BLD_fixed.3.3.7.patch

diff -Naur linux-3.3.7.orig/init/Kconfig linux-3.3.7/init/Kconfig
--- linux-3.3.7.orig/init/Kconfig   2012-05-21 21:42:51.000000000 +0300
+++ linux-3.3.7/init/Kconfig    2012-05-23 21:52:22.000000000 +0300
@@ -68,6 +68,14 @@
    depends on BROKEN || !SMP
    default y

+config BLD
+   bool "An alternate CPU load distributor"
+   depends on EXPERIMENTAL && SMP
+   default y
+   help
+     This is an alternate CPU load distribution technique based
+     on The Barbershop Load Distribution algorithm.
+
 config INIT_ENV_ARG_LIMIT
    int
    default 32 if !UML
diff -Naur linux-3.3.7.orig/kernel/sched/bld.h linux-3.3.7/kernel/sched/bld.h
--- linux-3.3.7.orig/kernel/sched/bld.h 1970-01-01 03:00:00.000000000 +0300
+++ linux-3.3.7/kernel/sched/bld.h  2012-05-23 21:52:22.000000000 +0300
@@ -0,0 +1,112 @@
+#ifdef CONFIG_BLD
+
+static DEFINE_RWLOCK(disp_list_lock);
+static LIST_HEAD(rq_head);
+
+static inline int list_is_first(const struct list_head *list,
+               const struct list_head *head)
+{
+   return list == head->next;
+}
+
+static inline int select_cpu_for_wakeup(struct task_struct *p, int sd_flags, int wake_flags)
+{
+   int cpu = smp_processor_id(), prev_cpu = task_cpu(p), i;
+   /*bool sync = wake_flags & WF_SYNC; */
+   unsigned long load, min_load = ULONG_MAX;
+   struct cpumask *mask;
+
+   if (wake_flags & WF_SYNC) {
+       if (cpu == prev_cpu)
+           return cpu;
+       mask = sched_group_cpus(cpu_rq(prev_cpu)->sd->groups);
+   } else
+       mask = sched_domain_span(cpu_rq(prev_cpu)->sd);
+
+   for_each_cpu(i, mask) {
+       load = cpu_rq(i)->load.weight;
+       if (load < min_load) {
+           min_load = load;
+           cpu = i;
+       }
+   }
+   return cpu;
+}
+
+static int bld_select_task_rq(struct task_struct *p, int sd_flags, int wake_flags)
+{
+   struct rq *tmp;
+   unsigned long flag;
+   unsigned int cpu = smp_processor_id();
+
+   if (&p->cpus_allowed) {
+       struct cpumask *taskmask;
+       unsigned long min_load = ULONG_MAX, load, i;
+       taskmask = tsk_cpus_allowed(p);
+       for_each_cpu(i, taskmask) {
+           load = cpu_rq(i)->load.weight;
+           if (load < min_load) {
+               min_load = load;
+               cpu = i;
+           }
+       }
+   } else  if (sd_flags & SD_BALANCE_WAKE) {
+       cpu = select_cpu_for_wakeup(p, sd_flags, wake_flags);
+       return cpu;
+   } else {
+       read_lock_irqsave(&disp_list_lock, flag);
+       list_for_each_entry(tmp, &rq_head, disp_load_balance) {
+           cpu = cpu_of(tmp);
+           if (cpu_online(cpu))
+               break;
+       }
+       read_unlock_irqrestore(&disp_list_lock, flag);
+   }
+   return cpu;
+}
+
+static void bld_track_load_activate(struct rq *rq)
+{
+   unsigned long  flag;
+   rq->this_cpu_load = rq->load.weight;
+
+   if (rq->pos != 2) { /* if rq isn't the last one */
+       struct rq *last;
+       write_lock_irqsave(&disp_list_lock, flag);
+       last = list_entry(rq_head.prev, struct rq, disp_load_balance);
+       if (rq->this_cpu_load > last->this_cpu_load) {
+           list_del(&rq->disp_load_balance);
+           list_add_tail(&rq->disp_load_balance, &rq_head);
+           rq->pos = 2; last->pos = 1;
+       }
+       write_unlock_irqrestore(&disp_list_lock, flag);
+   }
+}
+
+static void bld_track_load_deactivate(struct rq *rq)
+{
+   unsigned long flag;
+
+   rq->this_cpu_load = rq->load.weight;
+
+   if (rq->pos != 0) { /* If rq isn't first one */
+       struct rq *first;
+       first = list_entry(rq_head.prev, struct rq, disp_load_balance);
+       write_lock_irqsave(&disp_list_lock, flag);
+       if (rq->this_cpu_load <= first->this_cpu_load) {
+           list_del(&rq->disp_load_balance);
+           list_add_tail(&rq->disp_load_balance, &rq_head);
+           rq->pos = 0; first->pos = 1;
+       }
+       write_unlock_irqrestore(&disp_list_lock, flag);
+   }
+}
+#else
+static inline void bld_track_load_activate(struct rq *rq)
+{
+}
+
+static inline void bld_track_load_deactivate(struct rq *rq)
+{
+}
+#endif /* CONFIG_BLD */
diff -Naur linux-3.3.7.orig/kernel/sched/core.c linux-3.3.7/kernel/sched/core.c
--- linux-3.3.7.orig/kernel/sched/core.c    2012-05-21 21:42:51.000000000 +0300
+++ linux-3.3.7/kernel/sched/core.c 2012-05-23 21:52:22.000000000 +0300
@@ -24,6 +24,8 @@
  *  2007-07-01  Group scheduling enhancements by Srivatsa Vaddagiri
  *  2007-11-29  RT balancing improvements by Steven Rostedt, Gregory Haskins,
  *              Thomas Gleixner, Mike Kravetz
+ *  2012-Feb   The Barbershop Load Distribution (BLD) algorithm, an alternate
+ *             load distribution algorithm by Rakib Mullick.
  */

 #include <linux/mm.h>
@@ -81,6 +83,7 @@

 #include "sched.h"
 #include "../workqueue_sched.h"
+#include "bld.h"

 #define CREATE_TRACE_POINTS
 #include <trace/events/sched.h>
@@ -578,6 +581,7 @@
  */
 void wake_up_idle_cpu(int cpu)
 {
+#ifndef CONFIG_BLD
    struct rq *rq = cpu_rq(cpu);

    if (cpu == smp_processor_id())
@@ -604,6 +608,7 @@
    smp_mb();
    if (!tsk_is_polling(rq->idle))
        smp_send_reschedule(cpu);
+#endif
 }

 static inline bool got_nohz_idle_kick(void)
@@ -730,6 +735,7 @@
        rq->nr_uninterruptible--;

    enqueue_task(rq, p, flags);
+   bld_track_load_activate(rq);
 }

 void deactivate_task(struct rq *rq, struct task_struct *p, int flags)
@@ -738,6 +744,7 @@
        rq->nr_uninterruptible++;

    dequeue_task(rq, p, flags);
+   bld_track_load_deactivate(rq);
 }

 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
@@ -1297,7 +1304,12 @@
 static inline
 int select_task_rq(struct task_struct *p, int sd_flags, int wake_flags)
 {
-   int cpu = p->sched_class->select_task_rq(p, sd_flags, wake_flags);
+   int cpu;
+#ifdef CONFIG_BLD
+   cpu = bld_select_task_rq(p, sd_flags, wake_flags);
+#else
+   cpu = p->sched_class->select_task_rq(p, sd_flags, wake_flags);
+#endif

    /*
     * In order not to call set_task_cpu() on a blocking task we need
@@ -1453,7 +1465,11 @@

 void scheduler_ipi(void)
 {
+#ifndef CONFIG_BLD
    if (llist_empty(&this_rq()->wake_list) && !got_nohz_idle_kick())
+#else
+   if (llist_empty(&this_rq()->wake_list))
+#endif
        return;

    /*
@@ -1475,10 +1491,12 @@
    /*
     * Check if someone kicked us for doing the nohz idle load balance.
     */
+#ifndef CONFIG_BLD
    if (unlikely(got_nohz_idle_kick() && !need_resched())) {
        this_rq()->idle_balance = 1;
        raise_softirq_irqoff(SCHED_SOFTIRQ);
    }
+#endif
    irq_exit();
 }

@@ -1518,12 +1536,14 @@
    struct rq *rq = cpu_rq(cpu);

 #if defined(CONFIG_SMP)
+#ifndef CONFIG_BLD
    if (sched_feat(TTWU_QUEUE) && !ttwu_share_cache(smp_processor_id(), cpu)) {
        sched_clock_cpu(cpu); /* sync clocks x-cpu */
        ttwu_queue_remote(p, cpu);
        return;
    }
 #endif
+#endif

    raw_spin_lock(&rq->lock);
    ttwu_do_activate(rq, p, 0);
@@ -2268,6 +2288,7 @@
  */
 static void calc_global_nohz(void)
 {
+#ifndef CONFIG_BLD
    long delta, active, n;

    /*
@@ -2300,6 +2321,7 @@
    avenrun[2] = calc_load_n(avenrun[2], EXP_15, active, n);

    calc_load_update += n * LOAD_FREQ;
+#endif
 }
 #else
 void calc_load_account_idle(struct rq *this_rq)
@@ -3001,8 +3023,10 @@

 #ifdef CONFIG_SMP
    rq->idle_balance = idle_cpu(cpu);
+#ifndef CONFIG_BLD
    trigger_load_balance(rq, cpu);
 #endif
+#endif
 }

 notrace unsigned long get_parent_ip(unsigned long addr)
@@ -3191,10 +3215,10 @@
    }

    pre_schedule(rq, prev);
-
+#ifndef CONFIG_BLD
    if (unlikely(!rq->nr_running))
        idle_balance(cpu, rq);
-
+#endif
    put_prev_task(rq, prev);
    next = pick_next_task(rq);
    clear_tsk_need_resched(prev);
@@ -6946,6 +6970,11 @@
 #endif
        init_rq_hrtick(rq);
        atomic_set(&rq->nr_iowait, 0);
+#ifdef CONFIG_BLD
+       INIT_LIST_HEAD(&rq->disp_load_balance);
+       list_add_tail(&rq->disp_load_balance, &rq_head);
+       rq->pos = 0;
+#endif
    }

    set_load_weight(&init_task);
diff -Naur linux-3.3.7.orig/kernel/sched/fair.c linux-3.3.7/kernel/sched/fair.c
--- linux-3.3.7.orig/kernel/sched/fair.c    2012-05-21 21:42:51.000000000 +0300
+++ linux-3.3.7/kernel/sched/fair.c 2012-05-23 21:52:34.000000000 +0300
@@ -5611,7 +5611,9 @@
 __init void init_sched_fair_class(void)
 {
 #ifdef CONFIG_SMP
+#ifndef CONFIG_BLD
    open_softirq(SCHED_SOFTIRQ, run_rebalance_domains);
+#endif /* BLD */

