[PATCH v6 10/11] sched: remove rt_avg code

[Vincent Guittot]

rt_avg is no more used anywhere so we can remove all related code

Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Signed-off-by: Vincent Guittot <vincent.guittot@xxxxxxxxxx>
---
 kernel/sched/core.c  | 26 --------------------------
 kernel/sched/fair.c  |  2 --
 kernel/sched/sched.h | 17 -----------------
 3 files changed, 45 deletions(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index ab58288..213d277 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -650,23 +650,6 @@ bool sched_can_stop_tick(struct rq *rq)
 	return true;
 }
 #endif /* CONFIG_NO_HZ_FULL */
-
-void sched_avg_update(struct rq *rq)
-{
-	s64 period = sched_avg_period();
-
-	while ((s64)(rq_clock(rq) - rq->age_stamp) > period) {
-		/*
-		 * Inline assembly required to prevent the compiler
-		 * optimising this loop into a divmod call.
-		 * See __iter_div_u64_rem() for another example of this.
-		 */
-		asm("" : "+rm" (rq->age_stamp));
-		rq->age_stamp += period;
-		rq->rt_avg /= 2;
-	}
-}
-
 #endif /* CONFIG_SMP */
 
 #if defined(CONFIG_RT_GROUP_SCHED) || (defined(CONFIG_FAIR_GROUP_SCHED) && \
@@ -5710,13 +5693,6 @@ void set_rq_offline(struct rq *rq)
 	}
 }
 
-static void set_cpu_rq_start_time(unsigned int cpu)
-{
-	struct rq *rq = cpu_rq(cpu);
-
-	rq->age_stamp = sched_clock_cpu(cpu);
-}
-
 /*
  * used to mark begin/end of suspend/resume:
  */
@@ -5834,7 +5810,6 @@ static void sched_rq_cpu_starting(unsigned int cpu)
 
 int sched_cpu_starting(unsigned int cpu)
 {
-	set_cpu_rq_start_time(cpu);
 	sched_rq_cpu_starting(cpu);
 	sched_tick_start(cpu);
 	return 0;
@@ -6102,7 +6077,6 @@ void __init sched_init(void)
 
 #ifdef CONFIG_SMP
 	idle_thread_set_boot_cpu();
-	set_cpu_rq_start_time(smp_processor_id());
 #endif
 	init_sched_fair_class();
 
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index fefd71b..3594692 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -5323,8 +5323,6 @@ static void cpu_load_update(struct rq *this_rq, unsigned long this_load,
 
 		this_rq->cpu_load[i] = (old_load * (scale - 1) + new_load) >> i;
 	}
-
-	sched_avg_update(this_rq);
 }
 
 /* Used instead of source_load when we know the type == 0 */
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 873b567..1faab06 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -846,8 +846,6 @@ struct rq {
 
 	struct list_head cfs_tasks;
 
-	u64			rt_avg;
-	u64			age_stamp;
 	struct sched_avg	avg_rt;
 	struct sched_avg	avg_dl;
 #if defined(CONFIG_IRQ_TIME_ACCOUNTING) || defined(CONFIG_PARAVIRT_TIME_ACCOUNTING)
@@ -1712,11 +1710,6 @@ extern const_debug unsigned int sysctl_sched_time_avg;
 extern const_debug unsigned int sysctl_sched_nr_migrate;
 extern const_debug unsigned int sysctl_sched_migration_cost;
 
-static inline u64 sched_avg_period(void)
-{
-	return (u64)sysctl_sched_time_avg * NSEC_PER_MSEC / 2;
-}
-
 #ifdef CONFIG_SCHED_HRTICK
 
 /*
@@ -1753,8 +1746,6 @@ unsigned long arch_scale_freq_capacity(int cpu)
 #endif
 
 #ifdef CONFIG_SMP
-extern void sched_avg_update(struct rq *rq);
-
 #ifndef arch_scale_cpu_capacity
 static __always_inline
 unsigned long arch_scale_cpu_capacity(struct sched_domain *sd, int cpu)
@@ -1765,12 +1756,6 @@ unsigned long arch_scale_cpu_capacity(struct sched_domain *sd, int cpu)
 	return SCHED_CAPACITY_SCALE;
 }
 #endif
-
-static inline void sched_rt_avg_update(struct rq *rq, u64 rt_delta)
-{
-	rq->rt_avg += rt_delta * arch_scale_freq_capacity(cpu_of(rq));
-	sched_avg_update(rq);
-}
 #else
 #ifndef arch_scale_cpu_capacity
 static __always_inline
@@ -1779,8 +1764,6 @@ unsigned long arch_scale_cpu_capacity(void __always_unused *sd, int cpu)
 	return SCHED_CAPACITY_SCALE;
 }
 #endif
-static inline void sched_rt_avg_update(struct rq *rq, u64 rt_delta) { }
-static inline void sched_avg_update(struct rq *rq) { }
 #endif
 
 struct rq *__task_rq_lock(struct task_struct *p, struct rq_flags *rf)
-- 
2.7.4