)
 	}
 }
 
-static inline void update_rq_runnable_avg(struct rq *rq, int runnable)
-{
-	__update_entity_runnable_avg(rq_clock_task(rq), cpu_of(rq), &rq->avg,
-			runnable, runnable);
-	__update_tg_runnable_avg(&rq->avg, &rq->cfs);
-}
 #else /* CONFIG_FAIR_GROUP_SCHED */
 static inline void __update_cfs_rq_tg_load_contrib(struct cfs_rq *cfs_rq,
 						 int force_update) {}
 static inline void __update_tg_runnable_avg(struct sched_avg *sa,
 						  struct cfs_rq *cfs_rq) {}
 static inline void __update_group_entity_contrib(struct sched_entity *se) {}
-static inline void update_rq_runnable_avg(struct rq *rq, int runnable) {}
 #endif /* CONFIG_FAIR_GROUP_SCHED */
 
 static inline void __update_task_entity_contrib(struct sched_entity *se)
@@ -2940,7 +2933,6 @@ static inline void dequeue_entity_load_avg(struct cfs_rq *cfs_rq,
  */
 void idle_enter_fair(struct rq *this_rq)
 {
-	update_rq_runnable_avg(this_rq, 1);
 }
 
 /*
@@ -2950,7 +2942,6 @@ void idle_enter_fair(struct rq *this_rq)
  */
 void idle_exit_fair(struct rq *this_rq)
 {
-	update_rq_runnable_avg(this_rq, 0);
 }
 
 static int idle_balance(struct rq *this_rq);
@@ -2959,7 +2950,6 @@ static int idle_balance(struct rq *this_rq);
 
 static inline void update_entity_load_avg(struct sched_entity *se,
 					  int update_cfs_rq) {}
-static inline void update_rq_runnable_avg(struct rq *rq, int runnable) {}
 static inline void enqueue_entity_load_avg(struct cfs_rq *cfs_rq,
 					   struct sched_entity *se,
 					   int wakeup) {}
@@ -4258,10 +4248,9 @@ enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags)
 		update_entity_load_avg(se, 1);
 	}
 
-	if (!se) {
-		update_rq_runnable_avg(rq, rq->nr_running);
+	if (!se)
 		add_nr_running(rq, 1);
-	}
+
 	hrtick_update(rq);
 }
 
@@ -4319,10 +4308,9 @@ static void dequeue_task_fair(struct rq *rq, struct task_struct *p, int flags)
 		update_entity_load_avg(se, 1);
 	}
 
-	if (!se) {
+	if (!se)
 		sub_nr_running(rq, 1);
-		update_rq_runnable_avg(rq, 1);
-	}
+
 	hrtick_update(rq);
 }
 
@@ -6005,9 +5993,6 @@ static void __update_blocked_averages_cpu(struct task_group *tg, int cpu)
 		 */
 		if (!se->avg.runnable_avg_sum && !cfs_rq->nr_running)
 			list_del_leaf_cfs_rq(cfs_rq);
-	} else {
-		struct rq *rq = rq_of(cfs_rq);
-		update_rq_runnable_avg(rq, rq->nr_running);
 	}
 }
 
@@ -7988,8 +7973,6 @@ static void task_tick_fair(struct rq *rq, struct task_struct *curr, int queued)
 
 	if (numabalancing_enabled)
 		task_tick_numa(rq, curr);
-
-	update_rq_runnable_avg(rq, 1);
 }
 
 /*

kernel/sched/sched.h

@@ -595,8 +595,6 @@ struct rq {
 #ifdef CONFIG_FAIR_GROUP_SCHED
 	/* list of leaf cfs_rq on this cpu: */
 	struct list_head leaf_cfs_rq_list;
-
-	struct sched_avg avg;
 #endif /* CONFIG_FAIR_GROUP_SCHED */
 
 	/*