 #ifdef CONFIG_NO_HZ
    zalloc_cpumask_var(&nohz.idle_cpus_mask, GFP_NOWAIT);
diff -Naur linux-3.3.7.orig/kernel/sched/fair.c.orig linux-3.3.7/kernel/sched/fair.c.orig
--- linux-3.3.7.orig/kernel/sched/fair.c.orig   1970-01-01 03:00:00.000000000 +0300
+++ linux-3.3.7/kernel/sched/fair.c.orig    2012-05-23 21:52:34.000000000 +0300
@@ -0,0 +1,5622 @@
+/*
+ * Completely Fair Scheduling (CFS) Class (SCHED_NORMAL/SCHED_BATCH)
+ *
+ *  Copyright (C) 2007 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
+ *
+ *  Interactivity improvements by Mike Galbraith
+ *  (C) 2007 Mike Galbraith <efault@gmx.de>
+ *
+ *  Various enhancements by Dmitry Adamushko.
+ *  (C) 2007 Dmitry Adamushko <dmitry.adamushko@gmail.com>
+ *
+ *  Group scheduling enhancements by Srivatsa Vaddagiri
+ *  Copyright IBM Corporation, 2007
+ *  Author: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
+ *
+ *  Scaled math optimizations by Thomas Gleixner
+ *  Copyright (C) 2007, Thomas Gleixner <tglx@linutronix.de>
+ *
+ *  Adaptive scheduling granularity, math enhancements by Peter Zijlstra
+ *  Copyright (C) 2007 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
+ */
+
+#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:
+ * (default: 6ms * (1 + ilog(ncpus)), units: nanoseconds)
+ *
+ * NOTE: this latency value is not the same as the concept of
+ * 'timeslice length' - timeslices in CFS are of variable length
+ * and have no persistent notion like in traditional, time-slice
+ * based scheduling concepts.
+ *
+ * (to see the precise effective timeslice length of your workload,
+ *  run vmstat and monitor the context-switches (cs) field)
+ */
+unsigned int sysctl_sched_latency = 6000000ULL;
+unsigned int normalized_sysctl_sched_latency = 6000000ULL;
+
+/*
+ * The initial- and re-scaling of tunables is configurable
+ * (default SCHED_TUNABLESCALING_LOG = *(1+ilog(ncpus))
+ *
+ * Options are:
+ * SCHED_TUNABLESCALING_NONE - unscaled, always *1
+ * SCHED_TUNABLESCALING_LOG - scaled logarithmical, *1+ilog(ncpus)
+ * SCHED_TUNABLESCALING_LINEAR - scaled linear, *ncpus
+ */
+enum sched_tunable_scaling sysctl_sched_tunable_scaling
+   = SCHED_TUNABLESCALING_LOG;
+
+/*
+ * Minimal preemption granularity for CPU-bound tasks:
+ * (default: 0.75 msec * (1 + ilog(ncpus)), units: nanoseconds)
+ */
+unsigned int sysctl_sched_min_granularity = 750000ULL;
+unsigned int normalized_sysctl_sched_min_granularity = 750000ULL;
+
+/*
+ * is kept at sysctl_sched_latency / sysctl_sched_min_granularity
+ */
+static unsigned int sched_nr_latency = 8;
+
+/*
+ * After fork, child runs first. If set to 0 (default) then
+ * parent will (try to) run first.
+ */
+unsigned int sysctl_sched_child_runs_first __read_mostly;
+
+/*
+ * SCHED_OTHER wake-up granularity.
+ * (default: 1 msec * (1 + ilog(ncpus)), units: nanoseconds)
+ *
+ * This option delays the preemption effects of decoupled workloads
+ * and reduces their over-scheduling. Synchronous workloads will still
+ * have immediate wakeup/sleep latencies.
+ */
+unsigned int sysctl_sched_wakeup_granularity = 1000000UL;
+unsigned int normalized_sysctl_sched_wakeup_granularity = 1000000UL;
+
+const_debug unsigned int sysctl_sched_migration_cost = 500000UL;
+
+/*
+ * The exponential sliding  window over which load is averaged for shares
+ * distribution.
+ * (default: 10msec)
+ */
+unsigned int __read_mostly sysctl_sched_shares_window = 10000000UL;
+
+#ifdef CONFIG_CFS_BANDWIDTH
+/*
+ * Amount of runtime to allocate from global (tg) to local (per-cfs_rq) pool
+ * each time a cfs_rq requests quota.
+ *
+ * Note: in the case that the slice exceeds the runtime remaining (either due
+ * to consumption or the quota being specified to be smaller than the slice)
+ * we will always only issue the remaining available time.
+ *
+ * default: 5 msec, units: microseconds
+  */
+unsigned int sysctl_sched_cfs_bandwidth_slice = 5000UL;
+#endif
+
+/*
+ * 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:
+ */
+
+#ifdef CONFIG_FAIR_GROUP_SCHED
+
+/* cpu runqueue to which this cfs_rq is attached */
+static inline struct rq *rq_of(struct cfs_rq *cfs_rq)
+{
+   return cfs_rq->rq;
+}
+
+/* An entity is a task if it doesn't "own" a runqueue */
+#define entity_is_task(se) (!se->my_q)
+
+static inline struct task_struct *task_of(struct sched_entity *se)
+{
+#ifdef CONFIG_SCHED_DEBUG
+   WARN_ON_ONCE(!entity_is_task(se));
+#endif
+   return container_of(se, struct task_struct, se);
+}
+
+/* Walk up scheduling entities hierarchy */
+#define for_each_sched_entity(se) \
+       for (; se; se = se->parent)
+
+static inline struct cfs_rq *task_cfs_rq(struct task_struct *p)
+{
+   return p->se.cfs_rq;
+}
+
+/* runqueue on which this entity is (to be) queued */
+static inline struct cfs_rq *cfs_rq_of(struct sched_entity *se)
+{
+   return se->cfs_rq;
+}
+
+/* runqueue "owned" by this group */
+static inline struct cfs_rq *group_cfs_rq(struct sched_entity *grp)
+{
+   return grp->my_q;
+}
+
+static inline void list_add_leaf_cfs_rq(struct cfs_rq *cfs_rq)
+{
+   if (!cfs_rq->on_list) {
+       /*
+        * Ensure we either appear before our parent (if already
+        * enqueued) or force our parent to appear after us when it is
+        * enqueued.  The fact that we always enqueue bottom-up
+        * reduces this to two cases.
+        */
+       if (cfs_rq->tg->parent &&
+           cfs_rq->tg->parent->cfs_rq[cpu_of(rq_of(cfs_rq))]->on_list) {
+           list_add_rcu(&cfs_rq->leaf_cfs_rq_list,
+               &rq_of(cfs_rq)->leaf_cfs_rq_list);
+       } else {
+           list_add_tail_rcu(&cfs_rq->leaf_cfs_rq_list,
+               &rq_of(cfs_rq)->leaf_cfs_rq_list);
+       }
+
+       cfs_rq->on_list = 1;
+   }
+}
+
+static inline void list_del_leaf_cfs_rq(struct cfs_rq *cfs_rq)
+{
+   if (cfs_rq->on_list) {
+       list_del_rcu(&cfs_rq->leaf_cfs_rq_list);
+       cfs_rq->on_list = 0;
+   }
+}
+
+/* Iterate thr' all leaf cfs_rq's on a runqueue */
+#define for_each_leaf_cfs_rq(rq, cfs_rq) \
+   list_for_each_entry_rcu(cfs_rq, &rq->leaf_cfs_rq_list, leaf_cfs_rq_list)
+
+/* Do the two (enqueued) entities belong to the same group ? */
+static inline int
+is_same_group(struct sched_entity *se, struct sched_entity *pse)
+{
+   if (se->cfs_rq == pse->cfs_rq)
+       return 1;
+
+   return 0;
+}
+
+static inline struct sched_entity *parent_entity(struct sched_entity *se)
+{
+   return se->parent;
+}
+
+/* return depth at which a sched entity is present in the hierarchy */
+static inline int depth_se(struct sched_entity *se)
+{
+   int depth = 0;
+
+   for_each_sched_entity(se)
+       depth++;
+
+   return depth;
+}
+
+static void
+find_matching_se(struct sched_entity **se, struct sched_entity **pse)
+{
+   int se_depth, pse_depth;
+
+   /*
+    * preemption test can be made between sibling entities who are in the
+    * same cfs_rq i.e who have a common parent. Walk up the hierarchy of
+    * both tasks until we find their ancestors who are siblings of common
+    * parent.
+    */
+
+   /* First walk up until both entities are at same depth */
+   se_depth = depth_se(*se);
+   pse_depth = depth_se(*pse);
+
+   while (se_depth > pse_depth) {
+       se_depth--;
+       *se = parent_entity(*se);
+   }
+
+   while (pse_depth > se_depth) {
+       pse_depth--;
+       *pse = parent_entity(*pse);
+   }
+
+   while (!is_same_group(*se, *pse)) {
+       *se = parent_entity(*se);
+       *pse = parent_entity(*pse);
+   }
+}
+
+#else  /* !CONFIG_FAIR_GROUP_SCHED */
+
+static inline struct task_struct *task_of(struct sched_entity *se)
+{
+   return container_of(se, struct task_struct, se);
+}
+
+static inline struct rq *rq_of(struct cfs_rq *cfs_rq)
+{
+   return container_of(cfs_rq, struct rq, cfs);
+}
+
+#define entity_is_task(se) 1
+
+#define for_each_sched_entity(se) \
+       for (; se; se = NULL)
+
+static inline struct cfs_rq *task_cfs_rq(struct task_struct *p)
+{
+   return &task_rq(p)->cfs;
+}
+
+static inline struct cfs_rq *cfs_rq_of(struct sched_entity *se)
+{
+   struct task_struct *p = task_of(se);
+   struct rq *rq = task_rq(p);
+
+   return &rq->cfs;
+}
+
+/* runqueue "owned" by this group */
+static inline struct cfs_rq *group_cfs_rq(struct sched_entity *grp)
+{
+   return NULL;
+}
+
+static inline void list_add_leaf_cfs_rq(struct cfs_rq *cfs_rq)
+{
+}
+
+static inline void list_del_leaf_cfs_rq(struct cfs_rq *cfs_rq)
+{
+}
+
+#define for_each_leaf_cfs_rq(rq, cfs_rq) \
+       for (cfs_rq = &rq->cfs; cfs_rq; cfs_rq = NULL)
+
+static inline int
+is_same_group(struct sched_entity *se, struct sched_entity *pse)
+{
+   return 1;
+}
+
+static inline struct sched_entity *parent_entity(struct sched_entity *se)
+{
+   return NULL;
+}
+
+static inline void
+find_matching_se(struct sched_entity **se, struct sched_entity **pse)
+{
+}
+
+#endif /* CONFIG_FAIR_GROUP_SCHED */
+
+static void account_cfs_rq_runtime(struct cfs_rq *cfs_rq,
+                  unsigned long delta_exec);
+
+/**************************************************************
+ * Scheduling class tree data structure manipulation methods:
+ */
+
+static inline u64 max_vruntime(u64 min_vruntime, u64 vruntime)
+{
+   s64 delta = (s64)(vruntime - min_vruntime);
+   if (delta > 0)
+       min_vruntime = vruntime;
+
+   return min_vruntime;
+}
+
+static inline u64 min_vruntime(u64 min_vruntime, u64 vruntime)
+{
+   s64 delta = (s64)(vruntime - min_vruntime);
+   if (delta < 0)
+       min_vruntime = vruntime;
+
+   return min_vruntime;
+}
+
+static inline int entity_before(struct sched_entity *a,
+               struct sched_entity *b)
+{
+   return (s64)(a->vruntime - b->vruntime) < 0;
+}
+
+static void update_min_vruntime(struct cfs_rq *cfs_rq)
+{
+   u64 vruntime = cfs_rq->min_vruntime;
+
+   if (cfs_rq->curr)
+       vruntime = cfs_rq->curr->vruntime;
+
+   if (cfs_rq->rb_leftmost) {
+       struct sched_entity *se = rb_entry(cfs_rq->rb_leftmost,
+                          struct sched_entity,
+                          run_node);
+
+       if (!cfs_rq->curr)
+           vruntime = se->vruntime;
+       else
+           vruntime = min_vruntime(vruntime, se->vruntime);
+   }
+
+   cfs_rq->min_vruntime = max_vruntime(cfs_rq->min_vruntime, vruntime);
+#ifndef CONFIG_64BIT
+   smp_wmb();
+   cfs_rq->min_vruntime_copy = cfs_rq->min_vruntime;
+#endif
+}
+
+/*
+ * Enqueue an entity into the rb-tree:
+ */
+static void __enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
+{
+   struct rb_node **link = &cfs_rq->tasks_timeline.rb_node;
+   struct rb_node *parent = NULL;
+   struct sched_entity *entry;
+   int leftmost = 1;
+
+   /*
+    * Find the right place in the rbtree:
+    */
+   while (*link) {
+       parent = *link;
+       entry = rb_entry(parent, struct sched_entity, run_node);
+       /*
+        * We dont care about collisions. Nodes with
+        * the same key stay together.
+        */
+       if (entity_before(se, entry)) {
+           link = &parent->rb_left;
+       } else {
+           link = &parent->rb_right;
+           leftmost = 0;
+       }
+   }
+
+   /*
+    * Maintain a cache of leftmost tree entries (it is frequently
+    * used):
+    */
+   if (leftmost)
+       cfs_rq->rb_leftmost = &se->run_node;
+
+   rb_link_node(&se->run_node, parent, link);
+   rb_insert_color(&se->run_node, &cfs_rq->tasks_timeline);
+}
+
+static void __dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
+{
+   if (cfs_rq->rb_leftmost == &se->run_node) {
+       struct rb_node *next_node;
+
+       next_node = rb_next(&se->run_node);
+       cfs_rq->rb_leftmost = next_node;
+   }
+
+   rb_erase(&se->run_node, &cfs_rq->tasks_timeline);
+}
+
+struct sched_entity *__pick_first_entity(struct cfs_rq *cfs_rq)
+{
+   struct rb_node *left = cfs_rq->rb_leftmost;
+
+   if (!left)
+       return NULL;
+
+   return rb_entry(left, struct sched_entity, run_node);
+}
+
+static struct sched_entity *__pick_next_entity(struct sched_entity *se)
+{
+   struct rb_node *next = rb_next(&se->run_node);
+
+   if (!next)
+       return NULL;
+
+   return rb_entry(next, struct sched_entity, run_node);
+}
+
+#ifdef CONFIG_SCHED_DEBUG
+struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq)
+{
+   struct rb_node *last = rb_last(&cfs_rq->tasks_timeline);
+
+   if (!last)
+       return NULL;
+
+   return rb_entry(last, struct sched_entity, run_node);
+}
+
+/**************************************************************
+ * Scheduling class statistics methods:
+ */
+
+int sched_proc_update_handler(struct ctl_table *table, int write,
+       void __user *buffer, size_t *lenp,
+       loff_t *ppos)
+{
+   int ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
+   int factor = get_update_sysctl_factor();
+
+   if (ret || !write)
+       return ret;
+
+   sched_nr_latency = DIV_ROUND_UP(sysctl_sched_latency,
+                   sysctl_sched_min_granularity);
+
+#define WRT_SYSCTL(name) \
+   (normalized_sysctl_##name = sysctl_##name / (factor))
+   WRT_SYSCTL(sched_min_granularity);
+   WRT_SYSCTL(sched_latency);
+   WRT_SYSCTL(sched_wakeup_granularity);
+#undef WRT_SYSCTL
+
+   return 0;
+}
+#endif
+
+/*
+ * delta /= w
+ */
+static inline unsigned long
+calc_delta_fair(unsigned long delta, struct sched_entity *se)
+{
+   if (unlikely(se->load.weight != NICE_0_LOAD))
+       delta = calc_delta_mine(delta, NICE_0_LOAD, &se->load);
+
+   return delta;
+}
+
+/*
+ * The idea is to set a period in which each task runs once.
+ *
+ * When there are too many tasks (sysctl_sched_nr_latency) we have to stretch
+ * this period because otherwise the slices get too small.
+ *
+ * p = (nr <= nl) ? l : l*nr/nl
+ */
+static u64 __sched_period(unsigned long nr_running)
+{
+   u64 period = sysctl_sched_latency;
+   unsigned long nr_latency = sched_nr_latency;
+
+   if (unlikely(nr_running > nr_latency)) {
+       period = sysctl_sched_min_granularity;
+       period *= nr_running;
+   }
+
+   return period;
+}
+
+/*
+ * We calculate the wall-time slice from the period by taking a part
+ * proportional to the weight.
+ *
+ * s = p*P[w/rw]
+ */
+static u64 sched_slice(struct cfs_rq *cfs_rq, struct sched_entity *se)
+{
+   u64 slice = __sched_period(cfs_rq->nr_running + !se->on_rq);
+
+   for_each_sched_entity(se) {
+       struct load_weight *load;
+       struct load_weight lw;
+
+       cfs_rq = cfs_rq_of(se);
+       load = &cfs_rq->load;
+
+       if (unlikely(!se->on_rq)) {
+           lw = cfs_rq->load;
+
+           update_load_add(&lw, se->load.weight);
+           load = &lw;
+       }
+       slice = calc_delta_mine(slice, se->load.weight, load);
+   }
+   return slice;
+}
+
+/*
+ * We calculate the vruntime slice of a to be inserted task
+ *
+ * vs = s/w
+ */
+static u64 sched_vslice(struct cfs_rq *cfs_rq, struct sched_entity *se)
+{
+   return calc_delta_fair(sched_slice(cfs_rq, se), se);
+}
+
+static void update_cfs_load(struct cfs_rq *cfs_rq, int global_update);
+static void update_cfs_shares(struct cfs_rq *cfs_rq);
+
+/*
+ * Update the current task's runtime statistics. Skip current tasks that
+ * are not in our scheduling class.
+ */
+static inline void
+__update_curr(struct cfs_rq *cfs_rq, struct sched_entity *curr,
+         unsigned long delta_exec)
+{
+   unsigned long delta_exec_weighted;
+
+   schedstat_set(curr->statistics.exec_max,
+             max((u64)delta_exec, curr->statistics.exec_max));
+
+   curr->sum_exec_runtime += delta_exec;
+   schedstat_add(cfs_rq, exec_clock, delta_exec);
+   delta_exec_weighted = calc_delta_fair(delta_exec, curr);
+
+   curr->vruntime += delta_exec_weighted;
+   update_min_vruntime(cfs_rq);
+
+#if defined CONFIG_SMP && defined CONFIG_FAIR_GROUP_SCHED
+   cfs_rq->load_unacc_exec_time += delta_exec;
+#endif
+}
+
+static void update_curr(struct cfs_rq *cfs_rq)
+{
+   struct sched_entity *curr = cfs_rq->curr;
+   u64 now = rq_of(cfs_rq)->clock_task;
+   unsigned long delta_exec;
+
+   if (unlikely(!curr))
+       return;
+
+   /*
+    * Get the amount of time the current task was running
+    * since the last time we changed load (this cannot
+    * overflow on 32 bits):
+    */
+   delta_exec = (unsigned long)(now - curr->exec_start);
+   if (!delta_exec)
+       return;
+
+   __update_curr(cfs_rq, curr, delta_exec);
+   curr->exec_start = now;
+
+   if (entity_is_task(curr)) {
+       struct task_struct *curtask = task_of(curr);
+
+       trace_sched_stat_runtime(curtask, delta_exec, curr->vruntime);
+       cpuacct_charge(curtask, delta_exec);
+       account_group_exec_runtime(curtask, delta_exec);
+   }
+
+   account_cfs_rq_runtime(cfs_rq, delta_exec);
+}
+
+static inline void
+update_stats_wait_start(struct cfs_rq *cfs_rq, struct sched_entity *se)
+{
+   schedstat_set(se->statistics.wait_start, rq_of(cfs_rq)->clock);
+}
+
+/*
+ * Task is being enqueued - update stats:
+ */
+static void update_stats_enqueue(struct cfs_rq *cfs_rq, struct sched_entity *se)
+{
+   /*
+    * Are we enqueueing a waiting task? (for current tasks
+    * a dequeue/enqueue event is a NOP)
+    */
+   if (se != cfs_rq->curr)
+       update_stats_wait_start(cfs_rq, se);
+}
+
+static void
+update_stats_wait_end(struct cfs_rq *cfs_rq, struct sched_entity *se)
+{
+   schedstat_set(se->statistics.wait_max, max(se->statistics.wait_max,
+           rq_of(cfs_rq)->clock - se->statistics.wait_start));
+   schedstat_set(se->statistics.wait_count, se->statistics.wait_count + 1);
+   schedstat_set(se->statistics.wait_sum, se->statistics.wait_sum +
+           rq_of(cfs_rq)->clock - se->statistics.wait_start);
+#ifdef CONFIG_SCHEDSTATS
+   if (entity_is_task(se)) {
+       trace_sched_stat_wait(task_of(se),
+           rq_of(cfs_rq)->clock - se->statistics.wait_start);
+   }
+#endif
+   schedstat_set(se->statistics.wait_start, 0);
+}
+
+static inline void
+update_stats_dequeue(struct cfs_rq *cfs_rq, struct sched_entity *se)
+{
+   /*
+    * Mark the end of the wait period if dequeueing a
+    * waiting task:
+    */
+   if (se != cfs_rq->curr)
+       update_stats_wait_end(cfs_rq, se);
+}
+
+/*
+ * We are picking a new current task - update its stats:
+ */
+static inline void
+update_stats_curr_start(struct cfs_rq *cfs_rq, struct sched_entity *se)
+{
+   /*
+    * We are starting a new run period:
+    */
+   se->exec_start = rq_of(cfs_rq)->clock_task;
+}
+
+/**************************************************
+ * Scheduling class queueing methods:
+ */
+
+#if defined CONFIG_SMP && defined CONFIG_FAIR_GROUP_SCHED
+static void
+add_cfs_task_weight(struct cfs_rq *cfs_rq, unsigned long weight)
+{
+   cfs_rq->task_weight += weight;
+}
+#else
+static inline void
+add_cfs_task_weight(struct cfs_rq *cfs_rq, unsigned long weight)
+{
+}
+#endif
+
+static void
+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))
+       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);
+   }
+   cfs_rq->nr_running++;
+}
+
+static void
+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))
+       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);
+   }
+   cfs_rq->nr_running--;
+}
+
+#ifdef CONFIG_FAIR_GROUP_SCHED
+/* we need this in update_cfs_load and load-balance functions below */
+static inline int throttled_hierarchy(struct cfs_rq *cfs_rq);
+# ifdef CONFIG_SMP
+static void update_cfs_rq_load_contribution(struct cfs_rq *cfs_rq,
+                       int global_update)
+{
+   struct task_group *tg = cfs_rq->tg;
+   long load_avg;
+
+   load_avg = div64_u64(cfs_rq->load_avg, cfs_rq->load_period+1);
+   load_avg -= cfs_rq->load_contribution;
+
+   if (global_update || abs(load_avg) > cfs_rq->load_contribution / 8) {
