sched: Make separate sched*.c translation units

Since once needs to do something at conferences and fixing compile
warnings doesn't actually require much if any attention I decided
to break up the sched.c #include "*.c" fest.

This further modularizes the scheduler code.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-x0fcd3mnp8f9c99grcpewmhi@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 542 insertions, 38 deletions

diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index a608593df243..cd3b64219d9f 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -23,6 +23,13 @@
 #include <linux/latencytop.h>
 #include <linux/sched.h>
 #include <linux/cpumask.h>
+#include <linux/slab.h>
+#include <linux/profile.h>
+#include <linux/interrupt.h>
+
+#include <trace/events/sched.h>
+
+#include "sched.h"
 
 /*
  * Targeted preemption latency for CPU-bound tasks:
@@ -103,7 +110,110 @@ unsigned int __read_mostly sysctl_sched_shares_window = 10000000UL;
 unsigned int sysctl_sched_cfs_bandwidth_slice = 5000UL;
 #endif
 
-static const struct sched_class fair_sched_class;
+/*
+ * Increase the granularity value when there are more CPUs,
+ * because with more CPUs the 'effective latency' as visible
+ * to users decreases. But the relationship is not linear,
+ * so pick a second-best guess by going with the log2 of the
+ * number of CPUs.
+ *
+ * This idea comes from the SD scheduler of Con Kolivas:
+ */
+static int get_update_sysctl_factor(void)
+{
+	unsigned int cpus = min_t(int, num_online_cpus(), 8);
+	unsigned int factor;
+
+	switch (sysctl_sched_tunable_scaling) {
+	case SCHED_TUNABLESCALING_NONE:
+		factor = 1;
+		break;
+	case SCHED_TUNABLESCALING_LINEAR:
+		factor = cpus;
+		break;
+	case SCHED_TUNABLESCALING_LOG:
+	default:
+		factor = 1 + ilog2(cpus);
+		break;
+	}
+
+	return factor;
+}
+
+static void update_sysctl(void)
+{
+	unsigned int factor = get_update_sysctl_factor();
+
+#define SET_SYSCTL(name) \
+	(sysctl_##name = (factor) * normalized_sysctl_##name)
+	SET_SYSCTL(sched_min_granularity);
+	SET_SYSCTL(sched_latency);
+	SET_SYSCTL(sched_wakeup_granularity);
+#undef SET_SYSCTL
+}
+
+void sched_init_granularity(void)
+{
+	update_sysctl();
+}
+
+#if BITS_PER_LONG == 32
+# define WMULT_CONST	(~0UL)
+#else
+# define WMULT_CONST	(1UL << 32)
+#endif
+
+#define WMULT_SHIFT	32
+
+/*
+ * Shift right and round:
+ */
+#define SRR(x, y) (((x) + (1UL << ((y) - 1))) >> (y))
+
+/*
+ * delta *= weight / lw
+ */
+static unsigned long
+calc_delta_mine(unsigned long delta_exec, unsigned long weight,
+		struct load_weight *lw)
+{
+	u64 tmp;
+
+	/*
+	 * weight can be less than 2^SCHED_LOAD_RESOLUTION for task group sched
+	 * entities since MIN_SHARES = 2. Treat weight as 1 if less than
+	 * 2^SCHED_LOAD_RESOLUTION.
+	 */
+	if (likely(weight > (1UL << SCHED_LOAD_RESOLUTION)))
+		tmp = (u64)delta_exec * scale_load_down(weight);
+	else
+		tmp = (u64)delta_exec;
+
+	if (!lw->inv_weight) {
+		unsigned long w = scale_load_down(lw->weight);
+
+		if (BITS_PER_LONG > 32 && unlikely(w >= WMULT_CONST))
+			lw->inv_weight = 1;
+		else if (unlikely(!w))
+			lw->inv_weight = WMULT_CONST;
+		else
+			lw->inv_weight = WMULT_CONST / w;
+	}
+
+	/*
+	 * Check whether we'd overflow the 64-bit multiplication:
+	 */
+	if (unlikely(tmp > WMULT_CONST))
+		tmp = SRR(SRR(tmp, WMULT_SHIFT/2) * lw->inv_weight,
+			WMULT_SHIFT/2);
+	else
+		tmp = SRR(tmp * lw->inv_weight, WMULT_SHIFT);
+
+	return (unsigned long)min(tmp, (u64)(unsigned long)LONG_MAX);
+}
+
+
+const struct sched_class fair_sched_class;
 
