1 files changed, 77 insertions, 49 deletions

diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index c62ebae65cf0..0c26e2df450e 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -699,7 +699,8 @@ account_entity_dequeue(struct cfs_rq *cfs_rq, struct sched_entity *se)
 	cfs_rq->nr_running--;
 }
 
-#if defined CONFIG_SMP && defined CONFIG_FAIR_GROUP_SCHED
+#ifdef CONFIG_FAIR_GROUP_SCHED
+# ifdef CONFIG_SMP
 static void update_cfs_rq_load_contribution(struct cfs_rq *cfs_rq,
 					    int global_update)
 {
@@ -721,10 +722,10 @@ static void update_cfs_load(struct cfs_rq *cfs_rq, int global_update)
 	u64 now, delta;
 	unsigned long load = cfs_rq->load.weight;
 
-	if (!cfs_rq)
+	if (cfs_rq->tg == &root_task_group)
 		return;
 
-	now = rq_of(cfs_rq)->clock;
+	now = rq_of(cfs_rq)->clock_task;
 	delta = now - cfs_rq->load_stamp;
 
 	/* truncate load history at 4 idle periods */
@@ -762,6 +763,51 @@ static void update_cfs_load(struct cfs_rq *cfs_rq, int global_update)
 		list_del_leaf_cfs_rq(cfs_rq);
 }
 
+static long calc_cfs_shares(struct cfs_rq *cfs_rq, struct task_group *tg,
+				long weight_delta)
+{
+	long load_weight, load, shares;
+
+	load = cfs_rq->load.weight + weight_delta;
+
+	load_weight = atomic_read(&tg->load_weight);
+	load_weight -= cfs_rq->load_contribution;
+	load_weight += load;
+
+	shares = (tg->shares * load);
+	if (load_weight)
+		shares /= load_weight;
+
+	if (shares < MIN_SHARES)
+		shares = MIN_SHARES;
+	if (shares > tg->shares)
+		shares = tg->shares;
+
+	return shares;
+}
+
+static void update_entity_shares_tick(struct cfs_rq *cfs_rq)
+{
+	if (cfs_rq->load_unacc_exec_time > sysctl_sched_shares_window) {
+		update_cfs_load(cfs_rq, 0);
+		update_cfs_shares(cfs_rq, 0);
+	}
+}
+# else /* CONFIG_SMP */
+static void update_cfs_load(struct cfs_rq *cfs_rq, int global_update)
+{
+}
+
+static inline long calc_cfs_shares(struct cfs_rq *cfs_rq, struct task_group *tg,
+				long weight_delta)
+{
+	return tg->shares;
+}
+
+static inline void update_entity_shares_tick(struct cfs_rq *cfs_rq)
+{
+}
+# endif /* CONFIG_SMP */
 static void reweight_entity(struct cfs_rq *cfs_rq, struct sched_entity *se,
 			    unsigned long weight)
 {
@@ -782,41 +828,20 @@ static void update_cfs_shares(struct cfs_rq *cfs_rq, long weight_delta)
 {
 	struct task_group *tg;
 	struct sched_entity *se;
-	long load_weight, load, shares;
-
-	if (!cfs_rq)
-		return;
+	long shares;
 
 	tg = cfs_rq->tg;
 	se = tg->se[cpu_of(rq_of(cfs_rq))];
 	if (!se)
 		return;
-
-	load = cfs_rq->load.weight + weight_delta;
-
-	load_weight = atomic_read(&tg->load_weight);
-	load_weight -= cfs_rq->load_contribution;
-	load_weight += load;
-
-	shares = (tg->shares * load);
-	if (load_weight)
-		shares /= load_weight;
-
-	if (shares < MIN_SHARES)
-		shares = MIN_SHARES;
-	if (shares > tg->shares)
-		shares = tg->shares;
+#ifndef CONFIG_SMP
+	if (likely(se->load.weight == tg->shares))
+		return;
+#endif
+	shares = calc_cfs_shares(cfs_rq, tg, weight_delta);
 
 	reweight_entity(cfs_rq_of(se), se, shares);
 }
-
-static void update_entity_shares_tick(struct cfs_rq *cfs_rq)
-{
-	if (cfs_rq->load_unacc_exec_time > sysctl_sched_shares_window) {
-		update_cfs_load(cfs_rq, 0);
-		update_cfs_shares(cfs_rq, 0);
-	}
-}
 #else /* CONFIG_FAIR_GROUP_SCHED */
 static void update_cfs_load(struct cfs_rq *cfs_rq, int global_update)
 {
@@ -1062,6 +1087,9 @@ check_preempt_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr)
 		struct sched_entity *se = __pick_next_entity(cfs_rq);
 		s64 delta = curr->vruntime - se->vruntime;
 
+		if (delta < 0)
+			return;
+
 		if (delta > ideal_runtime)
 			resched_task(rq_of(cfs_rq)->curr);
 	}
@@ -1362,27 +1390,27 @@ static long effective_load(struct task_group *tg, int cpu, long wl, long wg)
 		return wl;
 
 	for_each_sched_entity(se) {
-		long S, rw, s, a, b;
+		long lw, w;
 
-		S = se->my_q->tg->shares;
-		s = se->load.weight;
-		rw = se->my_q->load.weight;
+		tg = se->my_q->tg;
+		w = se->my_q->load.weight;
 
-		a = S*(rw + wl);
-		b = S*rw + s*wg;
+		/* use this cpu's instantaneous contribution */
+		lw = atomic_read(&tg->load_weight);
+		lw -= se->my_q->load_contribution;
+		lw += w + wg;
 
-		wl = s*(a-b);
+		wl += w;
 
-		if (likely(b))
-			wl /= b;
+		if (lw > 0 && wl < lw)
+			wl = (wl * tg->shares) / lw;
+		else
+			wl = tg->shares;
 
-		/*
-		 * Assume the group is already running and will
-		 * thus already be accounted for in the weight.
-		 *
-		 * That is, moving shares between CPUs, does not
-		 * alter the group weight.
-		 */
+		/* zero point is MIN_SHARES */
+		if (wl < MIN_SHARES)
+			wl = MIN_SHARES;
+		wl -= se->load.weight;
 		wg = 0;
 	}
 
@@ -1401,7 +1429,7 @@ static inline unsigned long effective_load(struct task_group *tg, int cpu,
 
 static int wake_affine(struct sched_domain *sd, struct task_struct *p, int sync)
 {
-	unsigned long this_load, load;
+	s64 this_load, load;
 	int idx, this_cpu, prev_cpu;
 	unsigned long tl_per_task;
 	struct task_group *tg;
@@ -1440,8 +1468,8 @@ static int wake_affine(struct sched_domain *sd, struct task_struct *p, int sync)
 	 * Otherwise check if either cpus are near enough in load to allow this
 	 * task to be woken on this_cpu.
 	 */
-	if (this_load) {
-		unsigned long this_eff_load, prev_eff_load;
+	if (this_load > 0) {
+		s64 this_eff_load, prev_eff_load;
 
 		this_eff_load = 100;
 		this_eff_load *= power_of(prev_cpu);