+       atomic_add(load_avg, &tg->load_weight);
+       cfs_rq->load_contribution += load_avg;
+   }
+}
+
+static void update_cfs_load(struct cfs_rq *cfs_rq, int global_update)
+{
+   u64 period = sysctl_sched_shares_window;
+   u64 now, delta;
+   unsigned long load = cfs_rq->load.weight;
+
+   if (cfs_rq->tg == &root_task_group || throttled_hierarchy(cfs_rq))
+       return;
+
+   now = rq_of(cfs_rq)->clock_task;
+   delta = now - cfs_rq->load_stamp;
+
+   /* truncate load history at 4 idle periods */
+   if (cfs_rq->load_stamp > cfs_rq->load_last &&
+       now - cfs_rq->load_last > 4 * period) {
+       cfs_rq->load_period = 0;
+       cfs_rq->load_avg = 0;
+       delta = period - 1;
+   }
+
+   cfs_rq->load_stamp = now;
+   cfs_rq->load_unacc_exec_time = 0;
+   cfs_rq->load_period += delta;
+   if (load) {
+       cfs_rq->load_last = now;
+       cfs_rq->load_avg += delta * load;
+   }
+
+   /* consider updating load contribution on each fold or truncate */
+   if (global_update || cfs_rq->load_period > period
+       || !cfs_rq->load_period)
+       update_cfs_rq_load_contribution(cfs_rq, global_update);
+
+   while (cfs_rq->load_period > 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" (cfs_rq->load_period));
+       cfs_rq->load_period /= 2;
+       cfs_rq->load_avg /= 2;
+   }
+
+   if (!cfs_rq->curr && !cfs_rq->nr_running && !cfs_rq->load_avg)
+       list_del_leaf_cfs_rq(cfs_rq);
+}
+
+static inline long calc_tg_weight(struct task_group *tg, struct cfs_rq *cfs_rq)
+{
+   long tg_weight;
+
+   /*
+    * Use this CPU's actual weight instead of the last load_contribution
+    * to gain a more accurate current total weight. See
+    * update_cfs_rq_load_contribution().
+    */
+   tg_weight = atomic_read(&tg->load_weight);
+   tg_weight -= cfs_rq->load_contribution;
+   tg_weight += cfs_rq->load.weight;
+
+   return tg_weight;
+}
+
+static long calc_cfs_shares(struct cfs_rq *cfs_rq, struct task_group *tg)
+{
+   long tg_weight, load, shares;
+
+   tg_weight = calc_tg_weight(tg, cfs_rq);
+   load = cfs_rq->load.weight;
+
+   shares = (tg->shares * load);
+   if (tg_weight)
+       shares /= tg_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);
+   }
+}
+# 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)
+{
+   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)
+{
+   if (se->on_rq) {
+       /* commit outstanding execution time */
+       if (cfs_rq->curr == se)
+           update_curr(cfs_rq);
+       account_entity_dequeue(cfs_rq, se);
+   }
+
+   update_load_set(&se->load, weight);
+
+   if (se->on_rq)
+       account_entity_enqueue(cfs_rq, se);
+}
+
+static void update_cfs_shares(struct cfs_rq *cfs_rq)
+{
+   struct task_group *tg;
+   struct sched_entity *se;
+   long shares;
+
+   tg = cfs_rq->tg;
+   se = tg->se[cpu_of(rq_of(cfs_rq))];
+   if (!se || throttled_hierarchy(cfs_rq))
+       return;
+#ifndef CONFIG_SMP
+   if (likely(se->load.weight == tg->shares))
+       return;
+#endif
+   shares = calc_cfs_shares(cfs_rq, tg);
+
+   reweight_entity(cfs_rq_of(se), se, shares);
+}
+#else /* CONFIG_FAIR_GROUP_SCHED */
+static void update_cfs_load(struct cfs_rq *cfs_rq, int global_update)
+{
+}
+
+static inline void update_cfs_shares(struct cfs_rq *cfs_rq)
+{
+}
+
+static inline void update_entity_shares_tick(struct cfs_rq *cfs_rq)
+{
+}
+#endif /* CONFIG_FAIR_GROUP_SCHED */
+
+static void enqueue_sleeper(struct cfs_rq *cfs_rq, struct sched_entity *se)
+{
+#ifdef CONFIG_SCHEDSTATS
+   struct task_struct *tsk = NULL;
+
+   if (entity_is_task(se))
+       tsk = task_of(se);
+
+   if (se->statistics.sleep_start) {
+       u64 delta = rq_of(cfs_rq)->clock - se->statistics.sleep_start;
+
+       if ((s64)delta < 0)
+           delta = 0;
+
+       if (unlikely(delta > se->statistics.sleep_max))
+           se->statistics.sleep_max = delta;
+
+       se->statistics.sleep_start = 0;
+       se->statistics.sum_sleep_runtime += delta;
+
+       if (tsk) {
+           account_scheduler_latency(tsk, delta >> 10, 1);
+           trace_sched_stat_sleep(tsk, delta);
+       }
+   }
+   if (se->statistics.block_start) {
+       u64 delta = rq_of(cfs_rq)->clock - se->statistics.block_start;
+
+       if ((s64)delta < 0)
+           delta = 0;
+
+       if (unlikely(delta > se->statistics.block_max))
+           se->statistics.block_max = delta;
+
+       se->statistics.block_start = 0;
+       se->statistics.sum_sleep_runtime += delta;
+
+       if (tsk) {
+           if (tsk->in_iowait) {
+               se->statistics.iowait_sum += delta;
+               se->statistics.iowait_count++;
+               trace_sched_stat_iowait(tsk, delta);
+           }
+
+           trace_sched_stat_blocked(tsk, delta);
+
+           /*
+            * Blocking time is in units of nanosecs, so shift by
+            * 20 to get a milliseconds-range estimation of the
+            * amount of time that the task spent sleeping:
+            */
+           if (unlikely(prof_on == SLEEP_PROFILING)) {
+               profile_hits(SLEEP_PROFILING,
+                       (void *)get_wchan(tsk),
+                       delta >> 20);
+           }
+           account_scheduler_latency(tsk, delta >> 10, 0);
+       }
+   }
+#endif
+}
+
+static void check_spread(struct cfs_rq *cfs_rq, struct sched_entity *se)
+{
+#ifdef CONFIG_SCHED_DEBUG
+   s64 d = se->vruntime - cfs_rq->min_vruntime;
+
+   if (d < 0)
+       d = -d;
+
+   if (d > 3*sysctl_sched_latency)
+       schedstat_inc(cfs_rq, nr_spread_over);
+#endif
+}
+
+static void
+place_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int initial)
+{
+   u64 vruntime = cfs_rq->min_vruntime;
+
+   /*
+    * The 'current' period is already promised to the current tasks,
+    * however the extra weight of the new task will slow them down a
+    * little, place the new task so that it fits in the slot that
+    * stays open at the end.
+    */
+   if (initial && sched_feat(START_DEBIT))
+       vruntime += sched_vslice(cfs_rq, se);
+
+   /* sleeps up to a single latency don't count. */
+   if (!initial) {
+       unsigned long thresh = sysctl_sched_latency;
+
+       /*
+        * Halve their sleep time's effect, to allow
+        * for a gentler effect of sleepers:
+        */
+       if (sched_feat(GENTLE_FAIR_SLEEPERS))
+           thresh >>= 1;
+
+       vruntime -= thresh;
+   }
+
+   /* ensure we never gain time by being placed backwards. */
+   vruntime = max_vruntime(se->vruntime, vruntime);
+
+   se->vruntime = vruntime;
+}
+
+static void check_enqueue_throttle(struct cfs_rq *cfs_rq);
+
+static void
+enqueue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
+{
+   /*
+    * Update the normalized vruntime before updating min_vruntime
+    * through callig update_curr().
+    */
+   if (!(flags & ENQUEUE_WAKEUP) || (flags & ENQUEUE_WAKING))
+       se->vruntime += cfs_rq->min_vruntime;
+
+   /*
+    * Update run-time statistics of the 'current'.
+    */
+   update_curr(cfs_rq);
+   update_cfs_load(cfs_rq, 0);
+   account_entity_enqueue(cfs_rq, se);
+   update_cfs_shares(cfs_rq);
+
+   if (flags & ENQUEUE_WAKEUP) {
+       place_entity(cfs_rq, se, 0);
+       enqueue_sleeper(cfs_rq, se);
+   }
+
+   update_stats_enqueue(cfs_rq, se);
+   check_spread(cfs_rq, se);
+   if (se != cfs_rq->curr)
+       __enqueue_entity(cfs_rq, se);
+   se->on_rq = 1;
+
+   if (cfs_rq->nr_running == 1) {
+       list_add_leaf_cfs_rq(cfs_rq);
+       check_enqueue_throttle(cfs_rq);
+   }
+}
+
+static void __clear_buddies_last(struct sched_entity *se)
+{
+   for_each_sched_entity(se) {
+       struct cfs_rq *cfs_rq = cfs_rq_of(se);
+       if (cfs_rq->last == se)
+           cfs_rq->last = NULL;
+       else
+           break;
+   }
+}
+
+static void __clear_buddies_next(struct sched_entity *se)
+{
+   for_each_sched_entity(se) {
+       struct cfs_rq *cfs_rq = cfs_rq_of(se);
+       if (cfs_rq->next == se)
+           cfs_rq->next = NULL;
+       else
+           break;
+   }
+}
+
+static void __clear_buddies_skip(struct sched_entity *se)
+{
+   for_each_sched_entity(se) {
+       struct cfs_rq *cfs_rq = cfs_rq_of(se);
+       if (cfs_rq->skip == se)
+           cfs_rq->skip = NULL;
+       else
+           break;
+   }
+}
+
+static void clear_buddies(struct cfs_rq *cfs_rq, struct sched_entity *se)
+{
+   if (cfs_rq->last == se)
+       __clear_buddies_last(se);
+
+   if (cfs_rq->next == se)
+       __clear_buddies_next(se);
+
+   if (cfs_rq->skip == se)
+       __clear_buddies_skip(se);
+}
+
+static void return_cfs_rq_runtime(struct cfs_rq *cfs_rq);
+
+static void
+dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags)
+{
+   /*
+    * Update run-time statistics of the 'current'.
+    */
+   update_curr(cfs_rq);
+
+   update_stats_dequeue(cfs_rq, se);
+   if (flags & DEQUEUE_SLEEP) {
+#ifdef CONFIG_SCHEDSTATS
+       if (entity_is_task(se)) {
+           struct task_struct *tsk = task_of(se);
+
+           if (tsk->state & TASK_INTERRUPTIBLE)
+               se->statistics.sleep_start = rq_of(cfs_rq)->clock;
+           if (tsk->state & TASK_UNINTERRUPTIBLE)
+               se->statistics.block_start = rq_of(cfs_rq)->clock;
+       }
+#endif
+   }
+
+   clear_buddies(cfs_rq, se);
+
+   if (se != cfs_rq->curr)
+       __dequeue_entity(cfs_rq, se);
+   se->on_rq = 0;
+   update_cfs_load(cfs_rq, 0);
+   account_entity_dequeue(cfs_rq, se);
+
+   /*
+    * Normalize the entity after updating the min_vruntime because the
+    * update can refer to the ->curr item and we need to reflect this
+    * movement in our normalized position.
+    */
+   if (!(flags & DEQUEUE_SLEEP))
+       se->vruntime -= cfs_rq->min_vruntime;
+
+   /* return excess runtime on last dequeue */
+   return_cfs_rq_runtime(cfs_rq);
+
+   update_min_vruntime(cfs_rq);
+   update_cfs_shares(cfs_rq);
+}
+
+/*
+ * Preempt the current task with a newly woken task if needed:
+ */
+static void
+check_preempt_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr)
+{
+   unsigned long ideal_runtime, delta_exec;
+   struct sched_entity *se;
+   s64 delta;
+
+   ideal_runtime = sched_slice(cfs_rq, curr);
+   delta_exec = curr->sum_exec_runtime - curr->prev_sum_exec_runtime;
+   if (delta_exec > ideal_runtime) {
+       resched_task(rq_of(cfs_rq)->curr);
+       /*
+        * The current task ran long enough, ensure it doesn't get
+        * re-elected due to buddy favours.
+        */
+       clear_buddies(cfs_rq, curr);
+       return;
+   }
+
+   /*
+    * Ensure that a task that missed wakeup preemption by a
+    * narrow margin doesn't have to wait for a full slice.
+    * This also mitigates buddy induced latencies under load.
+    */
+   if (delta_exec < sysctl_sched_min_granularity)
+       return;
+
+   se = __pick_first_entity(cfs_rq);
+   delta = curr->vruntime - se->vruntime;
+
+   if (delta < 0)
+       return;
+
+   if (delta > ideal_runtime)
+       resched_task(rq_of(cfs_rq)->curr);
+}
+
+static void
+set_next_entity(struct cfs_rq *cfs_rq, struct sched_entity *se)
+{
+   /* 'current' is not kept within the tree. */
+   if (se->on_rq) {
+       /*
+        * Any task has to be enqueued before it get to execute on
+        * a CPU. So account for the time it spent waiting on the
+        * runqueue.
+        */
+       update_stats_wait_end(cfs_rq, se);
+       __dequeue_entity(cfs_rq, se);
+   }
+
+   update_stats_curr_start(cfs_rq, se);
+   cfs_rq->curr = se;
+#ifdef CONFIG_SCHEDSTATS
+   /*
+    * Track our maximum slice length, if the CPU's load is at
+    * least twice that of our own weight (i.e. dont track it
+    * when there are only lesser-weight tasks around):
+    */
+   if (rq_of(cfs_rq)->load.weight >= 2*se->load.weight) {
+       se->statistics.slice_max = max(se->statistics.slice_max,
+           se->sum_exec_runtime - se->prev_sum_exec_runtime);
+   }
+#endif
+   se->prev_sum_exec_runtime = se->sum_exec_runtime;
+}
+
+static int
+wakeup_preempt_entity(struct sched_entity *curr, struct sched_entity *se);
+
+/*
+ * Pick the next process, keeping these things in mind, in this order:
+ * 1) keep things fair between processes/task groups
+ * 2) pick the "next" process, since someone really wants that to run
+ * 3) pick the "last" process, for cache locality
+ * 4) do not run the "skip" process, if something else is available
+ */
+static struct sched_entity *pick_next_entity(struct cfs_rq *cfs_rq)
+{
+   struct sched_entity *se = __pick_first_entity(cfs_rq);
+   struct sched_entity *left = se;
+
+   /*
+    * Avoid running the skip buddy, if running something else can
+    * be done without getting too unfair.
+    */
+   if (cfs_rq->skip == se) {
+       struct sched_entity *second = __pick_next_entity(se);
+       if (second && wakeup_preempt_entity(second, left) < 1)
+           se = second;
+   }
+
+   /*
+    * Prefer last buddy, try to return the CPU to a preempted task.
+    */
+   if (cfs_rq->last && wakeup_preempt_entity(cfs_rq->last, left) < 1)
+       se = cfs_rq->last;
+
+   /*
+    * Someone really wants this to run. If it's not unfair, run it.
+    */
+   if (cfs_rq->next && wakeup_preempt_entity(cfs_rq->next, left) < 1)
+       se = cfs_rq->next;
+
+   clear_buddies(cfs_rq, se);
+
+   return se;
+}
+
+static void check_cfs_rq_runtime(struct cfs_rq *cfs_rq);
+
+static void put_prev_entity(struct cfs_rq *cfs_rq, struct sched_entity *prev)
+{
+   /*
+    * If still on the runqueue then deactivate_task()
+    * was not called and update_curr() has to be done:
+    */
+   if (prev->on_rq)
+       update_curr(cfs_rq);
+
+   /* throttle cfs_rqs exceeding runtime */
+   check_cfs_rq_runtime(cfs_rq);
+
+   check_spread(cfs_rq, prev);
+   if (prev->on_rq) {
+       update_stats_wait_start(cfs_rq, prev);
+       /* Put 'current' back into the tree. */
+       __enqueue_entity(cfs_rq, prev);
+   }
+   cfs_rq->curr = NULL;
+}
+
+static void
+entity_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr, int queued)
+{
+   /*
+    * Update run-time statistics of the 'current'.
+    */
+   update_curr(cfs_rq);
+
+   /*
+    * Update share accounting for long-running entities.
+    */
+   update_entity_shares_tick(cfs_rq);
+
+#ifdef CONFIG_SCHED_HRTICK
+   /*
+    * queued ticks are scheduled to match the slice, so don't bother
+    * validating it and just reschedule.
+    */
+   if (queued) {
+       resched_task(rq_of(cfs_rq)->curr);
+       return;
+   }
+   /*
+    * don't let the period tick interfere with the hrtick preemption
+    */
+   if (!sched_feat(DOUBLE_TICK) &&
+           hrtimer_active(&rq_of(cfs_rq)->hrtick_timer))
+       return;
+#endif
+
+   if (cfs_rq->nr_running > 1)
+       check_preempt_tick(cfs_rq, curr);
+}
+
+
+/**************************************************
+ * CFS bandwidth control machinery
+ */
+
+#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
+ */
+static inline u64 default_cfs_period(void)
+{
+   return 100000000ULL;
+}
+
+static inline u64 sched_cfs_bandwidth_slice(void)
+{
+   return (u64)sysctl_sched_cfs_bandwidth_slice * NSEC_PER_USEC;
+}
+
+/*
+ * Replenish runtime according to assigned quota and update expiration time.
+ * We use sched_clock_cpu directly instead of rq->clock to avoid adding
+ * additional synchronization around rq->lock.
+ *
+ * requires cfs_b->lock
+ */
+void __refill_cfs_bandwidth_runtime(struct cfs_bandwidth *cfs_b)
+{
+   u64 now;
+
+   if (cfs_b->quota == RUNTIME_INF)
+       return;
+
+   now = sched_clock_cpu(smp_processor_id());
+   cfs_b->runtime = cfs_b->quota;
+   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)
+{
+   struct task_group *tg = cfs_rq->tg;
+   struct cfs_bandwidth *cfs_b = tg_cfs_bandwidth(tg);
+   u64 amount = 0, min_amount, expires;
+
+   /* note: this is a positive sum as runtime_remaining <= 0 */
+   min_amount = sched_cfs_bandwidth_slice() - cfs_rq->runtime_remaining;
+
+   raw_spin_lock(&cfs_b->lock);
+   if (cfs_b->quota == RUNTIME_INF)
+       amount = min_amount;
+   else {
+       /*
+        * If the bandwidth pool has become inactive, then at least one
+        * period must have elapsed since the last consumption.
+        * Refresh the global state and ensure bandwidth timer becomes
+        * active.
+        */
+       if (!cfs_b->timer_active) {
+           __refill_cfs_bandwidth_runtime(cfs_b);
+           __start_cfs_bandwidth(cfs_b);
+       }
+
+       if (cfs_b->runtime > 0) {
+           amount = min(cfs_b->runtime, min_amount);
+           cfs_b->runtime -= amount;
+           cfs_b->idle = 0;
+       }
+   }
+   expires = cfs_b->runtime_expires;
+   raw_spin_unlock(&cfs_b->lock);
+
+   cfs_rq->runtime_remaining += amount;
+   /*
+    * we may have advanced our local expiration to account for allowed
+    * spread between our sched_clock and the one on which runtime was
+    * issued.
+    */
+   if ((s64)(expires - cfs_rq->runtime_expires) > 0)
+       cfs_rq->runtime_expires = expires;
+
+   return cfs_rq->runtime_remaining > 0;
+}
+
+/*
+ * Note: This depends on the synchronization provided by sched_clock and the
+ * fact that rq->clock snapshots this value.
+ */
+static void expire_cfs_rq_runtime(struct cfs_rq *cfs_rq)
+{
+   struct cfs_bandwidth *cfs_b = tg_cfs_bandwidth(cfs_rq->tg);
+   struct rq *rq = rq_of(cfs_rq);
+
+   /* if the deadline is ahead of our clock, nothing to do */
+   if (likely((s64)(rq->clock - cfs_rq->runtime_expires) < 0))
+       return;
+
+   if (cfs_rq->runtime_remaining < 0)
+       return;
+
+   /*
+    * If the local deadline has passed we have to consider the
+    * possibility that our sched_clock is 'fast' and the global deadline
+    * has not truly expired.
+    *
+    * Fortunately we can check determine whether this the case by checking
+    * whether the global deadline has advanced.
+    */
+
+   if ((s64)(cfs_rq->runtime_expires - cfs_b->runtime_expires) >= 0) {
+       /* extend local deadline, drift is bounded above by 2 ticks */
+       cfs_rq->runtime_expires += TICK_NSEC;
+   } else {
+       /* global deadline is ahead, expiration has passed */
+       cfs_rq->runtime_remaining = 0;
+   }
+}
+
+static void __account_cfs_rq_runtime(struct cfs_rq *cfs_rq,
+                    unsigned long delta_exec)
+{
+   /* dock delta_exec before expiring quota (as it could span periods) */
+   cfs_rq->runtime_remaining -= delta_exec;
+   expire_cfs_rq_runtime(cfs_rq);
+
+   if (likely(cfs_rq->runtime_remaining > 0))
+       return;
+
+   /*
+    * if we're unable to extend our runtime we resched so that the active
+    * hierarchy can be throttled
+    */
+   if (!assign_cfs_rq_runtime(cfs_rq) && likely(cfs_rq->curr))
+       resched_task(rq_of(cfs_rq)->curr);
+}
+
+static __always_inline void account_cfs_rq_runtime(struct cfs_rq *cfs_rq,
+                          unsigned long delta_exec)
+{
+   if (!cfs_bandwidth_used() || !cfs_rq->runtime_enabled)
+       return;
+
+   __account_cfs_rq_runtime(cfs_rq, delta_exec);
+}
+
+static inline int cfs_rq_throttled(struct cfs_rq *cfs_rq)
+{
+   return cfs_bandwidth_used() && cfs_rq->throttled;
+}
+
+/* check whether cfs_rq, or any parent, is throttled */
+static inline int throttled_hierarchy(struct cfs_rq *cfs_rq)
+{
+   return cfs_bandwidth_used() && cfs_rq->throttle_count;
+}
+
+/*
+ * Ensure that neither of the group entities corresponding to src_cpu or
+ * dest_cpu are members of a throttled hierarchy when performing group
+ * load-balance operations.
+ */
+static inline int throttled_lb_pair(struct task_group *tg,
+                   int src_cpu, int dest_cpu)
+{