 /**************************************************************
  * CFS operations on generic schedulable entities:
@@ -413,7 +523,7 @@ static void __dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
 	rb_erase(&se->run_node, &cfs_rq->tasks_timeline);
 }
 
-static struct sched_entity *__pick_first_entity(struct cfs_rq *cfs_rq)
+struct sched_entity *__pick_first_entity(struct cfs_rq *cfs_rq)
 {
 	struct rb_node *left = cfs_rq->rb_leftmost;
 
@@ -434,7 +544,7 @@ static struct sched_entity *__pick_next_entity(struct sched_entity *se)
 }
 
 #ifdef CONFIG_SCHED_DEBUG
-static struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq)
+struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq)
 {
 	struct rb_node *last = rb_last(&cfs_rq->tasks_timeline);
 
@@ -684,7 +794,7 @@ account_entity_enqueue(struct cfs_rq *cfs_rq, struct sched_entity *se)
 {
 	update_load_add(&cfs_rq->load, se->load.weight);
 	if (!parent_entity(se))
-		inc_cpu_load(rq_of(cfs_rq), se->load.weight);
+		update_load_add(&rq_of(cfs_rq)->load, se->load.weight);
 	if (entity_is_task(se)) {
 		add_cfs_task_weight(cfs_rq, se->load.weight);
 		list_add(&se->group_node, &cfs_rq->tasks);
@@ -697,7 +807,7 @@ account_entity_dequeue(struct cfs_rq *cfs_rq, struct sched_entity *se)
 {
 	update_load_sub(&cfs_rq->load, se->load.weight);
 	if (!parent_entity(se))
-		dec_cpu_load(rq_of(cfs_rq), se->load.weight);
+		update_load_sub(&rq_of(cfs_rq)->load, se->load.weight);
 	if (entity_is_task(se)) {
 		add_cfs_task_weight(cfs_rq, -se->load.weight);
 		list_del_init(&se->group_node);
@@ -1287,6 +1397,32 @@ entity_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr, int queued)
  */
 
 #ifdef CONFIG_CFS_BANDWIDTH
+
+#ifdef HAVE_JUMP_LABEL
+static struct jump_label_key __cfs_bandwidth_used;
+
+static inline bool cfs_bandwidth_used(void)
+{
+	return static_branch(&__cfs_bandwidth_used);
+}
+
+void account_cfs_bandwidth_used(int enabled, int was_enabled)
+{
+	/* only need to count groups transitioning between enabled/!enabled */
+	if (enabled && !was_enabled)
+		jump_label_inc(&__cfs_bandwidth_used);
+	else if (!enabled && was_enabled)
+		jump_label_dec(&__cfs_bandwidth_used);
+}
+#else /* HAVE_JUMP_LABEL */
+static bool cfs_bandwidth_used(void)
+{
+	return true;
+}
+
+void account_cfs_bandwidth_used(int enabled, int was_enabled) {}
+#endif /* HAVE_JUMP_LABEL */
+
 /*
  * default period for cfs group bandwidth.
  * default: 0.1s, units: nanoseconds
@@ -1308,7 +1444,7 @@ static inline u64 sched_cfs_bandwidth_slice(void)
  *
  * requires cfs_b->lock
  */
-static void __refill_cfs_bandwidth_runtime(struct cfs_bandwidth *cfs_b)
+void __refill_cfs_bandwidth_runtime(struct cfs_bandwidth *cfs_b)
 {
 	u64 now;
 
@@ -1320,6 +1456,11 @@ static void __refill_cfs_bandwidth_runtime(struct cfs_bandwidth *cfs_b)
 	cfs_b->runtime_expires = now + ktime_to_ns(cfs_b->period);
 }
 
