sched: undo some of the recent changes

undo some of the recent changes that are not needed after all,
such as last_min_vruntime.

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

include/linux/sched.h

@@ -908,7 +908,6 @@ struct sched_entity {
 	u64			sum_exec_runtime;
 	u64			vruntime;
 	u64			prev_sum_exec_runtime;
-	u64			last_min_vruntime;
 
 #ifdef CONFIG_SCHEDSTATS
 	u64			wait_start;

kernel/sched.c

@@ -1616,7 +1616,6 @@ static void __sched_fork(struct task_struct *p)
 	p->se.exec_start		= 0;
 	p->se.sum_exec_runtime		= 0;
 	p->se.prev_sum_exec_runtime	= 0;
-	p->se.last_min_vruntime		= 0;
 
 #ifdef CONFIG_SCHEDSTATS
 	p->se.wait_start		= 0;

kernel/sched_fair.c

@@ -480,14 +480,9 @@ place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial)
 		vruntime += __sched_vslice(cfs_rq->nr_running + 1);
 
 	if (!initial) {
-		if (sched_feat(NEW_FAIR_SLEEPERS)) {
-			s64 latency = cfs_rq->min_vruntime - se->vruntime;
-			if (latency < 0 || !cfs_rq->nr_running)
-				latency = 0;
-			else
-				latency = min_t(s64, latency, sysctl_sched_latency);
-			vruntime -= latency;
-		}
+		if (sched_feat(NEW_FAIR_SLEEPERS))
+			vruntime -= sysctl_sched_latency;
+
 		vruntime = max(vruntime, se->vruntime);
 	}
 
@@ -531,8 +526,6 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int sleep)
 				se->block_start = rq_of(cfs_rq)->clock;
 		}
 #endif
-		/* se->vruntime = entity_key(cfs_rq, se); */
-		se->last_min_vruntime = cfs_rq->min_vruntime;
 	}
 
 	if (se != cfs_rq->curr)