+   struct cfs_rq *src_cfs_rq, *dest_cfs_rq;
+
+   src_cfs_rq = tg->cfs_rq[src_cpu];
+   dest_cfs_rq = tg->cfs_rq[dest_cpu];
+
+   return throttled_hierarchy(src_cfs_rq) ||
+          throttled_hierarchy(dest_cfs_rq);
+}
+
+/* updated child weight may affect parent so we have to do this bottom up */
+static int tg_unthrottle_up(struct task_group *tg, void *data)
+{
+   struct rq *rq = data;
+   struct cfs_rq *cfs_rq = tg->cfs_rq[cpu_of(rq)];
+
+   cfs_rq->throttle_count--;
+#ifdef CONFIG_SMP
+   if (!cfs_rq->throttle_count) {
+       u64 delta = rq->clock_task - cfs_rq->load_stamp;
+
+       /* leaving throttled state, advance shares averaging windows */
+       cfs_rq->load_stamp += delta;
+       cfs_rq->load_last += delta;
+
+       /* update entity weight now that we are on_rq again */
+       update_cfs_shares(cfs_rq);
+   }
+#endif
+
+   return 0;
+}
+
+static int tg_throttle_down(struct task_group *tg, void *data)
+{
+   struct rq *rq = data;
+   struct cfs_rq *cfs_rq = tg->cfs_rq[cpu_of(rq)];
+
+   /* group is entering throttled state, record last load */
+   if (!cfs_rq->throttle_count)
+       update_cfs_load(cfs_rq, 0);
+   cfs_rq->throttle_count++;
+
+   return 0;
+}
+
+static void throttle_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);
+   struct sched_entity *se;
+   long task_delta, dequeue = 1;
+
+   se = cfs_rq->tg->se[cpu_of(rq_of(cfs_rq))];
+
+   /* account load preceding throttle */
+   rcu_read_lock();
+   walk_tg_tree_from(cfs_rq->tg, tg_throttle_down, tg_nop, (void *)rq);
+   rcu_read_unlock();
+
+   task_delta = cfs_rq->h_nr_running;
+   for_each_sched_entity(se) {
+       struct cfs_rq *qcfs_rq = cfs_rq_of(se);
+       /* throttled entity or throttle-on-deactivate */
+       if (!se->on_rq)
+           break;
+
+       if (dequeue)
+           dequeue_entity(qcfs_rq, se, DEQUEUE_SLEEP);
+       qcfs_rq->h_nr_running -= task_delta;
+
+       if (qcfs_rq->load.weight)
+           dequeue = 0;
+   }
+
+   if (!se)
+       rq->nr_running -= task_delta;
+
+   cfs_rq->throttled = 1;
+   cfs_rq->throttled_timestamp = rq->clock;
+   raw_spin_lock(&cfs_b->lock);
+   list_add_tail_rcu(&cfs_rq->throttled_list, &cfs_b->throttled_cfs_rq);
+   raw_spin_unlock(&cfs_b->lock);
+}
+
+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);
+   struct sched_entity *se;
+   int enqueue = 1;
+   long task_delta;
+
+   se = cfs_rq->tg->se[cpu_of(rq_of(cfs_rq))];
+
+   cfs_rq->throttled = 0;
+   raw_spin_lock(&cfs_b->lock);
+   cfs_b->throttled_time += rq->clock - cfs_rq->throttled_timestamp;
+   list_del_rcu(&cfs_rq->throttled_list);
+   raw_spin_unlock(&cfs_b->lock);
+   cfs_rq->throttled_timestamp = 0;
+
+   update_rq_clock(rq);
+   /* update hierarchical throttle state */
+   walk_tg_tree_from(cfs_rq->tg, tg_nop, tg_unthrottle_up, (void *)rq);
+
+   if (!cfs_rq->load.weight)
+       return;
+
+   task_delta = cfs_rq->h_nr_running;
+   for_each_sched_entity(se) {
+       if (se->on_rq)
+           enqueue = 0;
+
+       cfs_rq = cfs_rq_of(se);
+       if (enqueue)
+           enqueue_entity(cfs_rq, se, ENQUEUE_WAKEUP);
+       cfs_rq->h_nr_running += task_delta;
+
+       if (cfs_rq_throttled(cfs_rq))
+           break;
+   }
+
+   if (!se)
+       rq->nr_running += task_delta;
+
+   /* determine whether we need to wake up potentially idle cpu */
+   if (rq->curr == rq->idle && rq->cfs.nr_running)
+       resched_task(rq->curr);
+}
+
+static u64 distribute_cfs_runtime(struct cfs_bandwidth *cfs_b,
+       u64 remaining, u64 expires)
+{
+   struct cfs_rq *cfs_rq;
+   u64 runtime = remaining;
+
+   rcu_read_lock();
+   list_for_each_entry_rcu(cfs_rq, &cfs_b->throttled_cfs_rq,
+               throttled_list) {
+       struct rq *rq = rq_of(cfs_rq);
+
+       raw_spin_lock(&rq->lock);
+       if (!cfs_rq_throttled(cfs_rq))
+           goto next;
+
+       runtime = -cfs_rq->runtime_remaining + 1;
+       if (runtime > remaining)
+           runtime = remaining;
+       remaining -= runtime;
+
+       cfs_rq->runtime_remaining += runtime;
+       cfs_rq->runtime_expires = expires;
+
+       /* we check whether we're throttled above */
+       if (cfs_rq->runtime_remaining > 0)
+           unthrottle_cfs_rq(cfs_rq);
+
+next:
+       raw_spin_unlock(&rq->lock);
+
+       if (!remaining)
+           break;
+   }
+   rcu_read_unlock();
+
+   return remaining;
+}
+
+/*
+ * Responsible for refilling a task_group's bandwidth and unthrottling its
+ * cfs_rqs as appropriate. If there has been no activity within the last
+ * period the timer is deactivated until scheduling resumes; cfs_b->idle is
+ * used to track this state.
+ */
+static int do_sched_cfs_period_timer(struct cfs_bandwidth *cfs_b, int overrun)
+{
+   u64 runtime, runtime_expires;
+   int idle = 1, throttled;
+
+   raw_spin_lock(&cfs_b->lock);
+   /* no need to continue the timer with no bandwidth constraint */
+   if (cfs_b->quota == RUNTIME_INF)
+       goto out_unlock;
+
+   throttled = !list_empty(&cfs_b->throttled_cfs_rq);
+   /* idle depends on !throttled (for the case of a large deficit) */
+   idle = cfs_b->idle && !throttled;
+   cfs_b->nr_periods += overrun;
+
+   /* if we're going inactive then everything else can be deferred */
+   if (idle)
+       goto out_unlock;
+
+   __refill_cfs_bandwidth_runtime(cfs_b);
+
+   if (!throttled) {
+       /* mark as potentially idle for the upcoming period */
+       cfs_b->idle = 1;
+       goto out_unlock;
+   }
+
+   /* account preceding periods in which throttling occurred */
+   cfs_b->nr_throttled += overrun;
+
+   /*
+    * There are throttled entities so we must first use the new bandwidth
+    * to unthrottle them before making it generally available.  This
+    * ensures that all existing debts will be paid before a new cfs_rq is
+    * allowed to run.
+    */
+   runtime = cfs_b->runtime;
+   runtime_expires = cfs_b->runtime_expires;
+   cfs_b->runtime = 0;
+
+   /*
+    * This check is repeated as we are holding onto the new bandwidth
+    * while we unthrottle.  This can potentially race with an unthrottled
+    * group trying to acquire new bandwidth from the global pool.
+    */
+   while (throttled && runtime > 0) {
+       raw_spin_unlock(&cfs_b->lock);
+       /* we can't nest cfs_b->lock while distributing bandwidth */
+       runtime = distribute_cfs_runtime(cfs_b, runtime,
+                        runtime_expires);
+       raw_spin_lock(&cfs_b->lock);
+
+       throttled = !list_empty(&cfs_b->throttled_cfs_rq);
+   }
+
+   /* return (any) remaining runtime */
+   cfs_b->runtime = runtime;
+   /*
+    * While we are ensured activity in the period following an
+    * unthrottle, this also covers the case in which the new bandwidth is
+    * insufficient to cover the existing bandwidth deficit.  (Forcing the
+    * timer to remain active while there are any throttled entities.)
+    */
+   cfs_b->idle = 0;
+out_unlock:
+   if (idle)
+       cfs_b->timer_active = 0;
+   raw_spin_unlock(&cfs_b->lock);
+
+   return idle;
+}
+
+/* a cfs_rq won't donate quota below this amount */
+static const u64 min_cfs_rq_runtime = 1 * NSEC_PER_MSEC;
+/* minimum remaining period time to redistribute slack quota */
+static const u64 min_bandwidth_expiration = 2 * NSEC_PER_MSEC;
+/* how long we wait to gather additional slack before distributing */
+static const u64 cfs_bandwidth_slack_period = 5 * NSEC_PER_MSEC;
+
+/* are we near the end of the current quota period? */
+static int runtime_refresh_within(struct cfs_bandwidth *cfs_b, u64 min_expire)
+{
+   struct hrtimer *refresh_timer = &cfs_b->period_timer;
+   u64 remaining;
+
+   /* if the call-back is running a quota refresh is already occurring */
+   if (hrtimer_callback_running(refresh_timer))
+       return 1;
+
+   /* is a quota refresh about to occur? */
+   remaining = ktime_to_ns(hrtimer_expires_remaining(refresh_timer));
+   if (remaining < min_expire)
+       return 1;
+
+   return 0;
+}
+
+static void start_cfs_slack_bandwidth(struct cfs_bandwidth *cfs_b)
+{
+   u64 min_left = cfs_bandwidth_slack_period + min_bandwidth_expiration;
+
+   /* if there's a quota refresh soon don't bother with slack */
+   if (runtime_refresh_within(cfs_b, min_left))
+       return;
+
+   start_bandwidth_timer(&cfs_b->slack_timer,
+               ns_to_ktime(cfs_bandwidth_slack_period));
+}
+
+/* we know any runtime found here is valid as update_curr() precedes return */
+static void __return_cfs_rq_runtime(struct cfs_rq *cfs_rq)
+{
+   struct cfs_bandwidth *cfs_b = tg_cfs_bandwidth(cfs_rq->tg);
+   s64 slack_runtime = cfs_rq->runtime_remaining - min_cfs_rq_runtime;
+
+   if (slack_runtime <= 0)
+       return;
+
+   raw_spin_lock(&cfs_b->lock);
+   if (cfs_b->quota != RUNTIME_INF &&
+       cfs_rq->runtime_expires == cfs_b->runtime_expires) {
+       cfs_b->runtime += slack_runtime;
+
+       /* we are under rq->lock, defer unthrottling using a timer */
+       if (cfs_b->runtime > sched_cfs_bandwidth_slice() &&
+           !list_empty(&cfs_b->throttled_cfs_rq))
+           start_cfs_slack_bandwidth(cfs_b);
+   }
+   raw_spin_unlock(&cfs_b->lock);
+
+   /* even if it's not valid for return we don't want to try again */
+   cfs_rq->runtime_remaining -= slack_runtime;
+}
+
+static __always_inline void return_cfs_rq_runtime(struct cfs_rq *cfs_rq)
+{
+   if (!cfs_bandwidth_used())
+       return;
+
+   if (!cfs_rq->runtime_enabled || cfs_rq->nr_running)
+       return;
+
+   __return_cfs_rq_runtime(cfs_rq);
+}
+
+/*
+ * This is done with a timer (instead of inline with bandwidth return) since
+ * it's necessary to juggle rq->locks to unthrottle their respective cfs_rqs.
+ */
+static void do_sched_cfs_slack_timer(struct cfs_bandwidth *cfs_b)
+{
+   u64 runtime = 0, slice = sched_cfs_bandwidth_slice();
+   u64 expires;
+
+   /* confirm we're still not at a refresh boundary */
+   if (runtime_refresh_within(cfs_b, min_bandwidth_expiration))
+       return;
+
+   raw_spin_lock(&cfs_b->lock);
+   if (cfs_b->quota != RUNTIME_INF && cfs_b->runtime > slice) {
+       runtime = cfs_b->runtime;
+       cfs_b->runtime = 0;
+   }
+   expires = cfs_b->runtime_expires;
+   raw_spin_unlock(&cfs_b->lock);
+
+   if (!runtime)
+       return;
+
+   runtime = distribute_cfs_runtime(cfs_b, runtime, expires);
+
+   raw_spin_lock(&cfs_b->lock);
+   if (expires == cfs_b->runtime_expires)
+       cfs_b->runtime = runtime;
+   raw_spin_unlock(&cfs_b->lock);
+}
+
+/*
+ * When a group wakes up we want to make sure that its quota is not already
+ * expired/exceeded, otherwise it may be allowed to steal additional ticks of
+ * runtime as update_curr() throttling can not not trigger until it's on-rq.
+ */
+static void check_enqueue_throttle(struct cfs_rq *cfs_rq)
+{
+   if (!cfs_bandwidth_used())
+       return;
+
+   /* an active group must be handled by the update_curr()->put() path */
+   if (!cfs_rq->runtime_enabled || cfs_rq->curr)
+       return;
+
+   /* ensure the group is not already throttled */
+   if (cfs_rq_throttled(cfs_rq))
+       return;
+
+   /* update runtime allocation */
+   account_cfs_rq_runtime(cfs_rq, 0);
+   if (cfs_rq->runtime_remaining <= 0)
+       throttle_cfs_rq(cfs_rq);
+}
+
+/* conditionally throttle active cfs_rq's from put_prev_entity() */
+static void check_cfs_rq_runtime(struct cfs_rq *cfs_rq)
+{
+   if (!cfs_bandwidth_used())
+       return;
+
+   if (likely(!cfs_rq->runtime_enabled || cfs_rq->runtime_remaining > 0))
+       return;
+
+   /*
+    * it's possible for a throttled entity to be forced into a running
+    * state (e.g. set_curr_task), in this case we're finished.
+    */
+   if (cfs_rq_throttled(cfs_rq))
+       return;
+
+   throttle_cfs_rq(cfs_rq);
+}
+
+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) {}
+static void check_enqueue_throttle(struct cfs_rq *cfs_rq) {}
+static void return_cfs_rq_runtime(struct cfs_rq *cfs_rq) {}
+
+static inline int cfs_rq_throttled(struct cfs_rq *cfs_rq)
+{
+   return 0;
+}
+
+static inline int throttled_hierarchy(struct cfs_rq *cfs_rq)
+{
+   return 0;
+}
+
+static inline int throttled_lb_pair(struct task_group *tg,
+                   int src_cpu, int dest_cpu)
+{
+   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:
+ */
+
+#ifdef CONFIG_SCHED_HRTICK
+static void hrtick_start_fair(struct rq *rq, struct task_struct *p)
+{
+   struct sched_entity *se = &p->se;
+   struct cfs_rq *cfs_rq = cfs_rq_of(se);
+
+   WARN_ON(task_rq(p) != rq);
+
+   if (cfs_rq->nr_running > 1) {
+       u64 slice = sched_slice(cfs_rq, se);
+       u64 ran = se->sum_exec_runtime - se->prev_sum_exec_runtime;
+       s64 delta = slice - ran;
+
+       if (delta < 0) {
+           if (rq->curr == p)
+               resched_task(p);
+           return;
+       }
+
+       /*
+        * Don't schedule slices shorter than 10000ns, that just
+        * doesn't make sense. Rely on vruntime for fairness.
+        */
+       if (rq->curr != p)
+           delta = max_t(s64, 10000LL, delta);
+
+       hrtick_start(rq, delta);
+   }
+}
+
+/*
+ * called from enqueue/dequeue and updates the hrtick when the
+ * current task is from our class and nr_running is low enough
+ * to matter.
+ */
+static void hrtick_update(struct rq *rq)
+{
+   struct task_struct *curr = rq->curr;
+
+   if (!hrtick_enabled(rq) || curr->sched_class != &fair_sched_class)
+       return;
+
+   if (cfs_rq_of(&curr->se)->nr_running < sched_nr_latency)
+       hrtick_start_fair(rq, curr);
+}
+#else /* !CONFIG_SCHED_HRTICK */
+static inline void
+hrtick_start_fair(struct rq *rq, struct task_struct *p)
+{
+}
+
+static inline void hrtick_update(struct rq *rq)
+{
+}
+#endif
+
+/*
+ * The enqueue_task method is called before nr_running is
+ * increased. Here we update the fair scheduling stats and
+ * then put the task into the rbtree:
+ */
+static void
+enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags)
+{
+   struct cfs_rq *cfs_rq;
+   struct sched_entity *se = &p->se;
+
+   for_each_sched_entity(se) {
+       if (se->on_rq)
+           break;
+       cfs_rq = cfs_rq_of(se);
+       enqueue_entity(cfs_rq, se, flags);
+
+       /*
+        * end evaluation on encountering a throttled cfs_rq
+        *
+        * note: in the case of encountering a throttled cfs_rq we will
+        * post the final h_nr_running increment below.
+       */
+       if (cfs_rq_throttled(cfs_rq))
+           break;
+       cfs_rq->h_nr_running++;
+
+       flags = ENQUEUE_WAKEUP;
+   }
+
+   for_each_sched_entity(se) {
+       cfs_rq = cfs_rq_of(se);
+       cfs_rq->h_nr_running++;
+
+       if (cfs_rq_throttled(cfs_rq))
+           break;
+
+       update_cfs_load(cfs_rq, 0);
+       update_cfs_shares(cfs_rq);
+   }
+
+   if (!se)
+       inc_nr_running(rq);
+   hrtick_update(rq);
+}
+
+static void set_next_buddy(struct sched_entity *se);
+
+/*
+ * The dequeue_task method is called before nr_running is
+ * decreased. We remove the task from the rbtree and
+ * update the fair scheduling stats:
+ */
+static void dequeue_task_fair(struct rq *rq, struct task_struct *p, int flags)
+{
+   struct cfs_rq *cfs_rq;
+   struct sched_entity *se = &p->se;
+   int task_sleep = flags & DEQUEUE_SLEEP;
+
+   for_each_sched_entity(se) {
+       cfs_rq = cfs_rq_of(se);
+       dequeue_entity(cfs_rq, se, flags);
+
+       /*
+        * end evaluation on encountering a throttled cfs_rq
+        *
+        * note: in the case of encountering a throttled cfs_rq we will
+        * post the final h_nr_running decrement below.
+       */
+       if (cfs_rq_throttled(cfs_rq))
+           break;
+       cfs_rq->h_nr_running--;
+
+       /* Don't dequeue parent if it has other entities besides us */
+       if (cfs_rq->load.weight) {
+           /*
+            * Bias pick_next to pick a task from this cfs_rq, as
+            * p is sleeping when it is within its sched_slice.
+            */
+           if (task_sleep && parent_entity(se))
+               set_next_buddy(parent_entity(se));
+
+           /* avoid re-evaluating load for this entity */
+           se = parent_entity(se);
+           break;
+       }
+       flags |= DEQUEUE_SLEEP;
+   }
+
+   for_each_sched_entity(se) {
+       cfs_rq = cfs_rq_of(se);
+       cfs_rq->h_nr_running--;
+
+       if (cfs_rq_throttled(cfs_rq))
+           break;
+
+       update_cfs_load(cfs_rq, 0);
+       update_cfs_shares(cfs_rq);
+   }
+
+   if (!se)
+       dec_nr_running(rq);
+   hrtick_update(rq);
+}
+
+#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)
+{
+   struct sched_entity *se = &p->se;
+   struct cfs_rq *cfs_rq = cfs_rq_of(se);
+   u64 min_vruntime;
+
+#ifndef CONFIG_64BIT
+   u64 min_vruntime_copy;
+
+   do {
+       min_vruntime_copy = cfs_rq->min_vruntime_copy;
+       smp_rmb();
+       min_vruntime = cfs_rq->min_vruntime;
+   } while (min_vruntime != min_vruntime_copy);
+#else
+   min_vruntime = cfs_rq->min_vruntime;
+#endif
+
+   se->vruntime -= min_vruntime;
+}
+
+#ifdef CONFIG_FAIR_GROUP_SCHED
+/*
+ * effective_load() calculates the load change as seen from the root_task_group
+ *
+ * Adding load to a group doesn't make a group heavier, but can cause movement
+ * of group shares between cpus. Assuming the shares were perfectly aligned one
+ * can calculate the shift in shares.
+ *
+ * Calculate the effective load difference if @wl is added (subtracted) to @tg
+ * on this @cpu and results in a total addition (subtraction) of @wg to the
+ * total group weight.
+ *
+ * Given a runqueue weight distribution (rw_i) we can compute a shares
+ * distribution (s_i) using:
+ *
+ *   s_i = rw_i / \Sum rw_j                        (1)
+ *
+ * Suppose we have 4 CPUs and our @tg is a direct child of the root group and
+ * has 7 equal weight tasks, distributed as below (rw_i), with the resulting
+ * shares distribution (s_i):
+ *
+ *   rw_i = {   2,   4,   1,   0 }
+ *   s_i  = { 2/7, 4/7, 1/7,   0 }
+ *
+ * As per wake_affine() we're interested in the load of two CPUs (the CPU the
+ * task used to run on and the CPU the waker is running on), we need to
+ * compute the effect of waking a task on either CPU and, in case of a sync
+ * wakeup, compute the effect of the current task going to sleep.
+ *
+ * So for a change of @wl to the local @cpu with an overall group weight change
+ * of @wl we can compute the new shares distribution (s'_i) using:
+ *
+ *   s'_i = (rw_i + @wl) / (@wg + \Sum rw_j)               (2)
+ *
+ * Suppose we're interested in CPUs 0 and 1, and want to compute the load
+ * differences in waking a task to CPU 0. The additional task changes the
+ * weight and shares distributions like:
+ *
+ *   rw'_i = {   3,   4,   1,   0 }
+ *   s'_i  = { 3/8, 4/8, 1/8,   0 }
+ *
+ * We can then compute the difference in effective weight by using:
+ *
+ *   dw_i = S * (s'_i - s_i)                       (3)
+ *
+ * Where 'S' is the group weight as seen by its parent.
+ *
+ * Therefore the effective change in loads on CPU 0 would be 5/56 (3/8 - 2/7)
+ * times the weight of the group. The effect on CPU 1 would be -4/56 (4/8 -
+ * 4/7) times the weight of the group.
+ */
+static long effective_load(struct task_group *tg, int cpu, long wl, long wg)
+{
+   struct sched_entity *se = tg->se[cpu];
+
+   if (!tg->parent)    /* the trivial, non-cgroup case */
+       return wl;
+
+   for_each_sched_entity(se) {
+       long w, W;
+
+       tg = se->my_q->tg;
+
+       /*
+        * W = @wg + \Sum rw_j
+        */
+       W = wg + calc_tg_weight(tg, se->my_q);
+
+       /*
+        * w = rw_i + @wl
+        */
+       w = se->my_q->load.weight + wl;
+