+static inline struct cfs_bandwidth *tg_cfs_bandwidth(struct task_group *tg)
+{
+	return &tg->cfs_bandwidth;
+}
+
 /* returns 0 on failure to allocate runtime */
 static int assign_cfs_rq_runtime(struct cfs_rq *cfs_rq)
 {
@@ -1530,7 +1671,7 @@ static void throttle_cfs_rq(struct cfs_rq *cfs_rq)
 	raw_spin_unlock(&cfs_b->lock);
 }
 
-static void unthrottle_cfs_rq(struct cfs_rq *cfs_rq)
+void unthrottle_cfs_rq(struct cfs_rq *cfs_rq)
 {
 	struct rq *rq = rq_of(cfs_rq);
 	struct cfs_bandwidth *cfs_b = tg_cfs_bandwidth(cfs_rq->tg);
@@ -1839,7 +1980,112 @@ static void check_cfs_rq_runtime(struct cfs_rq *cfs_rq)
 
 	throttle_cfs_rq(cfs_rq);
 }
-#else
+
+static inline u64 default_cfs_period(void);
+static int do_sched_cfs_period_timer(struct cfs_bandwidth *cfs_b, int overrun);
+static void do_sched_cfs_slack_timer(struct cfs_bandwidth *cfs_b);
+
+static enum hrtimer_restart sched_cfs_slack_timer(struct hrtimer *timer)
+{
+	struct cfs_bandwidth *cfs_b =
+		container_of(timer, struct cfs_bandwidth, slack_timer);
+	do_sched_cfs_slack_timer(cfs_b);
+
+	return HRTIMER_NORESTART;
+}
+
+static enum hrtimer_restart sched_cfs_period_timer(struct hrtimer *timer)
+{
+	struct cfs_bandwidth *cfs_b =
+		container_of(timer, struct cfs_bandwidth, period_timer);
+	ktime_t now;
+	int overrun;
+	int idle = 0;
+
+	for (;;) {
+		now = hrtimer_cb_get_time(timer);
+		overrun = hrtimer_forward(timer, now, cfs_b->period);
+
+		if (!overrun)
+			break;
+
+		idle = do_sched_cfs_period_timer(cfs_b, overrun);
+	}
+
+	return idle ? HRTIMER_NORESTART : HRTIMER_RESTART;
+}
+
+void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b)
+{
+	raw_spin_lock_init(&cfs_b->lock);
+	cfs_b->runtime = 0;
+	cfs_b->quota = RUNTIME_INF;
+	cfs_b->period = ns_to_ktime(default_cfs_period());
+
+	INIT_LIST_HEAD(&cfs_b->throttled_cfs_rq);
+	hrtimer_init(&cfs_b->period_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+	cfs_b->period_timer.function = sched_cfs_period_timer;
+	hrtimer_init(&cfs_b->slack_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+	cfs_b->slack_timer.function = sched_cfs_slack_timer;
+}
+
+static void init_cfs_rq_runtime(struct cfs_rq *cfs_rq)
+{
+	cfs_rq->runtime_enabled = 0;
+	INIT_LIST_HEAD(&cfs_rq->throttled_list);
+}
+
+/* requires cfs_b->lock, may release to reprogram timer */
+void __start_cfs_bandwidth(struct cfs_bandwidth *cfs_b)
+{
+	/*
+	 * The timer may be active because we're trying to set a new bandwidth
+	 * period or because we're racing with the tear-down path
+	 * (timer_active==0 becomes visible before the hrtimer call-back
+	 * terminates).  In either case we ensure that it's re-programmed
+	 */
+	while (unlikely(hrtimer_active(&cfs_b->period_timer))) {
+		raw_spin_unlock(&cfs_b->lock);
+		/* ensure cfs_b->lock is available while we wait */
+		hrtimer_cancel(&cfs_b->period_timer);
+
+		raw_spin_lock(&cfs_b->lock);
+		/* if someone else restarted the timer then we're done */
+		if (cfs_b->timer_active)
+			return;
+	}
+
+	cfs_b->timer_active = 1;
+	start_bandwidth_timer(&cfs_b->period_timer, cfs_b->period);
+}
+
+static void destroy_cfs_bandwidth(struct cfs_bandwidth *cfs_b)
+{
+	hrtimer_cancel(&cfs_b->period_timer);
+	hrtimer_cancel(&cfs_b->slack_timer);
+}
+
+void unthrottle_offline_cfs_rqs(struct rq *rq)
+{
+	struct cfs_rq *cfs_rq;
+
+	for_each_leaf_cfs_rq(rq, cfs_rq) {
+		struct cfs_bandwidth *cfs_b = tg_cfs_bandwidth(cfs_rq->tg);
+
+		if (!cfs_rq->runtime_enabled)
+			continue;
+
+		/*
+		 * clock_task is not advancing so we just need to make sure
+		 * there's some valid quota amount
+		 */
+		cfs_rq->runtime_remaining = cfs_b->quota;
+		if (cfs_rq_throttled(cfs_rq))
+			unthrottle_cfs_rq(cfs_rq);
+	}
+}
+
+#else /* CONFIG_CFS_BANDWIDTH */
 static void account_cfs_rq_runtime(struct cfs_rq *cfs_rq,
 				     unsigned long delta_exec) {}
 static void check_cfs_rq_runtime(struct cfs_rq *cfs_rq) {}
@@ -1861,8 +2107,22 @@ static inline int throttled_lb_pair(struct task_group *tg,
 {
 	return 0;
 }
+
+void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b) {}
+
+#ifdef CONFIG_FAIR_GROUP_SCHED
+static void init_cfs_rq_runtime(struct cfs_rq *cfs_rq) {}
 #endif
 
