sched: Discard some old bits

WAKEUP_RUNNING was an experiment, not sure why that ever ended up being
merged...

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

include/linux/sched.h

@@ -1152,8 +1152,6 @@ struct sched_entity {
 	u64			start_runtime;
 	u64			avg_wakeup;
 
-	u64			avg_running;
-
 #ifdef CONFIG_SCHEDSTATS
 	u64			wait_start;
 	u64			wait_max;

kernel/sched.c

@@ -2493,7 +2493,6 @@ static void __sched_fork(struct task_struct *p)
 	p->se.avg_overlap		= 0;
 	p->se.start_runtime		= 0;
 	p->se.avg_wakeup		= sysctl_sched_wakeup_granularity;
-	p->se.avg_running		= 0;
 
 #ifdef CONFIG_SCHEDSTATS
 	p->se.wait_start			= 0;
@@ -5379,13 +5378,14 @@ static inline void schedule_debug(struct task_struct *prev)
 #endif
 }
 
-static void put_prev_task(struct rq *rq, struct task_struct *p)
+static void put_prev_task(struct rq *rq, struct task_struct *prev)
 {
-	u64 runtime = p->se.sum_exec_runtime - p->se.prev_sum_exec_runtime;
+	if (prev->state == TASK_RUNNING) {
+		u64 runtime = prev->se.sum_exec_runtime;
 
-	update_avg(&p->se.avg_running, runtime);
+		runtime -= prev->se.prev_sum_exec_runtime;
+		runtime = min_t(u64, runtime, 2*sysctl_sched_migration_cost);
 
-	if (p->state == TASK_RUNNING) {
 		/*
 		 * In order to avoid avg_overlap growing stale when we are
 		 * indeed overlapping and hence not getting put to sleep, grow
@@ -5395,12 +5395,9 @@ static void put_prev_task(struct rq *rq, struct task_struct *p)
 		 * correlates to the amount of cache footprint a task can
 		 * build up.
 		 */
-		runtime = min_t(u64, runtime, 2*sysctl_sched_migration_cost);
-		update_avg(&p->se.avg_overlap, runtime);
-	} else {
-		update_avg(&p->se.avg_running, 0);
+		update_avg(&prev->se.avg_overlap, runtime);
 	}
-	p->sched_class->put_prev_task(rq, p);
+	prev->sched_class->put_prev_task(rq, prev);
 }
 
 /*

kernel/sched_debug.c

@@ -399,7 +399,6 @@ void proc_sched_show_task(struct task_struct *p, struct seq_file *m)
 	PN(se.sum_exec_runtime);
 	PN(se.avg_overlap);
 	PN(se.avg_wakeup);
-	PN(se.avg_running);
 
 	nr_switches = p->nvcsw + p->nivcsw;
 

kernel/sched_fair.c

@@ -1689,9 +1689,6 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int wake_
 			pse->avg_overlap < sysctl_sched_migration_cost)
 		goto preempt;
 
-	if (sched_feat(WAKEUP_RUNNING) && pse->avg_running < se->avg_running)
-		goto preempt;
-
 	if (!sched_feat(WAKEUP_PREEMPT))
 		return;
 

kernel/sched_features.h

@@ -53,11 +53,6 @@ SCHED_FEAT(WAKEUP_SYNC, 0)
  */
 SCHED_FEAT(WAKEUP_OVERLAP, 0)
 
-/*
- * Wakeup preemption towards tasks that run short
- */
-SCHED_FEAT(WAKEUP_RUNNING, 0)
-
 /*
  * Use the SYNC wakeup hint, pipes and the likes use this to indicate
  * the remote end is likely to consume the data we just wrote, and