+       /*
+        * wl = S * s'_i; see (2)
+        */
+       if (W > 0 && w < W)
+           wl = (w * tg->shares) / W;
+       else
+           wl = tg->shares;
+
+       /*
+        * Per the above, wl is the new se->load.weight value; since
+        * those are clipped to [MIN_SHARES, ...) do so now. See
+        * calc_cfs_shares().
+        */
+       if (wl < MIN_SHARES)
+           wl = MIN_SHARES;
+
+       /*
+        * wl = dw_i = S * (s'_i - s_i); see (3)
+        */
+       wl -= se->load.weight;
+
+       /*
+        * Recursively apply this logic to all parent groups to compute
+        * the final effective load change on the root group. Since
+        * only the @tg group gets extra weight, all parent groups can
+        * only redistribute existing shares. @wl is the shift in shares
+        * resulting from this level per the above.
+        */
+       wg = 0;
+   }
+
+   return wl;
+}
+#else
+
+static inline unsigned long effective_load(struct task_group *tg, int cpu,
+       unsigned long wl, unsigned long wg)
+{
+   return wl;
+}
+
+#endif
+
+static int wake_affine(struct sched_domain *sd, struct task_struct *p, int sync)
+{
+   s64 this_load, load;
+   int idx, this_cpu, prev_cpu;
+   unsigned long tl_per_task;
+   struct task_group *tg;
+   unsigned long weight;
+   int balanced;
+
+   idx   = sd->wake_idx;
+   this_cpu  = smp_processor_id();
+   prev_cpu  = task_cpu(p);
+   load      = source_load(prev_cpu, idx);
+   this_load = target_load(this_cpu, idx);
+
+   /*
+    * If sync wakeup then subtract the (maximum possible)
+    * effect of the currently running task from the load
+    * of the current CPU:
+    */
+   if (sync) {
+       tg = task_group(current);
+       weight = current->se.load.weight;
+
+       this_load += effective_load(tg, this_cpu, -weight, -weight);
+       load += effective_load(tg, prev_cpu, 0, -weight);
+   }
+
+   tg = task_group(p);
+   weight = p->se.load.weight;
+
+   /*
+    * In low-load situations, where prev_cpu is idle and this_cpu is idle
+    * due to the sync cause above having dropped this_load to 0, we'll
+    * always have an imbalance, but there's really nothing you can do
+    * about that, so that's good too.
+    *
+    * Otherwise check if either cpus are near enough in load to allow this
+    * task to be woken on this_cpu.
+    */
+   if (this_load > 0) {
+       s64 this_eff_load, prev_eff_load;
+
+       this_eff_load = 100;
+       this_eff_load *= power_of(prev_cpu);
+       this_eff_load *= this_load +
+           effective_load(tg, this_cpu, weight, weight);
+
+       prev_eff_load = 100 + (sd->imbalance_pct - 100) / 2;
+       prev_eff_load *= power_of(this_cpu);
+       prev_eff_load *= load + effective_load(tg, prev_cpu, 0, weight);
+
+       balanced = this_eff_load <= prev_eff_load;
+   } else
+       balanced = true;
+
+   /*
+    * If the currently running task will sleep within
+    * a reasonable amount of time then attract this newly
+    * woken task:
+    */
+   if (sync && balanced)
+       return 1;
+
+   schedstat_inc(p, se.statistics.nr_wakeups_affine_attempts);
+   tl_per_task = cpu_avg_load_per_task(this_cpu);
+
+   if (balanced ||
+       (this_load <= load &&
+        this_load + target_load(prev_cpu, idx) <= tl_per_task)) {
+       /*
+        * This domain has SD_WAKE_AFFINE and
+        * p is cache cold in this domain, and
+        * there is no bad imbalance.
+        */
+       schedstat_inc(sd, ttwu_move_affine);
+       schedstat_inc(p, se.statistics.nr_wakeups_affine);
+
+       return 1;
+   }
+   return 0;
+}
+
+/*
+ * find_idlest_group finds and returns the least busy CPU group within the
+ * domain.
+ */
+static struct sched_group *
+find_idlest_group(struct sched_domain *sd, struct task_struct *p,
+         int this_cpu, int load_idx)
+{
+   struct sched_group *idlest = NULL, *group = sd->groups;
+   unsigned long min_load = ULONG_MAX, this_load = 0;
+   int imbalance = 100 + (sd->imbalance_pct-100)/2;
+
+   do {
+       unsigned long load, avg_load;
+       int local_group;
+       int i;
+
+       /* Skip over this group if it has no CPUs allowed */
+       if (!cpumask_intersects(sched_group_cpus(group),
+                   tsk_cpus_allowed(p)))
+           continue;
+
+       local_group = cpumask_test_cpu(this_cpu,
+                          sched_group_cpus(group));
+
+       /* Tally up the load of all CPUs in the group */
+       avg_load = 0;
+
+       for_each_cpu(i, sched_group_cpus(group)) {
+           /* Bias balancing toward cpus of our domain */
+           if (local_group)
+               load = source_load(i, load_idx);
+           else
+               load = target_load(i, load_idx);
+
+           avg_load += load;
+       }
+
+       /* Adjust by relative CPU power of the group */
+       avg_load = (avg_load * SCHED_POWER_SCALE) / group->sgp->power;
+
+       if (local_group) {
+           this_load = avg_load;
+       } else if (avg_load < min_load) {
+           min_load = avg_load;
+           idlest = group;
+       }
+   } while (group = group->next, group != sd->groups);
+
+   if (!idlest || 100*this_load < imbalance*min_load)
+       return NULL;
+   return idlest;
+}
+
+/*
+ * find_idlest_cpu - find the idlest cpu among the cpus in group.
+ */
+static int
+find_idlest_cpu(struct sched_group *group, struct task_struct *p, int this_cpu)
+{
+   unsigned long load, min_load = ULONG_MAX;
+   int idlest = -1;
+   int i;
+
+   /* Traverse only the allowed CPUs */
+   for_each_cpu_and(i, sched_group_cpus(group), tsk_cpus_allowed(p)) {
+       load = weighted_cpuload(i);
+
+       if (load < min_load || (load == min_load && i == this_cpu)) {
+           min_load = load;
+           idlest = i;
+       }
+   }
+
+   return idlest;
+}
+
+/*
+ * Try and locate an idle CPU in the sched_domain.
+ */
+static int select_idle_sibling(struct task_struct *p, int target)
+{
+   int cpu = smp_processor_id();
+   int prev_cpu = task_cpu(p);
+   struct sched_domain *sd;
+   struct sched_group *sg;
+   int i;
+
+   /*
+    * If the task is going to be woken-up on this cpu and if it is
+    * already idle, then it is the right target.
+    */
+   if (target == cpu && idle_cpu(cpu))
+       return cpu;
+
+   /*
+    * If the task is going to be woken-up on the cpu where it previously
+    * ran and if it is currently idle, then it the right target.
+    */
+   if (target == prev_cpu && idle_cpu(prev_cpu))
+       return prev_cpu;
+
+   /*
+    * Otherwise, iterate the domains and find an elegible idle cpu.
+    */
+   rcu_read_lock();
+
+   sd = rcu_dereference(per_cpu(sd_llc, target));
+   for_each_lower_domain(sd) {
+       sg = sd->groups;
+       do {
+           if (!cpumask_intersects(sched_group_cpus(sg),
+                       tsk_cpus_allowed(p)))
+               goto next;
+
+           for_each_cpu(i, sched_group_cpus(sg)) {
+               if (!idle_cpu(i))
+                   goto next;
+           }
+
+           target = cpumask_first_and(sched_group_cpus(sg),
+                   tsk_cpus_allowed(p));
+           goto done;
+next:
+           sg = sg->next;
+       } while (sg != sd->groups);
+   }
+done:
+   rcu_read_unlock();
+
+   return target;
+}
+
+/*
+ * sched_balance_self: balance the current task (running on cpu) in domains
+ * that have the 'flag' flag set. In practice, this is SD_BALANCE_FORK and
+ * SD_BALANCE_EXEC.
+ *
+ * Balance, ie. select the least loaded group.
+ *
+ * Returns the target CPU number, or the same CPU if no balancing is needed.
+ *
+ * preempt must be disabled.
+ */
+static int
+select_task_rq_fair(struct task_struct *p, int sd_flag, int wake_flags)
+{
+   struct sched_domain *tmp, *affine_sd = NULL, *sd = NULL;
+   int cpu = smp_processor_id();
+   int prev_cpu = task_cpu(p);
+   int new_cpu = cpu;
+   int want_affine = 0;
+   int want_sd = 1;
+   int sync = wake_flags & WF_SYNC;
+
+   if (p->rt.nr_cpus_allowed == 1)
+       return prev_cpu;
+
+   if (sd_flag & SD_BALANCE_WAKE) {
+       if (cpumask_test_cpu(cpu, tsk_cpus_allowed(p)))
+           want_affine = 1;
+       new_cpu = prev_cpu;
+   }
+
+   rcu_read_lock();
+   for_each_domain(cpu, tmp) {
+       if (!(tmp->flags & SD_LOAD_BALANCE))
+           continue;
+
+       /*
+        * If power savings logic is enabled for a domain, see if we
+        * are not overloaded, if so, don't balance wider.
+        */
+       if (tmp->flags & (SD_POWERSAVINGS_BALANCE|SD_PREFER_LOCAL)) {
+           unsigned long power = 0;
+           unsigned long nr_running = 0;
+           unsigned long capacity;
+           int i;
+
+           for_each_cpu(i, sched_domain_span(tmp)) {
+               power += power_of(i);
+               nr_running += cpu_rq(i)->cfs.nr_running;
+           }
+
+           capacity = DIV_ROUND_CLOSEST(power, SCHED_POWER_SCALE);
+
+           if (tmp->flags & SD_POWERSAVINGS_BALANCE)
+               nr_running /= 2;
+
+           if (nr_running < capacity)
+               want_sd = 0;
+       }
+
+       /*
+        * If both cpu and prev_cpu are part of this domain,
+        * cpu is a valid SD_WAKE_AFFINE target.
+        */
+       if (want_affine && (tmp->flags & SD_WAKE_AFFINE) &&
+           cpumask_test_cpu(prev_cpu, sched_domain_span(tmp))) {
+           affine_sd = tmp;
+           want_affine = 0;
+       }
+
+       if (!want_sd && !want_affine)
+           break;
+
+       if (!(tmp->flags & sd_flag))
+           continue;
+
+       if (want_sd)
+           sd = tmp;
+   }
+
+   if (affine_sd) {
+       if (cpu == prev_cpu || wake_affine(affine_sd, p, sync))
+           prev_cpu = cpu;
+
+       new_cpu = select_idle_sibling(p, prev_cpu);
+       goto unlock;
+   }
+
+   while (sd) {
+       int load_idx = sd->forkexec_idx;
+       struct sched_group *group;
+       int weight;
+
+       if (!(sd->flags & sd_flag)) {
+           sd = sd->child;
+           continue;
+       }
+
+       if (sd_flag & SD_BALANCE_WAKE)
+           load_idx = sd->wake_idx;
+
+       group = find_idlest_group(sd, p, cpu, load_idx);
+       if (!group) {
+           sd = sd->child;
+           continue;
+       }
+
+       new_cpu = find_idlest_cpu(group, p, cpu);
+       if (new_cpu == -1 || new_cpu == cpu) {
+           /* Now try balancing at a lower domain level of cpu */
+           sd = sd->child;
+           continue;
+       }
+
+       /* Now try balancing at a lower domain level of new_cpu */
+       cpu = new_cpu;
+       weight = sd->span_weight;
+       sd = NULL;
+       for_each_domain(cpu, tmp) {
+           if (weight <= tmp->span_weight)
+               break;
+           if (tmp->flags & sd_flag)
+               sd = tmp;
+       }
+       /* while loop will break here if sd == NULL */
+   }
+unlock:
+   rcu_read_unlock();
+
+   return new_cpu;
+}
+#endif /* CONFIG_SMP */
+
+static unsigned long
+wakeup_gran(struct sched_entity *curr, struct sched_entity *se)
+{
+   unsigned long gran = sysctl_sched_wakeup_granularity;
+
+   /*
+    * Since its curr running now, convert the gran from real-time
+    * to virtual-time in his units.
+    *
+    * By using 'se' instead of 'curr' we penalize light tasks, so
+    * they get preempted easier. That is, if 'se' < 'curr' then
+    * the resulting gran will be larger, therefore penalizing the
+    * lighter, if otoh 'se' > 'curr' then the resulting gran will
+    * be smaller, again penalizing the lighter task.
+    *
+    * This is especially important for buddies when the leftmost
+    * task is higher priority than the buddy.
+    */
+   return calc_delta_fair(gran, se);
+}
+
+/*
+ * Should 'se' preempt 'curr'.
+ *
+ *             |s1
+ *        |s2
+ *   |s3
+ *         g
+ *      |<--->|c
+ *
+ *  w(c, s1) = -1
+ *  w(c, s2) =  0
+ *  w(c, s3) =  1
+ *
+ */
+static int
+wakeup_preempt_entity(struct sched_entity *curr, struct sched_entity *se)
+{
+   s64 gran, vdiff = curr->vruntime - se->vruntime;
+
+   if (vdiff <= 0)
+       return -1;
+
+   gran = wakeup_gran(curr, se);
+   if (vdiff > gran)
+       return 1;
+
+   return 0;
+}
+
+static void set_last_buddy(struct sched_entity *se)
+{
+   if (entity_is_task(se) && unlikely(task_of(se)->policy == SCHED_IDLE))
+       return;
+
+   for_each_sched_entity(se)
+       cfs_rq_of(se)->last = se;
+}
+
+static void set_next_buddy(struct sched_entity *se)
+{
+   if (entity_is_task(se) && unlikely(task_of(se)->policy == SCHED_IDLE))
+       return;
+
+   for_each_sched_entity(se)
+       cfs_rq_of(se)->next = se;
+}
+
+static void set_skip_buddy(struct sched_entity *se)
+{
+   for_each_sched_entity(se)
+       cfs_rq_of(se)->skip = se;
+}
+
+/*
+ * Preempt the current task with a newly woken task if needed:
+ */
+static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int wake_flags)
+{
+   struct task_struct *curr = rq->curr;
+   struct sched_entity *se = &curr->se, *pse = &p->se;
+   struct cfs_rq *cfs_rq = task_cfs_rq(curr);
+   int scale = cfs_rq->nr_running >= sched_nr_latency;
+   int next_buddy_marked = 0;
+
+   if (unlikely(se == pse))
+       return;
+
+   /*
+    * This is possible from callers such as pull_task(), in which we
+    * unconditionally check_prempt_curr() after an enqueue (which may have
+    * lead to a throttle).  This both saves work and prevents false
+    * next-buddy nomination below.
+    */
+   if (unlikely(throttled_hierarchy(cfs_rq_of(pse))))
+       return;
+
+   if (sched_feat(NEXT_BUDDY) && scale && !(wake_flags & WF_FORK)) {
+       set_next_buddy(pse);
+       next_buddy_marked = 1;
+   }
+
+   /*
+    * We can come here with TIF_NEED_RESCHED already set from new task
+    * wake up path.
+    *
+    * Note: this also catches the edge-case of curr being in a throttled
+    * group (e.g. via set_curr_task), since update_curr() (in the
+    * enqueue of curr) will have resulted in resched being set.  This
+    * prevents us from potentially nominating it as a false LAST_BUDDY
+    * below.
+    */
+   if (test_tsk_need_resched(curr))
+       return;
+
+   /* Idle tasks are by definition preempted by non-idle tasks. */
+   if (unlikely(curr->policy == SCHED_IDLE) &&
+       likely(p->policy != SCHED_IDLE))
+       goto preempt;
+
+   /*
+    * Batch and idle tasks do not preempt non-idle tasks (their preemption
+    * is driven by the tick):
+    */
+   if (unlikely(p->policy != SCHED_NORMAL))
+       return;
+
+   find_matching_se(&se, &pse);
+   update_curr(cfs_rq_of(se));
+   BUG_ON(!pse);
+   if (wakeup_preempt_entity(se, pse) == 1) {
+       /*
+        * Bias pick_next to pick the sched entity that is
+        * triggering this preemption.
+        */
+       if (!next_buddy_marked)
+           set_next_buddy(pse);
+       goto preempt;
+   }
+
+   return;
+
+preempt:
+   resched_task(curr);
+   /*
+    * Only set the backward buddy when the current task is still
+    * on the rq. This can happen when a wakeup gets interleaved
+    * with schedule on the ->pre_schedule() or idle_balance()
+    * point, either of which can * drop the rq lock.
+    *
+    * Also, during early boot the idle thread is in the fair class,
+    * for obvious reasons its a bad idea to schedule back to it.
+    */
+   if (unlikely(!se->on_rq || curr == rq->idle))
+       return;
+
+   if (sched_feat(LAST_BUDDY) && scale && entity_is_task(se))
+       set_last_buddy(se);
+}
+
+static struct task_struct *pick_next_task_fair(struct rq *rq)
+{
+   struct task_struct *p;
+   struct cfs_rq *cfs_rq = &rq->cfs;
+   struct sched_entity *se;
+
+   if (!cfs_rq->nr_running)
+       return NULL;
+
+   do {
+       se = pick_next_entity(cfs_rq);
+       set_next_entity(cfs_rq, se);
+       cfs_rq = group_cfs_rq(se);
+   } while (cfs_rq);
+
+   p = task_of(se);
+   if (hrtick_enabled(rq))
+       hrtick_start_fair(rq, p);
+
+   return p;
+}
+
+/*
+ * Account for a descheduled task:
+ */
+static void put_prev_task_fair(struct rq *rq, struct task_struct *prev)
+{
+   struct sched_entity *se = &prev->se;
+   struct cfs_rq *cfs_rq;
+
+   for_each_sched_entity(se) {
+       cfs_rq = cfs_rq_of(se);
+       put_prev_entity(cfs_rq, se);
+   }
+}
+
+/*
+ * sched_yield() is very simple
+ *
+ * The magic of dealing with the ->skip buddy is in pick_next_entity.
+ */
+static void yield_task_fair(struct rq *rq)
+{
+   struct task_struct *curr = rq->curr;
+   struct cfs_rq *cfs_rq = task_cfs_rq(curr);
+   struct sched_entity *se = &curr->se;
+
+   /*
+    * Are we the only task in the tree?
+    */
+   if (unlikely(rq->nr_running == 1))
+       return;
+
+   clear_buddies(cfs_rq, se);
+
+   if (curr->policy != SCHED_BATCH) {
+       update_rq_clock(rq);
+       /*
+        * Update run-time statistics of the 'current'.
+        */
+       update_curr(cfs_rq);
+       /*
+        * Tell update_rq_clock() that we've just updated,
+        * so we don't do microscopic update in schedule()
+        * and double the fastpath cost.
+        */
+        rq->skip_clock_update = 1;
+   }
+
+   set_skip_buddy(se);
+}
+
+static bool yield_to_task_fair(struct rq *rq, struct task_struct *p, bool preempt)
+{
+   struct sched_entity *se = &p->se;
+
+   /* throttled hierarchies are not runnable */
+   if (!se->on_rq || throttled_hierarchy(cfs_rq_of(se)))
+       return false;
+
+   /* Tell the scheduler that we'd really like pse to run next. */
+   set_next_buddy(se);
+
+   yield_task_fair(rq);
+
+   return true;
+}
+
+#ifdef CONFIG_SMP
+/**************************************************
+ * Fair scheduling class load-balancing methods:
+ */
+
+/*
+ * pull_task - move a task from a remote runqueue to the local runqueue.
+ * Both runqueues must be locked.
+ */
+static void pull_task(struct rq *src_rq, struct task_struct *p,
+             struct rq *this_rq, int this_cpu)
+{
+   deactivate_task(src_rq, p, 0);
+   set_task_cpu(p, this_cpu);
+   activate_task(this_rq, p, 0);
+   check_preempt_curr(this_rq, p, 0);
+}
+
+/*
+ * 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;
+}
+
+#define LBF_ALL_PINNED 0x01
+#define LBF_NEED_BREAK 0x02    /* clears into HAD_BREAK */
+#define LBF_HAD_BREAK  0x04
+#define LBF_HAD_BREAKS 0x0C    /* count HAD_BREAKs overflows into ABORT */
+#define LBF_ABORT  0x10
+
+/*
+ * can_migrate_task - may task p from runqueue rq be migrated to this_cpu?
+ */
+static
+int can_migrate_task(struct task_struct *p, struct rq *rq, int this_cpu,
+            struct sched_domain *sd, enum cpu_idle_type idle,
+            int *lb_flags)
+{
+   int tsk_cache_hot = 0;
+   /*
+    * We do not migrate tasks that are:
+    * 1) running (obviously), or
+    * 2) cannot be migrated to this CPU due to cpus_allowed, or
+    * 3) are cache-hot on their current CPU.
+    */
+   if (!cpumask_test_cpu(this_cpu, tsk_cpus_allowed(p))) {
+       schedstat_inc(p, se.statistics.nr_failed_migrations_affine);
+       return 0;
+   }
+   *lb_flags &= ~LBF_ALL_PINNED;
+
+   if (task_running(rq, p)) {
+       schedstat_inc(p, se.statistics.nr_failed_migrations_running);
+       return 0;
+   }
+
+   /*
+    * Aggressive migration if:
+    * 1) task is cache cold, or
+    * 2) too many balance attempts have failed.
+    */
+
+   tsk_cache_hot = task_hot(p, rq->clock_task, sd);
+   if (!tsk_cache_hot ||
+       sd->nr_balance_failed > sd->cache_nice_tries) {
+#ifdef CONFIG_SCHEDSTATS
+       if (tsk_cache_hot) {
+           schedstat_inc(sd, lb_hot_gained[idle]);
+           schedstat_inc(p, se.statistics.nr_forced_migrations);
+       }
+#endif
+       return 1;
+   }
+
+   if (tsk_cache_hot) {