+static inline struct cfs_bandwidth *tg_cfs_bandwidth(struct task_group *tg)
+{
+	return NULL;
+}
+static inline void destroy_cfs_bandwidth(struct cfs_bandwidth *cfs_b) {}
+void unthrottle_offline_cfs_rqs(struct rq *rq) {}
+
+#endif /* CONFIG_CFS_BANDWIDTH */
+
 /**************************************************
  * CFS operations on tasks:
  */
@@ -2029,6 +2289,61 @@ static void dequeue_task_fair(struct rq *rq, struct task_struct *p, int flags)
 }
 
 #ifdef CONFIG_SMP
+/* Used instead of source_load when we know the type == 0 */
+static unsigned long weighted_cpuload(const int cpu)
+{
+	return cpu_rq(cpu)->load.weight;
+}
+
+/*
+ * Return a low guess at the load of a migration-source cpu weighted
+ * according to the scheduling class and "nice" value.
+ *
+ * We want to under-estimate the load of migration sources, to
+ * balance conservatively.
+ */
+static unsigned long source_load(int cpu, int type)
+{
+	struct rq *rq = cpu_rq(cpu);
+	unsigned long total = weighted_cpuload(cpu);
+
+	if (type == 0 || !sched_feat(LB_BIAS))
+		return total;
+
+	return min(rq->cpu_load[type-1], total);
+}
+
+/*
+ * Return a high guess at the load of a migration-target cpu weighted
+ * according to the scheduling class and "nice" value.
+ */
+static unsigned long target_load(int cpu, int type)
+{
+	struct rq *rq = cpu_rq(cpu);
+	unsigned long total = weighted_cpuload(cpu);
+
+	if (type == 0 || !sched_feat(LB_BIAS))
+		return total;
+
+	return max(rq->cpu_load[type-1], total);
+}
+
+static unsigned long power_of(int cpu)
+{
+	return cpu_rq(cpu)->cpu_power;
+}
+
+static unsigned long cpu_avg_load_per_task(int cpu)
+{
+	struct rq *rq = cpu_rq(cpu);
+	unsigned long nr_running = ACCESS_ONCE(rq->nr_running);
+
+	if (nr_running)
+		return rq->load.weight / nr_running;
+
+	return 0;
+}
+
 
 static void task_waking_fair(struct task_struct *p)
 {
@@ -2783,6 +3098,38 @@ static void pull_task(struct rq *src_rq, struct task_struct *p,
 }
 
 /*
+ * Is this task likely cache-hot:
+ */
+static int
+task_hot(struct task_struct *p, u64 now, struct sched_domain *sd)
+{
+	s64 delta;
+
+	if (p->sched_class != &fair_sched_class)
+		return 0;
+
+	if (unlikely(p->policy == SCHED_IDLE))
+		return 0;
+
+	/*
+	 * Buddy candidates are cache hot:
+	 */
+	if (sched_feat(CACHE_HOT_BUDDY) && this_rq()->nr_running &&
+			(&p->se == cfs_rq_of(&p->se)->next ||
+			 &p->se == cfs_rq_of(&p->se)->last))
+		return 1;
+
+	if (sysctl_sched_migration_cost == -1)
+		return 1;
+	if (sysctl_sched_migration_cost == 0)
+		return 0;
+
+	delta = now - p->se.exec_start;
+
+	return delta < (s64)sysctl_sched_migration_cost;
+}
+
+/*
  * can_migrate_task - may task p from runqueue rq be migrated to this_cpu?
  */
 static
@@ -3162,15 +3509,6 @@ struct sg_lb_stats {
 };
 
 /**
- * group_first_cpu - Returns the first cpu in the cpumask of a sched_group.
- * @group: The group whose first cpu is to be returned.
- */
-static inline unsigned int group_first_cpu(struct sched_group *group)
-{
-	return cpumask_first(sched_group_cpus(group));
-}
-
-/**
  * get_sd_load_idx - Obtain the load index for a given sched domain.
  * @sd: The sched_domain whose load_idx is to be obtained.
  * @idle: The Idle status of the CPU for whose sd load_icx is obtained.
@@ -3419,7 +3757,7 @@ static void update_cpu_power(struct sched_domain *sd, int cpu)
 	sdg->sgp->power = power;
 }
 
-static void update_group_power(struct sched_domain *sd, int cpu)
+void update_group_power(struct sched_domain *sd, int cpu)
 {
 	struct sched_domain *child = sd->child;
 	struct sched_group *group, *sdg = sd->groups;
@@ -3685,11 +4023,6 @@ static inline void update_sd_lb_stats(struct sched_domain *sd, int this_cpu,
 	} while (sg != sd->groups);
 }
 
-int __weak arch_sd_sibling_asym_packing(void)
-{
-       return 0*SD_ASYM_PACKING;
-}
-
 /**
  * check_asym_packing - Check to see if the group is packed into the
  *			sched doman.
@@ -4053,7 +4386,7 @@ find_busiest_queue(struct sched_domain *sd, struct sched_group *group,
 #define MAX_PINNED_INTERVAL	512
 
 /* Working cpumask for load_balance and load_balance_newidle. */
-static DEFINE_PER_CPU(cpumask_var_t, load_balance_tmpmask);
+DEFINE_PER_CPU(cpumask_var_t, load_balance_tmpmask);
 
 static int need_active_balance(struct sched_domain *sd, int idle,
 			       int busiest_cpu, int this_cpu)
@@ -4256,7 +4589,7 @@ out:
  * idle_balance is called by schedule() if this_cpu is about to become
  * idle. Attempts to pull tasks from other CPUs.
  */
-static void idle_balance(int this_cpu, struct rq *this_rq)
+void idle_balance(int this_cpu, struct rq *this_rq)
 {
 	struct sched_domain *sd;
 	int pulled_task = 0;
@@ -4631,7 +4964,7 @@ static unsigned long __read_mostly max_load_balance_interval = HZ/10;
  * Scale the max load_balance interval with the number of CPUs in the system.
  * This trades load-balance latency on larger machines for less cross talk.
  */
-static void update_max_interval(void)
+void update_max_interval(void)
 {
 	max_load_balance_interval = HZ*num_online_cpus()/10;
 }
@@ -4833,7 +5166,7 @@ static inline int on_null_domain(int cpu)
 /*
  * Trigger the SCHED_SOFTIRQ if it is time to do periodic load balancing.
  */
-static inline void trigger_load_balance(struct rq *rq, int cpu)
+void trigger_load_balance(struct rq *rq, int cpu)
 {
 	/* Don't need to rebalance while attached to NULL domain */
 	if (time_after_eq(jiffies, rq->next_balance) &&
@@ -4855,15 +5188,6 @@ static void rq_offline_fair(struct rq *rq)
 	update_sysctl();
 }
 