+       schedstat_inc(p, se.statistics.nr_failed_migrations_hot);
+       return 0;
+   }
+   return 1;
+}
+
+/*
+ * move_one_task tries to move exactly one task from busiest to this_rq, as
+ * part of active balancing operations within "domain".
+ * Returns 1 if successful and 0 otherwise.
+ *
+ * Called with both runqueues locked.
+ */
+static int
+move_one_task(struct rq *this_rq, int this_cpu, struct rq *busiest,
+         struct sched_domain *sd, enum cpu_idle_type idle)
+{
+   struct task_struct *p, *n;
+   struct cfs_rq *cfs_rq;
+   int pinned = 0;
+
+   for_each_leaf_cfs_rq(busiest, cfs_rq) {
+       list_for_each_entry_safe(p, n, &cfs_rq->tasks, se.group_node) {
+           if (throttled_lb_pair(task_group(p),
+                         busiest->cpu, this_cpu))
+               break;
+
+           if (!can_migrate_task(p, busiest, this_cpu,
+                       sd, idle, &pinned))
+               continue;
+
+           pull_task(busiest, p, this_rq, this_cpu);
+           /*
+            * Right now, this is only the second place pull_task()
+            * is called, so we can safely collect pull_task()
+            * stats here rather than inside pull_task().
+            */
+           schedstat_inc(sd, lb_gained[idle]);
+           return 1;
+       }
+   }
+
+   return 0;
+}
+
+static unsigned long
+balance_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest,
+         unsigned long max_load_move, struct sched_domain *sd,
+         enum cpu_idle_type idle, int *lb_flags,
+         struct cfs_rq *busiest_cfs_rq)
+{
+   int loops = 0, pulled = 0;
+   long rem_load_move = max_load_move;
+   struct task_struct *p, *n;
+
+   if (max_load_move == 0)
+       goto out;
+
+   list_for_each_entry_safe(p, n, &busiest_cfs_rq->tasks, se.group_node) {
+       if (loops++ > sysctl_sched_nr_migrate) {
+           *lb_flags |= LBF_NEED_BREAK;
+           break;
+       }
+
+       if ((p->se.load.weight >> 1) > rem_load_move ||
+           !can_migrate_task(p, busiest, this_cpu, sd, idle,
+                     lb_flags))
+           continue;
+
+       pull_task(busiest, p, this_rq, this_cpu);
+       pulled++;
+       rem_load_move -= p->se.load.weight;
+
+#ifdef CONFIG_PREEMPT
+       /*
+        * NEWIDLE balancing is a source of latency, so preemptible
+        * kernels will stop after the first task is pulled to minimize
+        * the critical section.
+        */
+       if (idle == CPU_NEWLY_IDLE) {
+           *lb_flags |= LBF_ABORT;
+           break;
+       }
+#endif
+
+       /*
+        * We only want to steal up to the prescribed amount of
+        * weighted load.
+        */
+       if (rem_load_move <= 0)
+           break;
+   }
+out:
+   /*
+    * Right now, this is one of only two places pull_task() is called,
+    * so we can safely collect pull_task() stats here rather than
+    * inside pull_task().
+    */
+   schedstat_add(sd, lb_gained[idle], pulled);
+
+   return max_load_move - rem_load_move;
+}
+
+#ifdef CONFIG_FAIR_GROUP_SCHED
+/*
+ * update tg->load_weight by folding this cpu's load_avg
+ */
+static int update_shares_cpu(struct task_group *tg, int cpu)
+{
+   struct cfs_rq *cfs_rq;
+   unsigned long flags;
+   struct rq *rq;
+
+   if (!tg->se[cpu])
+       return 0;
+
+   rq = cpu_rq(cpu);
+   cfs_rq = tg->cfs_rq[cpu];
+
+   raw_spin_lock_irqsave(&rq->lock, flags);
+
+   update_rq_clock(rq);
+   update_cfs_load(cfs_rq, 1);
+
+   /*
+    * We need to update shares after updating tg->load_weight in
+    * order to adjust the weight of groups with long running tasks.
+    */
+   update_cfs_shares(cfs_rq);
+
+   raw_spin_unlock_irqrestore(&rq->lock, flags);
+
+   return 0;
+}
+
+static void update_shares(int cpu)
+{
+   struct cfs_rq *cfs_rq;
+   struct rq *rq = cpu_rq(cpu);
+
+   rcu_read_lock();
+   /*
+    * Iterates the task_group tree in a bottom up fashion, see
+    * list_add_leaf_cfs_rq() for details.
+    */
+   for_each_leaf_cfs_rq(rq, cfs_rq) {
+       /* throttled entities do not contribute to load */
+       if (throttled_hierarchy(cfs_rq))
+           continue;
+
+       update_shares_cpu(cfs_rq->tg, cpu);
+   }
+   rcu_read_unlock();
+}
+
+/*
+ * Compute the cpu's hierarchical load factor for each task group.
+ * This needs to be done in a top-down fashion because the load of a child
+ * group is a fraction of its parents load.
+ */
+static int tg_load_down(struct task_group *tg, void *data)
+{
+   unsigned long load;
+   long cpu = (long)data;
+
+   if (!tg->parent) {
+       load = cpu_rq(cpu)->load.weight;
+   } else {
+       load = tg->parent->cfs_rq[cpu]->h_load;
+       load *= tg->se[cpu]->load.weight;
+       load /= tg->parent->cfs_rq[cpu]->load.weight + 1;
+   }
+
+   tg->cfs_rq[cpu]->h_load = load;
+
+   return 0;
+}
+
+static void update_h_load(long cpu)
+{
+   walk_tg_tree(tg_load_down, tg_nop, (void *)cpu);
+}
+
+static unsigned long
+load_balance_fair(struct rq *this_rq, int this_cpu, struct rq *busiest,
+         unsigned long max_load_move,
+         struct sched_domain *sd, enum cpu_idle_type idle,
+         int *lb_flags)
+{
+   long rem_load_move = max_load_move;
+   struct cfs_rq *busiest_cfs_rq;
+
+   rcu_read_lock();
+   update_h_load(cpu_of(busiest));
+
+   for_each_leaf_cfs_rq(busiest, busiest_cfs_rq) {
+       unsigned long busiest_h_load = busiest_cfs_rq->h_load;
+       unsigned long busiest_weight = busiest_cfs_rq->load.weight;
+       u64 rem_load, moved_load;
+
+       if (*lb_flags & (LBF_NEED_BREAK|LBF_ABORT))
+           break;
+
+       /*
+        * empty group or part of a throttled hierarchy
+        */
+       if (!busiest_cfs_rq->task_weight ||
+           throttled_lb_pair(busiest_cfs_rq->tg, cpu_of(busiest), this_cpu))
+           continue;
+
+       rem_load = (u64)rem_load_move * busiest_weight;
+       rem_load = div_u64(rem_load, busiest_h_load + 1);
+
+       moved_load = balance_tasks(this_rq, this_cpu, busiest,
+               rem_load, sd, idle, lb_flags,
+               busiest_cfs_rq);
+
+       if (!moved_load)
+           continue;
+
+       moved_load *= busiest_h_load;
+       moved_load = div_u64(moved_load, busiest_weight + 1);
+
+       rem_load_move -= moved_load;
+       if (rem_load_move < 0)
+           break;
+   }
+   rcu_read_unlock();
+
+   return max_load_move - rem_load_move;
+}
+#else
+static inline void update_shares(int cpu)
+{
+}
+
+static unsigned long
+load_balance_fair(struct rq *this_rq, int this_cpu, struct rq *busiest,
+         unsigned long max_load_move,
+         struct sched_domain *sd, enum cpu_idle_type idle,
+         int *lb_flags)
+{
+   return balance_tasks(this_rq, this_cpu, busiest,
+           max_load_move, sd, idle, lb_flags,
+           &busiest->cfs);
+}
+#endif
+
+/*
+ * move_tasks tries to move up to max_load_move weighted load from busiest to
+ * this_rq, as part of a balancing operation within domain "sd".
+ * Returns 1 if successful and 0 otherwise.
+ *
+ * Called with both runqueues locked.
+ */
+static int move_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest,
+             unsigned long max_load_move,
+             struct sched_domain *sd, enum cpu_idle_type idle,
+             int *lb_flags)
+{
+   unsigned long total_load_moved = 0, load_moved;
+
+   do {
+       load_moved = load_balance_fair(this_rq, this_cpu, busiest,
+               max_load_move - total_load_moved,
+               sd, idle, lb_flags);
+
+       total_load_moved += load_moved;
+
+       if (*lb_flags & (LBF_NEED_BREAK|LBF_ABORT))
+           break;
+
+#ifdef CONFIG_PREEMPT
+       /*
+        * NEWIDLE balancing is a source of latency, so preemptible
+        * kernels will stop after the first task is pulled to minimize
+        * the critical section.
+        */
+       if (idle == CPU_NEWLY_IDLE && this_rq->nr_running) {
+           *lb_flags |= LBF_ABORT;
+           break;
+       }
+#endif
+   } while (load_moved && max_load_move > total_load_moved);
+
+   return total_load_moved > 0;
+}
+
+/********** Helpers for find_busiest_group ************************/
+/*
+ * sd_lb_stats - Structure to store the statistics of a sched_domain
+ *         during load balancing.
+ */
+struct sd_lb_stats {
+   struct sched_group *busiest; /* Busiest group in this sd */
+   struct sched_group *this;  /* Local group in this sd */
+   unsigned long total_load;  /* Total load of all groups in sd */
+   unsigned long total_pwr;   /*   Total power of all groups in sd */
+   unsigned long avg_load;    /* Average load across all groups in sd */
+
+   /** Statistics of this group */
+   unsigned long this_load;
+   unsigned long this_load_per_task;
+   unsigned long this_nr_running;
+   unsigned long this_has_capacity;
+   unsigned int  this_idle_cpus;
+
+   /* Statistics of the busiest group */
+   unsigned int  busiest_idle_cpus;
+   unsigned long max_load;
+   unsigned long busiest_load_per_task;
+   unsigned long busiest_nr_running;
+   unsigned long busiest_group_capacity;
+   unsigned long busiest_has_capacity;
+   unsigned int  busiest_group_weight;
+
+   int group_imb; /* Is there imbalance in this sd */
+#if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT)
+   int power_savings_balance; /* Is powersave balance needed for this sd */
+   struct sched_group *group_min; /* Least loaded group in sd */
+   struct sched_group *group_leader; /* Group which relieves group_min */
+   unsigned long min_load_per_task; /* load_per_task in group_min */
+   unsigned long leader_nr_running; /* Nr running of group_leader */
+   unsigned long min_nr_running; /* Nr running of group_min */
+#endif
+};
+
+/*
+ * sg_lb_stats - stats of a sched_group required for load_balancing
+ */
+struct sg_lb_stats {
+   unsigned long avg_load; /*Avg load across the CPUs of the group */
+   unsigned long group_load; /* Total load over the CPUs of the group */
+   unsigned long sum_nr_running; /* Nr tasks running in the group */
+   unsigned long sum_weighted_load; /* Weighted load of group's tasks */
+   unsigned long group_capacity;
+   unsigned long idle_cpus;
+   unsigned long group_weight;
+   int group_imb; /* Is there an imbalance in the group ? */
+   int group_has_capacity; /* Is there extra capacity in the 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.
+ */
+static inline int get_sd_load_idx(struct sched_domain *sd,
+                   enum cpu_idle_type idle)
+{
+   int load_idx;
+
+   switch (idle) {
+   case CPU_NOT_IDLE:
+       load_idx = sd->busy_idx;
+       break;
+
+   case CPU_NEWLY_IDLE:
+       load_idx = sd->newidle_idx;
+       break;
+   default:
+       load_idx = sd->idle_idx;
+       break;
+   }
+
+   return load_idx;
+}
+
+
+#if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT)
+/**
+ * init_sd_power_savings_stats - Initialize power savings statistics for
+ * the given sched_domain, during load balancing.
+ *
+ * @sd: Sched domain whose power-savings statistics are to be initialized.
+ * @sds: Variable containing the statistics for sd.
+ * @idle: Idle status of the CPU at which we're performing load-balancing.
+ */
+static inline void init_sd_power_savings_stats(struct sched_domain *sd,
+   struct sd_lb_stats *sds, enum cpu_idle_type idle)
+{
+   /*
+    * Busy processors will not participate in power savings
+    * balance.
+    */
+   if (idle == CPU_NOT_IDLE || !(sd->flags & SD_POWERSAVINGS_BALANCE))
+       sds->power_savings_balance = 0;
+   else {
+       sds->power_savings_balance = 1;
+       sds->min_nr_running = ULONG_MAX;
+       sds->leader_nr_running = 0;
+   }
+}
+
+/**
+ * update_sd_power_savings_stats - Update the power saving stats for a
+ * sched_domain while performing load balancing.
+ *
+ * @group: sched_group belonging to the sched_domain under consideration.
+ * @sds: Variable containing the statistics of the sched_domain
+ * @local_group: Does group contain the CPU for which we're performing
+ *         load balancing ?
+ * @sgs: Variable containing the statistics of the group.
+ */
+static inline void update_sd_power_savings_stats(struct sched_group *group,
+   struct sd_lb_stats *sds, int local_group, struct sg_lb_stats *sgs)
+{
+
+   if (!sds->power_savings_balance)
+       return;
+
+   /*
+    * If the local group is idle or completely loaded
+    * no need to do power savings balance at this domain
+    */
+   if (local_group && (sds->this_nr_running >= sgs->group_capacity ||
+               !sds->this_nr_running))
+       sds->power_savings_balance = 0;
+
+   /*
+    * If a group is already running at full capacity or idle,
+    * don't include that group in power savings calculations
+    */
+   if (!sds->power_savings_balance ||
+       sgs->sum_nr_running >= sgs->group_capacity ||
+       !sgs->sum_nr_running)
+       return;
+
+   /*
+    * Calculate the group which has the least non-idle load.
+    * This is the group from where we need to pick up the load
+    * for saving power
+    */
+   if ((sgs->sum_nr_running < sds->min_nr_running) ||
+       (sgs->sum_nr_running == sds->min_nr_running &&
+        group_first_cpu(group) > group_first_cpu(sds->group_min))) {
+       sds->group_min = group;
+       sds->min_nr_running = sgs->sum_nr_running;
+       sds->min_load_per_task = sgs->sum_weighted_load /
+                       sgs->sum_nr_running;
+   }
+
+   /*
+    * Calculate the group which is almost near its
+    * capacity but still has some space to pick up some load
+    * from other group and save more power
+    */
+   if (sgs->sum_nr_running + 1 > sgs->group_capacity)
+       return;
+
+   if (sgs->sum_nr_running > sds->leader_nr_running ||
+       (sgs->sum_nr_running == sds->leader_nr_running &&
+        group_first_cpu(group) < group_first_cpu(sds->group_leader))) {
+       sds->group_leader = group;
+       sds->leader_nr_running = sgs->sum_nr_running;
+   }
+}
+
+/**
+ * check_power_save_busiest_group - see if there is potential for some power-savings balance
+ * @sds: Variable containing the statistics of the sched_domain
+ * under consideration.
+ * @this_cpu: Cpu at which we're currently performing load-balancing.
+ * @imbalance: Variable to store the imbalance.
+ *
+ * Description:
+ * Check if we have potential to perform some power-savings balance.
+ * If yes, set the busiest group to be the least loaded group in the
+ * sched_domain, so that it's CPUs can be put to idle.
+ *
+ * Returns 1 if there is potential to perform power-savings balance.
+ * Else returns 0.
+ */
+static inline int check_power_save_busiest_group(struct sd_lb_stats *sds,
+                   int this_cpu, unsigned long *imbalance)
+{
+   if (!sds->power_savings_balance)
+       return 0;
+
+   if (sds->this != sds->group_leader ||
+           sds->group_leader == sds->group_min)
+       return 0;
+
+   *imbalance = sds->min_load_per_task;
+   sds->busiest = sds->group_min;
+
+   return 1;
+
+}
+#else /* CONFIG_SCHED_MC || CONFIG_SCHED_SMT */
+static inline void init_sd_power_savings_stats(struct sched_domain *sd,
+   struct sd_lb_stats *sds, enum cpu_idle_type idle)
+{
+   return;
+}
+
+static inline void update_sd_power_savings_stats(struct sched_group *group,
+   struct sd_lb_stats *sds, int local_group, struct sg_lb_stats *sgs)
+{
+   return;
+}
+
+static inline int check_power_save_busiest_group(struct sd_lb_stats *sds,
+                   int this_cpu, unsigned long *imbalance)
+{
+   return 0;
+}
+#endif /* CONFIG_SCHED_MC || CONFIG_SCHED_SMT */
+
+
+unsigned long default_scale_freq_power(struct sched_domain *sd, int cpu)
+{
+   return SCHED_POWER_SCALE;
+}
+
+unsigned long __weak arch_scale_freq_power(struct sched_domain *sd, int cpu)
+{
+   return default_scale_freq_power(sd, cpu);
+}
+
+unsigned long default_scale_smt_power(struct sched_domain *sd, int cpu)
+{
+   unsigned long weight = sd->span_weight;
+   unsigned long smt_gain = sd->smt_gain;
+
+   smt_gain /= weight;
+
+   return smt_gain;
+}
+
+unsigned long __weak arch_scale_smt_power(struct sched_domain *sd, int cpu)
+{
+   return default_scale_smt_power(sd, cpu);
+}
+
+unsigned long scale_rt_power(int cpu)
+{
+   struct rq *rq = cpu_rq(cpu);
+   u64 total, available;
+
+   total = sched_avg_period() + (rq->clock - rq->age_stamp);
+
+   if (unlikely(total < rq->rt_avg)) {
+       /* Ensures that power won't end up being negative */
+       available = 0;
+   } else {
+       available = total - rq->rt_avg;
+   }
+
+   if (unlikely((s64)total < SCHED_POWER_SCALE))
+       total = SCHED_POWER_SCALE;
+
+   total >>= SCHED_POWER_SHIFT;
+
+   return div_u64(available, total);
+}
+
+static void update_cpu_power(struct sched_domain *sd, int cpu)
+{
+   unsigned long weight = sd->span_weight;
+   unsigned long power = SCHED_POWER_SCALE;
+   struct sched_group *sdg = sd->groups;
+
+   if ((sd->flags & SD_SHARE_CPUPOWER) && weight > 1) {
+       if (sched_feat(ARCH_POWER))
+           power *= arch_scale_smt_power(sd, cpu);
+       else
+           power *= default_scale_smt_power(sd, cpu);
+
+       power >>= SCHED_POWER_SHIFT;
+   }
+
+   sdg->sgp->power_orig = power;
+
+   if (sched_feat(ARCH_POWER))
+       power *= arch_scale_freq_power(sd, cpu);
+   else
+       power *= default_scale_freq_power(sd, cpu);
+
+   power >>= SCHED_POWER_SHIFT;
+
+   power *= scale_rt_power(cpu);
+   power >>= SCHED_POWER_SHIFT;
+
+   if (!power)
+       power = 1;
+
+   cpu_rq(cpu)->cpu_power = power;
+   sdg->sgp->power = power;
+}
+
+void update_group_power(struct sched_domain *sd, int cpu)
+{
+   struct sched_domain *child = sd->child;
+   struct sched_group *group, *sdg = sd->groups;
+   unsigned long power;
+
+   if (!child) {
+       update_cpu_power(sd, cpu);
+       return;
+   }
+
+   power = 0;
+
+   group = child->groups;
+   do {
+       power += group->sgp->power;
+       group = group->next;
+   } while (group != child->groups);
+
+   sdg->sgp->power = power;
+}
+
+/*
+ * Try and fix up capacity for tiny siblings, this is needed when
+ * things like SD_ASYM_PACKING need f_b_g to select another sibling
+ * which on its own isn't powerful enough.
+ *
+ * See update_sd_pick_busiest() and check_asym_packing().
+ */
+static inline int
+fix_small_capacity(struct sched_domain *sd, struct sched_group *group)
+{
+   /*
+    * Only siblings can have significantly less than SCHED_POWER_SCALE
+    */
+   if (!(sd->flags & SD_SHARE_CPUPOWER))
+       return 0;
+
+   /*
+    * If ~90% of the cpu_power is still there, we're good.
+    */
+   if (group->sgp->power * 32 > group->sgp->power_orig * 29)
+       return 1;
+
+   return 0;
+}
+
+/**
+ * update_sg_lb_stats - Update sched_group's statistics for load balancing.
+ * @sd: The sched_domain whose statistics are to be updated.
+ * @group: sched_group whose statistics are to be updated.
+ * @this_cpu: Cpu for which load balance is currently performed.
+ * @idle: Idle status of this_cpu
+ * @load_idx: Load index of sched_domain of this_cpu for load calc.
+ * @local_group: Does group contain this_cpu.
+ * @cpus: Set of cpus considered for load balancing.
+ * @balance: Should we balance.
+ * @sgs: variable to hold the statistics for this group.
+ */
+static inline void update_sg_lb_stats(struct sched_domain *sd,
+           struct sched_group *group, int this_cpu,
+           enum cpu_idle_type idle, int load_idx,
+           int local_group, const struct cpumask *cpus,
+           int *balance, struct sg_lb_stats *sgs)
+{
+   unsigned long load, max_cpu_load, min_cpu_load, max_nr_running;
+   int i;
+   unsigned int balance_cpu = -1, first_idle_cpu = 0;
+   unsigned long avg_load_per_task = 0;
+
+   if (local_group)
+       balance_cpu = group_first_cpu(group);
+
+   /* Tally up the load of all CPUs in the group */
+   max_cpu_load = 0;
+   min_cpu_load = ~0UL;
+   max_nr_running = 0;
+
+   for_each_cpu_and(i, sched_group_cpus(group), cpus) {
+       struct rq *rq = cpu_rq(i);
+
+       /* Bias balancing toward cpus of our domain */
+       if (local_group) {
+           if (idle_cpu(i) && !first_idle_cpu) {
+               first_idle_cpu = 1;
+               balance_cpu = i;
+           }
+
+           load = target_load(i, load_idx);
+       } else {
+           load = source_load(i, load_idx);
+           if (load > max_cpu_load) {
+               max_cpu_load = load;
+               max_nr_running = rq->nr_running;
+           }
+           if (min_cpu_load > load)
+               min_cpu_load = load;
+       }
+
+       sgs->group_load += load;
+       sgs->sum_nr_running += rq->nr_running;
+       sgs->sum_weighted_load += weighted_cpuload(i);
+       if (idle_cpu(i))
+           sgs->idle_cpus++;
+   }
+
+   /*
+    * First idle cpu or the first cpu(busiest) in this sched group
+    * is eligible for doing load balancing at this and above
+    * domains. In the newly idle case, we will allow all the cpu's
+    * to do the newly idle load balance.
+    */
+   if (idle != CPU_NEWLY_IDLE && local_group) {
+       if (balance_cpu != this_cpu) {
+           *balance = 0;
+           return;
+       }
+       update_group_power(sd, this_cpu);
+   }
+
+   /* Adjust by relative CPU power of the group */
+   sgs->avg_load = (sgs->group_load*SCHED_POWER_SCALE) / group->sgp->power;
+
+   /*
+    * Consider the group unbalanced when the imbalance is larger
+    * than the average weight of a task.
+    *
+    * APZ: with cgroup the avg task weight can vary wildly and
+    *      might not be a suitable number - should we keep a
+    *      normalized nr_running number somewhere that negates
+    *      the hierarchy?
+    */
+   if (sgs->sum_nr_running)
+       avg_load_per_task = sgs->sum_weighted_load / sgs->sum_nr_running;
+
+   if ((max_cpu_load - min_cpu_load) >= avg_load_per_task && max_nr_running > 1)
+       sgs->group_imb = 1;
+
+   sgs->group_capacity = DIV_ROUND_CLOSEST(group->sgp->power,
+                       SCHED_POWER_SCALE);
+   if (!sgs->group_capacity)
+       sgs->group_capacity = fix_small_capacity(sd, group);
+   sgs->group_weight = group->group_weight;
+
+   if (sgs->group_capacity > sgs->sum_nr_running)
+       sgs->group_has_capacity = 1;
+}
+
+/**
+ * update_sd_pick_busiest - return 1 on busiest group
+ * @sd: sched_domain whose statistics are to be checked
+ * @sds: sched_domain statistics
+ * @sg: sched_group candidate to be checked for being the busiest
+ * @sgs: sched_group statistics
+ * @this_cpu: the current cpu
+ *
+ * Determine if @sg is a busier group than the previously selected
+ * busiest group.
+ */
+static bool update_sd_pick_busiest(struct sched_domain *sd,
+                  struct sd_lb_stats *sds,
+                  struct sched_group *sg,
+                  struct sg_lb_stats *sgs,
+                  int this_cpu)
+{
+   if (sgs->avg_load <= sds->max_load)
+       return false;
+
+   if (sgs->sum_nr_running > sgs->group_capacity)
+       return true;
+
+   if (sgs->group_imb)
+       return true;
+
+   /*
+    * ASYM_PACKING needs to move all the work to the lowest
+    * numbered CPUs in the group, therefore mark all groups
+    * higher than ourself as busy.
+    */
+   if ((sd->flags & SD_ASYM_PACKING) && sgs->sum_nr_running &&
+       this_cpu < group_first_cpu(sg)) {
+       if (!sds->busiest)
+           return true;
+
+       if (group_first_cpu(sds->busiest) > group_first_cpu(sg))
+           return true;
+   }
+
+   return false;
+}
+
+/**
+ * update_sd_lb_stats - Update sched_domain's statistics for load balancing.
+ * @sd: sched_domain whose statistics are to be updated.
+ * @this_cpu: Cpu for which load balance is currently performed.
+ * @idle: Idle status of this_cpu
+ * @cpus: Set of cpus considered for load balancing.
+ * @balance: Should we balance.
+ * @sds: variable to hold the statistics for this sched_domain.
+ */
+static inline void update_sd_lb_stats(struct sched_domain *sd, int this_cpu,
+           enum cpu_idle_type idle, const struct cpumask *cpus,
+           int *balance, struct sd_lb_stats *sds)
+{
+   struct sched_domain *child = sd->child;
+   struct sched_group *sg = sd->groups;
+   struct sg_lb_stats sgs;
+   int load_idx, prefer_sibling = 0;
+
+   if (child && child->flags & SD_PREFER_SIBLING)
+       prefer_sibling = 1;
+
+   init_sd_power_savings_stats(sd, sds, idle);
+   load_idx = get_sd_load_idx(sd, idle);
+
+   do {
+       int local_group;
+
+       local_group = cpumask_test_cpu(this_cpu, sched_group_cpus(sg));
+       memset(&sgs, 0, sizeof(sgs));
+       update_sg_lb_stats(sd, sg, this_cpu, idle, load_idx,
+               local_group, cpus, balance, &sgs);
+
+       if (local_group && !(*balance))
+           return;
+
+       sds->total_load += sgs.group_load;
+       sds->total_pwr += sg->sgp->power;
+
+       /*
+        * In case the child domain prefers tasks go to siblings
+        * first, lower the sg capacity to one so that we'll try
+        * and move all the excess tasks away. We lower the capacity
+        * of a group only if the local group has the capacity to fit
+        * these excess tasks, i.e. nr_running < group_capacity. The
+        * extra check prevents the case where you always pull from the
+        * heaviest group when it is already under-utilized (possible
+        * with a large weight task outweighs the tasks on the system).
+        */
+       if (prefer_sibling && !local_group && sds->this_has_capacity)
+           sgs.group_capacity = min(sgs.group_capacity, 1UL);
+
+       if (local_group) {
+           sds->this_load = sgs.avg_load;
+           sds->this = sg;
+           sds->this_nr_running = sgs.sum_nr_running;
+           sds->this_load_per_task = sgs.sum_weighted_load;
+           sds->this_has_capacity = sgs.group_has_capacity;
+           sds->this_idle_cpus = sgs.idle_cpus;
+       } else if (update_sd_pick_busiest(sd, sds, sg, &sgs, this_cpu)) {
+           sds->max_load = sgs.avg_load;
+           sds->busiest = sg;
+           sds->busiest_nr_running = sgs.sum_nr_running;
+           sds->busiest_idle_cpus = sgs.idle_cpus;
+           sds->busiest_group_capacity = sgs.group_capacity;
+           sds->busiest_load_per_task = sgs.sum_weighted_load;
+           sds->busiest_has_capacity = sgs.group_has_capacity;
+           sds->busiest_group_weight = sgs.group_weight;
+           sds->group_imb = sgs.group_imb;
+       }
+
+       update_sd_power_savings_stats(sg, sds, local_group, &sgs);
+       sg = sg->next;
+   } while (sg != sd->groups);
+}
+
+/**
+ * check_asym_packing - Check to see if the group is packed into the
+ *         sched doman.
+ *
+ * This is primarily intended to used at the sibling level.  Some
+ * cores like POWER7 prefer to use lower numbered SMT threads.  In the
+ * case of POWER7, it can move to lower SMT modes only when higher
+ * threads are idle.  When in lower SMT modes, the threads will
+ * perform better since they share less core resources.  Hence when we
+ * have idle threads, we want them to be the higher ones.
+ *
+ * This packing function is run on idle threads.  It checks to see if
+ * the busiest CPU in this domain (core in the P7 case) has a higher
+ * CPU number than the packing function is being run on.  Here we are
+ * assuming lower CPU number will be equivalent to lower a SMT thread
+ * number.
+ *
+ * Returns 1 when packing is required and a task should be moved to
+ * this CPU.  The amount of the imbalance is returned in *imbalance.
+ *
+ * @sd: The sched_domain whose packing is to be checked.
+ * @sds: Statistics of the sched_domain which is to be packed
+ * @this_cpu: The cpu at whose sched_domain we're performing load-balance.
+ * @imbalance: returns amount of imbalanced due to packing.
+ */
+static int check_asym_packing(struct sched_domain *sd,
+                 struct sd_lb_stats *sds,
+                 int this_cpu, unsigned long *imbalance)
+{
+   int busiest_cpu;
+
+   if (!(sd->flags & SD_ASYM_PACKING))
+       return 0;
+
+   if (!sds->busiest)
+       return 0;
+
+   busiest_cpu = group_first_cpu(sds->busiest);
+   if (this_cpu > busiest_cpu)
+       return 0;
+
+   *imbalance = DIV_ROUND_CLOSEST(sds->max_load * sds->busiest->sgp->power,
+                      SCHED_POWER_SCALE);
+   return 1;
+}
+
+/**
+ * fix_small_imbalance - Calculate the minor imbalance that exists
+ *         amongst the groups of a sched_domain, during
+ *         load balancing.
+ * @sds: Statistics of the sched_domain whose imbalance is to be calculated.
+ * @this_cpu: The cpu at whose sched_domain we're performing load-balance.
+ * @imbalance: Variable to store the imbalance.
+ */
+static inline void fix_small_imbalance(struct sd_lb_stats *sds,
+               int this_cpu, unsigned long *imbalance)
+{
+   unsigned long tmp, pwr_now = 0, pwr_move = 0;
+   unsigned int imbn = 2;
+   unsigned long scaled_busy_load_per_task;
+
+   if (sds->this_nr_running) {
+       sds->this_load_per_task /= sds->this_nr_running;
+       if (sds->busiest_load_per_task >
+               sds->this_load_per_task)
+           imbn = 1;
+   } else
+       sds->this_load_per_task =
+           cpu_avg_load_per_task(this_cpu);
+
+   scaled_busy_load_per_task = sds->busiest_load_per_task
+                    * SCHED_POWER_SCALE;
+   scaled_busy_load_per_task /= sds->busiest->sgp->power;
+
+   if (sds->max_load - sds->this_load + scaled_busy_load_per_task >=
+           (scaled_busy_load_per_task * imbn)) {
+       *imbalance = sds->busiest_load_per_task;
+       return;
+   }
+
+   /*
+    * OK, we don't have enough imbalance to justify moving tasks,
+    * however we may be able to increase total CPU power used by
+    * moving them.
+    */
+
+   pwr_now += sds->busiest->sgp->power *
+           min(sds->busiest_load_per_task, sds->max_load);
+   pwr_now += sds->this->sgp->power *
+           min(sds->this_load_per_task, sds->this_load);
+   pwr_now /= SCHED_POWER_SCALE;
+
+   /* Amount of load we'd subtract */
+   tmp = (sds->busiest_load_per_task * SCHED_POWER_SCALE) /
+       sds->busiest->sgp->power;
+   if (sds->max_load > tmp)
+       pwr_move += sds->busiest->sgp->power *
+           min(sds->busiest_load_per_task, sds->max_load - tmp);
+
+   /* Amount of load we'd add */
+   if (sds->max_load * sds->busiest->sgp->power <
+       sds->busiest_load_per_task * SCHED_POWER_SCALE)
+       tmp = (sds->max_load * sds->busiest->sgp->power) /
+           sds->this->sgp->power;
+   else
+       tmp = (sds->busiest_load_per_task * SCHED_POWER_SCALE) /
+           sds->this->sgp->power;
+   pwr_move += sds->this->sgp->power *
+           min(sds->this_load_per_task, sds->this_load + tmp);
+   pwr_move /= SCHED_POWER_SCALE;
+
+   /* Move if we gain throughput */
+   if (pwr_move > pwr_now)
+       *imbalance = sds->busiest_load_per_task;
+}
+
+/**
+ * calculate_imbalance - Calculate the amount of imbalance present within the
+ *          groups of a given sched_domain during load balance.
+ * @sds: statistics of the sched_domain whose imbalance is to be calculated.
+ * @this_cpu: Cpu for which currently load balance is being performed.
+ * @imbalance: The variable to store the imbalance.
+ */
+static inline void calculate_imbalance(struct sd_lb_stats *sds, int this_cpu,
+       unsigned long *imbalance)
+{
+   unsigned long max_pull, load_above_capacity = ~0UL;
+
+   sds->busiest_load_per_task /= sds->busiest_nr_running;
+   if (sds->group_imb) {
+       sds->busiest_load_per_task =
+           min(sds->busiest_load_per_task, sds->avg_load);
+   }
+
+   /*
+    * In the presence of smp nice balancing, certain scenarios can have
+    * max load less than avg load(as we skip the groups at or below
+    * its cpu_power, while calculating max_load..)
+    */
+   if (sds->max_load < sds->avg_load) {
+       *imbalance = 0;
+       return fix_small_imbalance(sds, this_cpu, imbalance);
+   }
+
+   if (!sds->group_imb) {
+       /*
+        * Don't want to pull so many tasks that a group would go idle.
+        */
+       load_above_capacity = (sds->busiest_nr_running -
+                       sds->busiest_group_capacity);
+
+       load_above_capacity *= (SCHED_LOAD_SCALE * SCHED_POWER_SCALE);
+
+       load_above_capacity /= sds->busiest->sgp->power;
+   }
+
+   /*
+    * We're trying to get all the cpus to the average_load, so we don't
+    * want to push ourselves above the average load, nor do we wish to
+    * reduce the max loaded cpu below the average load. At the same time,
+    * we also don't want to reduce the group load below the group capacity
+    * (so that we can implement power-savings policies etc). Thus we look
+    * for the minimum possible imbalance.
+    * Be careful of negative numbers as they'll appear as very large values
+    * with unsigned longs.
+    */
+   max_pull = min(sds->max_load - sds->avg_load, load_above_capacity);
+
+   /* How much load to actually move to equalise the imbalance */
+   *imbalance = min(max_pull * sds->busiest->sgp->power,
+       (sds->avg_load - sds->this_load) * sds->this->sgp->power)
+           / SCHED_POWER_SCALE;
+
+   /*
+    * if *imbalance is less than the average load per runnable task
+    * there is no guarantee that any tasks will be moved so we'll have
+    * a think about bumping its value to force at least one task to be
+    * moved
+    */
+   if (*imbalance < sds->busiest_load_per_task)
+       return fix_small_imbalance(sds, this_cpu, imbalance);
+
+}
+
+/******* find_busiest_group() helpers end here *********************/
+
+/**
+ * find_busiest_group - Returns the busiest group within the sched_domain
+ * if there is an imbalance. If there isn't an imbalance, and
+ * the user has opted for power-savings, it returns a group whose
+ * CPUs can be put to idle by rebalancing those tasks elsewhere, if
+ * such a group exists.
+ *
+ * Also calculates the amount of weighted load which should be moved
+ * to restore balance.
+ *
+ * @sd: The sched_domain whose busiest group is to be returned.
+ * @this_cpu: The cpu for which load balancing is currently being performed.
+ * @imbalance: Variable which stores amount of weighted load which should
+ *     be moved to restore balance/put a group to idle.
+ * @idle: The idle status of this_cpu.
+ * @cpus: The set of CPUs under consideration for load-balancing.
+ * @balance: Pointer to a variable indicating if this_cpu
+ * is the appropriate cpu to perform load balancing at this_level.
+ *
+ * Returns:    - the busiest group if imbalance exists.
+ *     - If no imbalance and user has opted for power-savings balance,
+ *        return the least loaded group whose CPUs can be
+ *        put to idle by rebalancing its tasks onto our group.
+ */
+static struct sched_group *
+find_busiest_group(struct sched_domain *sd, int this_cpu,
+          unsigned long *imbalance, enum cpu_idle_type idle,
+          const struct cpumask *cpus, int *balance)
+{
+   struct sd_lb_stats sds;
+
+   memset(&sds, 0, sizeof(sds));
+
+   /*
+    * Compute the various statistics relavent for load balancing at
+    * this level.
+    */
+   update_sd_lb_stats(sd, this_cpu, idle, cpus, balance, &sds);
+
+   /*
+    * this_cpu is not the appropriate cpu to perform load balancing at
+    * this level.
+    */
+   if (!(*balance))
+       goto ret;
+
+   if ((idle == CPU_IDLE || idle == CPU_NEWLY_IDLE) &&
+       check_asym_packing(sd, &sds, this_cpu, imbalance))
+       return sds.busiest;
+
+   /* There is no busy sibling group to pull tasks from */
+   if (!sds.busiest || sds.busiest_nr_running == 0)
+       goto out_balanced;
+
+   sds.avg_load = (SCHED_POWER_SCALE * sds.total_load) / sds.total_pwr;
+
+   /*
+    * If the busiest group is imbalanced the below checks don't
+    * work because they assumes all things are equal, which typically
+    * isn't true due to cpus_allowed constraints and the like.
+    */
+   if (sds.group_imb)
+       goto force_balance;
+
+   /* SD_BALANCE_NEWIDLE trumps SMP nice when underutilized */
+   if (idle == CPU_NEWLY_IDLE && sds.this_has_capacity &&
+           !sds.busiest_has_capacity)
+       goto force_balance;
+
+   /*
+    * If the local group is more busy than the selected busiest group
+    * don't try and pull any tasks.
+    */
+   if (sds.this_load >= sds.max_load)
+       goto out_balanced;
+
+   /*
+    * Don't pull any tasks if this group is already above the domain
+    * average load.
+    */
+   if (sds.this_load >= sds.avg_load)
+       goto out_balanced;
+
+   if (idle == CPU_IDLE) {
+       /*
+        * This cpu is idle. If the busiest group load doesn't
+        * have more tasks than the number of available cpu's and
+        * there is no imbalance between this and busiest group
+        * wrt to idle cpu's, it is balanced.
+        */
+       if ((sds.this_idle_cpus <= sds.busiest_idle_cpus + 1) &&
+           sds.busiest_nr_running <= sds.busiest_group_weight)
+           goto out_balanced;
+   } else {
+       /*
+        * In the CPU_NEWLY_IDLE, CPU_NOT_IDLE cases, use
+        * imbalance_pct to be conservative.
+        */
+       if (100 * sds.max_load <= sd->imbalance_pct * sds.this_load)
+           goto out_balanced;
+   }
+
+force_balance:
+   /* Looks like there is an imbalance. Compute it */
+   calculate_imbalance(&sds, this_cpu, imbalance);
+   return sds.busiest;
+
+out_balanced:
+   /*
+    * There is no obvious imbalance. But check if we can do some balancing
+    * to save power.
+    */
+   if (check_power_save_busiest_group(&sds, this_cpu, imbalance))
+       return sds.busiest;
+ret:
+   *imbalance = 0;
+   return NULL;
+}
+
+/*
+ * find_busiest_queue - find the busiest runqueue among the cpus in group.
+ */
+static struct rq *
+find_busiest_queue(struct sched_domain *sd, struct sched_group *group,
+          enum cpu_idle_type idle, unsigned long imbalance,
+          const struct cpumask *cpus)
+{
+   struct rq *busiest = NULL, *rq;
+   unsigned long max_load = 0;
+   int i;
+
+   for_each_cpu(i, sched_group_cpus(group)) {
+       unsigned long power = power_of(i);
+       unsigned long capacity = DIV_ROUND_CLOSEST(power,
+                              SCHED_POWER_SCALE);
+       unsigned long wl;
+
+       if (!capacity)
+           capacity = fix_small_capacity(sd, group);
+
+       if (!cpumask_test_cpu(i, cpus))
+           continue;
+
+       rq = cpu_rq(i);
+       wl = weighted_cpuload(i);
+
+       /*
+        * When comparing with imbalance, use weighted_cpuload()
+        * which is not scaled with the cpu power.
+        */
+       if (capacity && rq->nr_running == 1 && wl > imbalance)
+           continue;
+
+       /*
+        * For the load comparisons with the other cpu's, consider
+        * the weighted_cpuload() scaled with the cpu power, so that
+        * the load can be moved away from the cpu that is potentially
+        * running at a lower capacity.
+        */
+       wl = (wl * SCHED_POWER_SCALE) / power;
+
+       if (wl > max_load) {
+           max_load = wl;
+           busiest = rq;
+       }
+   }
+
+   return busiest;
+}
+
+/*
+ * Max backoff if we encounter pinned tasks. Pretty arbitrary value, but