-#else	/* CONFIG_SMP */
-
-/*
- * on UP we do not need to balance between CPUs:
- */
-static inline void idle_balance(int cpu, struct rq *rq)
-{
-}
-
 #endif /* CONFIG_SMP */
 
 /*
@@ -5006,6 +5330,16 @@ static void set_curr_task_fair(struct rq *rq)
 	}
 }
 
+void init_cfs_rq(struct cfs_rq *cfs_rq)
+{
+	cfs_rq->tasks_timeline = RB_ROOT;
+	INIT_LIST_HEAD(&cfs_rq->tasks);
+	cfs_rq->min_vruntime = (u64)(-(1LL << 20));
+#ifndef CONFIG_64BIT
+	cfs_rq->min_vruntime_copy = cfs_rq->min_vruntime;
+#endif
+}
+
 #ifdef CONFIG_FAIR_GROUP_SCHED
 static void task_move_group_fair(struct task_struct *p, int on_rq)
 {
@@ -5028,7 +5362,161 @@ static void task_move_group_fair(struct task_struct *p, int on_rq)
 	if (!on_rq)
 		p->se.vruntime += cfs_rq_of(&p->se)->min_vruntime;
 }
+
+void free_fair_sched_group(struct task_group *tg)
+{
+	int i;
+
+	destroy_cfs_bandwidth(tg_cfs_bandwidth(tg));
+
+	for_each_possible_cpu(i) {
+		if (tg->cfs_rq)
+			kfree(tg->cfs_rq[i]);
+		if (tg->se)
+			kfree(tg->se[i]);
+	}
+
+	kfree(tg->cfs_rq);
+	kfree(tg->se);
+}
+
+int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent)
+{
+	struct cfs_rq *cfs_rq;
+	struct sched_entity *se;
+	int i;
+
+	tg->cfs_rq = kzalloc(sizeof(cfs_rq) * nr_cpu_ids, GFP_KERNEL);
+	if (!tg->cfs_rq)
+		goto err;
+	tg->se = kzalloc(sizeof(se) * nr_cpu_ids, GFP_KERNEL);
+	if (!tg->se)
+		goto err;
+
+	tg->shares = NICE_0_LOAD;
+
+	init_cfs_bandwidth(tg_cfs_bandwidth(tg));
+
+	for_each_possible_cpu(i) {
+		cfs_rq = kzalloc_node(sizeof(struct cfs_rq),
+				      GFP_KERNEL, cpu_to_node(i));
+		if (!cfs_rq)
+			goto err;
+
+		se = kzalloc_node(sizeof(struct sched_entity),
+				  GFP_KERNEL, cpu_to_node(i));
+		if (!se)
+			goto err_free_rq;
+
+		init_cfs_rq(cfs_rq);
+		init_tg_cfs_entry(tg, cfs_rq, se, i, parent->se[i]);
+	}
+
+	return 1;
+
+err_free_rq:
+	kfree(cfs_rq);
+err:
+	return 0;
+}
+
+void unregister_fair_sched_group(struct task_group *tg, int cpu)
+{
+	struct rq *rq = cpu_rq(cpu);
+	unsigned long flags;
+
+	/*
+	* Only empty task groups can be destroyed; so we can speculatively
+	* check on_list without danger of it being re-added.
+	*/
+	if (!tg->cfs_rq[cpu]->on_list)
+		return;
+
+	raw_spin_lock_irqsave(&rq->lock, flags);
+	list_del_leaf_cfs_rq(tg->cfs_rq[cpu]);
+	raw_spin_unlock_irqrestore(&rq->lock, flags);
+}
+
+void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq,
+			struct sched_entity *se, int cpu,
+			struct sched_entity *parent)
+{
+	struct rq *rq = cpu_rq(cpu);
+
+	cfs_rq->tg = tg;
+	cfs_rq->rq = rq;
+#ifdef CONFIG_SMP
+	/* allow initial update_cfs_load() to truncate */
+	cfs_rq->load_stamp = 1;
 #endif
+	init_cfs_rq_runtime(cfs_rq);
+
+	tg->cfs_rq[cpu] = cfs_rq;
+	tg->se[cpu] = se;
+
+	/* se could be NULL for root_task_group */
+	if (!se)
+		return;
+
+	if (!parent)
+		se->cfs_rq = &rq->cfs;
+	else
+		se->cfs_rq = parent->my_q;
+
+	se->my_q = cfs_rq;
+	update_load_set(&se->load, 0);
+	se->parent = parent;
+}
+
+static DEFINE_MUTEX(shares_mutex);
+
+int sched_group_set_shares(struct task_group *tg, unsigned long shares)
+{
+	int i;
+	unsigned long flags;
+
+	/*
+	 * We can't change the weight of the root cgroup.
+	 */
+	if (!tg->se[0])
+		return -EINVAL;
+
+	shares = clamp(shares, scale_load(MIN_SHARES), scale_load(MAX_SHARES));
+
+	mutex_lock(&shares_mutex);
+	if (tg->shares == shares)
+		goto done;
+
+	tg->shares = shares;
+	for_each_possible_cpu(i) {
+		struct rq *rq = cpu_rq(i);
+		struct sched_entity *se;
+
+		se = tg->se[i];
+		/* Propagate contribution to hierarchy */
+		raw_spin_lock_irqsave(&rq->lock, flags);
+		for_each_sched_entity(se)
+			update_cfs_shares(group_cfs_rq(se));
+		raw_spin_unlock_irqrestore(&rq->lock, flags);
+	}
+
+done:
+	mutex_unlock(&shares_mutex);
+	return 0;
+}
+#else /* CONFIG_FAIR_GROUP_SCHED */
+
+void free_fair_sched_group(struct task_group *tg) { }
+
+int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent)
+{
+	return 1;
+}
+
+void unregister_fair_sched_group(struct task_group *tg, int cpu) { }
+
+#endif /* CONFIG_FAIR_GROUP_SCHED */
+
 
 static unsigned int get_rr_interval_fair(struct rq *rq, struct task_struct *task)
 {
@@ -5048,7 +5536,7 @@ static unsigned int get_rr_interval_fair(struct rq *rq, struct task_struct *task
 /*
  * All the scheduling class methods:
  */
-static const struct sched_class fair_sched_class = {
+const struct sched_class fair_sched_class = {
 	.next			= &idle_sched_class,
 	.enqueue_task		= enqueue_task_fair,
 	.dequeue_task		= dequeue_task_fair,
@@ -5085,7 +5573,7 @@ static const struct sched_class fair_sched_class = {
 };
 
 #ifdef CONFIG_SCHED_DEBUG
-static void print_cfs_stats(struct seq_file *m, int cpu)
+void print_cfs_stats(struct seq_file *m, int cpu)
 {
 	struct cfs_rq *cfs_rq;
 
@@ -5095,3 +5583,19 @@ static void print_cfs_stats(struct seq_file *m, int cpu)
 	rcu_read_unlock();
 }
 #endif
+
+__init void init_sched_fair_class(void)
+{
+#ifdef CONFIG_SMP
+	open_softirq(SCHED_SOFTIRQ, run_rebalance_domains);
+
+#ifdef CONFIG_NO_HZ
+	zalloc_cpumask_var(&nohz.idle_cpus_mask, GFP_NOWAIT);
+	alloc_cpumask_var(&nohz.grp_idle_mask, GFP_NOWAIT);
+	atomic_set(&nohz.load_balancer, nr_cpu_ids);
+	atomic_set(&nohz.first_pick_cpu, nr_cpu_ids);
+	atomic_set(&nohz.second_pick_cpu, nr_cpu_ids);
+#endif
+#endif /* SMP */
+
+}