+ * so long as it is large enough.
+ */
+#define MAX_PINNED_INTERVAL    512
+
+/* Working cpumask for load_balance and load_balance_newidle. */
+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)
+{
+   if (idle == CPU_NEWLY_IDLE) {
+
+       /*
+        * ASYM_PACKING needs to force migrate tasks from busy but
+        * higher numbered CPUs in order to pack all tasks in the
+        * lowest numbered CPUs.
+        */
+       if ((sd->flags & SD_ASYM_PACKING) && busiest_cpu > this_cpu)
+           return 1;
+
+       /*
+        * The only task running in a non-idle cpu can be moved to this
+        * cpu in an attempt to completely freeup the other CPU
+        * package.
+        *
+        * The package power saving logic comes from
+        * find_busiest_group(). If there are no imbalance, then
+        * f_b_g() will return NULL. However when sched_mc={1,2} then
+        * f_b_g() will select a group from which a running task may be
+        * pulled to this cpu in order to make the other package idle.
+        * If there is no opportunity to make a package idle and if
+        * there are no imbalance, then f_b_g() will return NULL and no
+        * action will be taken in load_balance_newidle().
+        *
+        * Under normal task pull operation due to imbalance, there
+        * will be more than one task in the source run queue and
+        * move_tasks() will succeed.  ld_moved will be true and this
+        * active balance code will not be triggered.
+        */
+       if (sched_mc_power_savings < POWERSAVINGS_BALANCE_WAKEUP)
+           return 0;
+   }
+
+   return unlikely(sd->nr_balance_failed > sd->cache_nice_tries+2);
+}
+
+static int active_load_balance_cpu_stop(void *data);
+
+/*
+ * Check this_cpu to ensure it is balanced within domain. Attempt to move
+ * tasks if there is an imbalance.
+ */
+static int load_balance(int this_cpu, struct rq *this_rq,
+           struct sched_domain *sd, enum cpu_idle_type idle,
+           int *balance)
+{
+   int ld_moved, lb_flags = 0, active_balance = 0;
+   struct sched_group *group;
+   unsigned long imbalance;
+   struct rq *busiest;
+   unsigned long flags;
+   struct cpumask *cpus = __get_cpu_var(load_balance_tmpmask);
+
+   cpumask_copy(cpus, cpu_active_mask);
+
+   schedstat_inc(sd, lb_count[idle]);
+
+redo:
+   group = find_busiest_group(sd, this_cpu, &imbalance, idle,
+                  cpus, balance);
+
+   if (*balance == 0)
+       goto out_balanced;
+
+   if (!group) {
+       schedstat_inc(sd, lb_nobusyg[idle]);
+       goto out_balanced;
+   }
+
+   busiest = find_busiest_queue(sd, group, idle, imbalance, cpus);
+   if (!busiest) {
+       schedstat_inc(sd, lb_nobusyq[idle]);
+       goto out_balanced;
+   }
+
+   BUG_ON(busiest == this_rq);
+
+   schedstat_add(sd, lb_imbalance[idle], imbalance);
+
+   ld_moved = 0;
+   if (busiest->nr_running > 1) {
+       /*
+        * Attempt to move tasks. If find_busiest_group has found
+        * an imbalance but busiest->nr_running <= 1, the group is
+        * still unbalanced. ld_moved simply stays zero, so it is
+        * correctly treated as an imbalance.
+        */
+       lb_flags |= LBF_ALL_PINNED;
+       local_irq_save(flags);
+       double_rq_lock(this_rq, busiest);
+       ld_moved = move_tasks(this_rq, this_cpu, busiest,
+                     imbalance, sd, idle, &lb_flags);
+       double_rq_unlock(this_rq, busiest);
+       local_irq_restore(flags);
+
+       /*
+        * some other cpu did the load balance for us.
+        */
+       if (ld_moved && this_cpu != smp_processor_id())
+           resched_cpu(this_cpu);
+
+       if (lb_flags & LBF_ABORT)
+           goto out_balanced;
+
+       if (lb_flags & LBF_NEED_BREAK) {
+           lb_flags += LBF_HAD_BREAK - LBF_NEED_BREAK;
+           if (lb_flags & LBF_ABORT)
+               goto out_balanced;
+           goto redo;
+       }
+
+       /* All tasks on this runqueue were pinned by CPU affinity */
+       if (unlikely(lb_flags & LBF_ALL_PINNED)) {
+           cpumask_clear_cpu(cpu_of(busiest), cpus);
+           if (!cpumask_empty(cpus))
+               goto redo;
+           goto out_balanced;
+       }
+   }
+
+   if (!ld_moved) {
+       schedstat_inc(sd, lb_failed[idle]);
+       /*
+        * Increment the failure counter only on periodic balance.
+        * We do not want newidle balance, which can be very
+        * frequent, pollute the failure counter causing
+        * excessive cache_hot migrations and active balances.
+        */
+       if (idle != CPU_NEWLY_IDLE)
+           sd->nr_balance_failed++;
+
+       if (need_active_balance(sd, idle, cpu_of(busiest), this_cpu)) {
+           raw_spin_lock_irqsave(&busiest->lock, flags);
+
+           /* don't kick the active_load_balance_cpu_stop,
+            * if the curr task on busiest cpu can't be
+            * moved to this_cpu
+            */
+           if (!cpumask_test_cpu(this_cpu,
+                   tsk_cpus_allowed(busiest->curr))) {
+               raw_spin_unlock_irqrestore(&busiest->lock,
+                               flags);
+               lb_flags |= LBF_ALL_PINNED;
+               goto out_one_pinned;
+           }
+
+           /*
+            * ->active_balance synchronizes accesses to
+            * ->active_balance_work.  Once set, it's cleared
+            * only after active load balance is finished.
+            */
+           if (!busiest->active_balance) {
+               busiest->active_balance = 1;
+               busiest->push_cpu = this_cpu;
+               active_balance = 1;
+           }
+           raw_spin_unlock_irqrestore(&busiest->lock, flags);
+
+           if (active_balance)
+               stop_one_cpu_nowait(cpu_of(busiest),
+                   active_load_balance_cpu_stop, busiest,
+                   &busiest->active_balance_work);
+
+           /*
+            * We've kicked active balancing, reset the failure
+            * counter.
+            */
+           sd->nr_balance_failed = sd->cache_nice_tries+1;
+       }
+   } else
+       sd->nr_balance_failed = 0;
+
+   if (likely(!active_balance)) {
+       /* We were unbalanced, so reset the balancing interval */
+       sd->balance_interval = sd->min_interval;
+   } else {
+       /*
+        * If we've begun active balancing, start to back off. This
+        * case may not be covered by the all_pinned logic if there
+        * is only 1 task on the busy runqueue (because we don't call
+        * move_tasks).
+        */
+       if (sd->balance_interval < sd->max_interval)
+           sd->balance_interval *= 2;
+   }
+
+   goto out;
+
+out_balanced:
+   schedstat_inc(sd, lb_balanced[idle]);
+
+   sd->nr_balance_failed = 0;
+
+out_one_pinned:
+   /* tune up the balancing interval */
+   if (((lb_flags & LBF_ALL_PINNED) &&
+           sd->balance_interval < MAX_PINNED_INTERVAL) ||
+           (sd->balance_interval < sd->max_interval))
+       sd->balance_interval *= 2;
+
+   ld_moved = 0;
+out:
+   return ld_moved;
+}
+
+/*
+ * idle_balance is called by schedule() if this_cpu is about to become
+ * idle. Attempts to pull tasks from other CPUs.
+ */
+void idle_balance(int this_cpu, struct rq *this_rq)
+{
+   struct sched_domain *sd;
+   int pulled_task = 0;
+   unsigned long next_balance = jiffies + HZ;
+
+   this_rq->idle_stamp = this_rq->clock;
+
+   if (this_rq->avg_idle < sysctl_sched_migration_cost)
+       return;
+
+   /*
+    * Drop the rq->lock, but keep IRQ/preempt disabled.
+    */
+   raw_spin_unlock(&this_rq->lock);
+
+   update_shares(this_cpu);
+   rcu_read_lock();
+   for_each_domain(this_cpu, sd) {
+       unsigned long interval;
+       int balance = 1;
+
+       if (!(sd->flags & SD_LOAD_BALANCE))
+           continue;
+
+       if (sd->flags & SD_BALANCE_NEWIDLE) {
+           /* If we've pulled tasks over stop searching: */
+           pulled_task = load_balance(this_cpu, this_rq,
+                          sd, CPU_NEWLY_IDLE, &balance);
+       }
+
+       interval = msecs_to_jiffies(sd->balance_interval);
+       if (time_after(next_balance, sd->last_balance + interval))
+           next_balance = sd->last_balance + interval;
+       if (pulled_task) {
+           this_rq->idle_stamp = 0;
+           break;
+       }
+   }
+   rcu_read_unlock();
+
+   raw_spin_lock(&this_rq->lock);
+
+   if (pulled_task || time_after(jiffies, this_rq->next_balance)) {
+       /*
+        * We are going idle. next_balance may be set based on
+        * a busy processor. So reset next_balance.
+        */
+       this_rq->next_balance = next_balance;
+   }
+}
+
+/*
+ * active_load_balance_cpu_stop is run by cpu stopper. It pushes
+ * running tasks off the busiest CPU onto idle CPUs. It requires at
+ * least 1 task to be running on each physical CPU where possible, and
+ * avoids physical / logical imbalances.
+ */
+static int active_load_balance_cpu_stop(void *data)
+{
+   struct rq *busiest_rq = data;
+   int busiest_cpu = cpu_of(busiest_rq);
+   int target_cpu = busiest_rq->push_cpu;
+   struct rq *target_rq = cpu_rq(target_cpu);
+   struct sched_domain *sd;
+
+   raw_spin_lock_irq(&busiest_rq->lock);
+
+   /* make sure the requested cpu hasn't gone down in the meantime */
+   if (unlikely(busiest_cpu != smp_processor_id() ||
+            !busiest_rq->active_balance))
+       goto out_unlock;
+
+   /* Is there any task to move? */
+   if (busiest_rq->nr_running <= 1)
+       goto out_unlock;
+
+   /*
+    * This condition is "impossible", if it occurs
+    * we need to fix it. Originally reported by
+    * Bjorn Helgaas on a 128-cpu setup.
+    */
+   BUG_ON(busiest_rq == target_rq);
+
+   /* move a task from busiest_rq to target_rq */
+   double_lock_balance(busiest_rq, target_rq);
+
+   /* Search for an sd spanning us and the target CPU. */
+   rcu_read_lock();
+   for_each_domain(target_cpu, sd) {
+       if ((sd->flags & SD_LOAD_BALANCE) &&
+           cpumask_test_cpu(busiest_cpu, sched_domain_span(sd)))
+               break;
+   }
+
+   if (likely(sd)) {
+       schedstat_inc(sd, alb_count);
+
+       if (move_one_task(target_rq, target_cpu, busiest_rq,
+                 sd, CPU_IDLE))
+           schedstat_inc(sd, alb_pushed);
+       else
+           schedstat_inc(sd, alb_failed);
+   }
+   rcu_read_unlock();
+   double_unlock_balance(busiest_rq, target_rq);
+out_unlock:
+   busiest_rq->active_balance = 0;
+   raw_spin_unlock_irq(&busiest_rq->lock);
+   return 0;
+}
+
+#ifdef CONFIG_NO_HZ
+/*
+ * idle load balancing details
+ * - When one of the busy CPUs notice that there may be an idle rebalancing
+ *   needed, they will kick the idle load balancer, which then does idle
+ *   load balancing for all the idle CPUs.
+ */
+static struct {
+   cpumask_var_t idle_cpus_mask;
+   atomic_t nr_cpus;
+   unsigned long next_balance;     /* in jiffy units */
+} nohz ____cacheline_aligned;
+
+#if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT)
+/**
+ * lowest_flag_domain - Return lowest sched_domain containing flag.
+ * @cpu:   The cpu whose lowest level of sched domain is to
+ *     be returned.
+ * @flag:  The flag to check for the lowest sched_domain
+ *     for the given cpu.
+ *
+ * Returns the lowest sched_domain of a cpu which contains the given flag.
+ */
+static inline struct sched_domain *lowest_flag_domain(int cpu, int flag)
+{
+   struct sched_domain *sd;
+
+   for_each_domain(cpu, sd)
+       if (sd->flags & flag)
+           break;
+
+   return sd;
+}
+
+/**
+ * for_each_flag_domain - Iterates over sched_domains containing the flag.
+ * @cpu:   The cpu whose domains we're iterating over.
+ * @sd:        variable holding the value of the power_savings_sd
+ *     for cpu.
+ * @flag:  The flag to filter the sched_domains to be iterated.
+ *
+ * Iterates over all the scheduler domains for a given cpu that has the 'flag'
+ * set, starting from the lowest sched_domain to the highest.
+ */
+#define for_each_flag_domain(cpu, sd, flag) \
+   for (sd = lowest_flag_domain(cpu, flag); \
+       (sd && (sd->flags & flag)); sd = sd->parent)
+
+/**
+ * find_new_ilb - Finds the optimum idle load balancer for nomination.
+ * @cpu:   The cpu which is nominating a new idle_load_balancer.
+ *
+ * Returns:    Returns the id of the idle load balancer if it exists,
+ *     Else, returns >= nr_cpu_ids.
+ *
+ * This algorithm picks the idle load balancer such that it belongs to a
+ * semi-idle powersavings sched_domain. The idea is to try and avoid
+ * completely idle packages/cores just for the purpose of idle load balancing
+ * when there are other idle cpu's which are better suited for that job.
+ */
+static int find_new_ilb(int cpu)
+{
+   int ilb = cpumask_first(nohz.idle_cpus_mask);
+   struct sched_group *ilbg;
+   struct sched_domain *sd;
+
+   /*
+    * Have idle load balancer selection from semi-idle packages only
+    * when power-aware load balancing is enabled
+    */
+   if (!(sched_smt_power_savings || sched_mc_power_savings))
+       goto out_done;
+
+   /*
+    * Optimize for the case when we have no idle CPUs or only one
+    * idle CPU. Don't walk the sched_domain hierarchy in such cases
+    */
+   if (cpumask_weight(nohz.idle_cpus_mask) < 2)
+       goto out_done;
+
+   rcu_read_lock();
+   for_each_flag_domain(cpu, sd, SD_POWERSAVINGS_BALANCE) {
+       ilbg = sd->groups;
+
+       do {
+           if (ilbg->group_weight !=
+               atomic_read(&ilbg->sgp->nr_busy_cpus)) {
+               ilb = cpumask_first_and(nohz.idle_cpus_mask,
+                           sched_group_cpus(ilbg));
+               goto unlock;
+           }
+
+           ilbg = ilbg->next;
+
+       } while (ilbg != sd->groups);
+   }
+unlock:
+   rcu_read_unlock();
+
+out_done:
+   if (ilb < nr_cpu_ids && idle_cpu(ilb))
+       return ilb;
+
+   return nr_cpu_ids;
+}
+#else /*  (CONFIG_SCHED_MC || CONFIG_SCHED_SMT) */
+static inline int find_new_ilb(int call_cpu)
+{
+   return nr_cpu_ids;
+}
+#endif
+
+/*
+ * Kick a CPU to do the nohz balancing, if it is time for it. We pick the
+ * nohz_load_balancer CPU (if there is one) otherwise fallback to any idle
+ * CPU (if there is one).
+ */
+static void nohz_balancer_kick(int cpu)
+{
+   int ilb_cpu;
+
+   nohz.next_balance++;
+
+   ilb_cpu = find_new_ilb(cpu);
+
+   if (ilb_cpu >= nr_cpu_ids)
+       return;
+
+   if (test_and_set_bit(NOHZ_BALANCE_KICK, nohz_flags(ilb_cpu)))
+       return;
+   /*
+    * Use smp_send_reschedule() instead of resched_cpu().
+    * This way we generate a sched IPI on the target cpu which
+    * is idle. And the softirq performing nohz idle load balance
+    * will be run before returning from the IPI.
+    */
+   smp_send_reschedule(ilb_cpu);
+   return;
+}
+
+static inline void clear_nohz_tick_stopped(int cpu)
+{
+   if (unlikely(test_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu)))) {
+       cpumask_clear_cpu(cpu, nohz.idle_cpus_mask);
+       atomic_dec(&nohz.nr_cpus);
+       clear_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu));
+   }
+}
+
+static inline void set_cpu_sd_state_busy(void)
+{
+   struct sched_domain *sd;
+   int cpu = smp_processor_id();
+
+   if (!test_bit(NOHZ_IDLE, nohz_flags(cpu)))
+       return;
+   clear_bit(NOHZ_IDLE, nohz_flags(cpu));
+
+   rcu_read_lock();
+   for_each_domain(cpu, sd)
+       atomic_inc(&sd->groups->sgp->nr_busy_cpus);
+   rcu_read_unlock();
+}
+
+void set_cpu_sd_state_idle(void)
+{
+   struct sched_domain *sd;
+   int cpu = smp_processor_id();
+
+   if (test_bit(NOHZ_IDLE, nohz_flags(cpu)))
+       return;
+   set_bit(NOHZ_IDLE, nohz_flags(cpu));
+
+   rcu_read_lock();
+   for_each_domain(cpu, sd)
+       atomic_dec(&sd->groups->sgp->nr_busy_cpus);
+   rcu_read_unlock();
+}
+
+/*
+ * This routine will record that this cpu is going idle with tick stopped.
+ * This info will be used in performing idle load balancing in the future.
+ */
+void select_nohz_load_balancer(int stop_tick)
+{
+   int cpu = smp_processor_id();
+
+   /*
+    * If this cpu is going down, then nothing needs to be done.
+    */
+   if (!cpu_active(cpu))
+       return;
+
+   if (stop_tick) {
+       if (test_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu)))
+           return;
+
+       cpumask_set_cpu(cpu, nohz.idle_cpus_mask);
+       atomic_inc(&nohz.nr_cpus);
+       set_bit(NOHZ_TICK_STOPPED, nohz_flags(cpu));
+   }
+   return;
+}
+
+static int __cpuinit sched_ilb_notifier(struct notifier_block *nfb,
+                   unsigned long action, void *hcpu)
+{
+   switch (action & ~CPU_TASKS_FROZEN) {
+   case CPU_DYING:
+       clear_nohz_tick_stopped(smp_processor_id());
+       return NOTIFY_OK;
+   default:
+       return NOTIFY_DONE;
+   }
+}
+#endif
+
+static DEFINE_SPINLOCK(balancing);
+
+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.
+ */
+void update_max_interval(void)
+{
+   max_load_balance_interval = HZ*num_online_cpus()/10;
+}
+
+/*
+ * It checks each scheduling domain to see if it is due to be balanced,
+ * and initiates a balancing operation if so.
+ *
+ * Balancing parameters are set up in arch_init_sched_domains.
+ */
+static void rebalance_domains(int cpu, enum cpu_idle_type idle)
+{
+   int balance = 1;
+   struct rq *rq = cpu_rq(cpu);
+   unsigned long interval;
+   struct sched_domain *sd;
+   /* Earliest time when we have to do rebalance again */
+   unsigned long next_balance = jiffies + 60*HZ;
+   int update_next_balance = 0;
+   int need_serialize;
+
+   update_shares(cpu);
+
+   rcu_read_lock();
+   for_each_domain(cpu, sd) {
+       if (!(sd->flags & SD_LOAD_BALANCE))
+           continue;
+
+       interval = sd->balance_interval;
+       if (idle != CPU_IDLE)
+           interval *= sd->busy_factor;
+
+       /* scale ms to jiffies */
+       interval = msecs_to_jiffies(interval);
+       interval = clamp(interval, 1UL, max_load_balance_interval);
+
+       need_serialize = sd->flags & SD_SERIALIZE;
+
+       if (need_serialize) {
+           if (!spin_trylock(&balancing))
+               goto out;
+       }
+
+       if (time_after_eq(jiffies, sd->last_balance + interval)) {
+           if (load_balance(cpu, rq, sd, idle, &balance)) {
+               /*
+                * We've pulled tasks over so either we're no
+                * longer idle.
+                */
+               idle = CPU_NOT_IDLE;
+           }
+           sd->last_balance = jiffies;
+       }
+       if (need_serialize)
+           spin_unlock(&balancing);
+out:
+       if (time_after(next_balance, sd->last_balance + interval)) {
+           next_balance = sd->last_balance + interval;
+           update_next_balance = 1;
+       }
+
+       /*
+        * Stop the load balance at this level. There is another
+        * CPU in our sched group which is doing load balancing more
+        * actively.
+        */
+       if (!balance)
+           break;
+   }
+   rcu_read_unlock();
+
+   /*
+    * next_balance will be updated only when there is a need.
+    * When the cpu is attached to null domain for ex, it will not be
+    * updated.
+    */
+   if (likely(update_next_balance))
+       rq->next_balance = next_balance;
+}
+
+#ifdef CONFIG_NO_HZ
+/*
+ * In CONFIG_NO_HZ case, the idle balance kickee will do the
+ * rebalancing for all the cpus for whom scheduler ticks are stopped.
+ */
+static void nohz_idle_balance(int this_cpu, enum cpu_idle_type idle)
+{
+   struct rq *this_rq = cpu_rq(this_cpu);
+   struct rq *rq;
+   int balance_cpu;
+
+   if (idle != CPU_IDLE ||
+       !test_bit(NOHZ_BALANCE_KICK, nohz_flags(this_cpu)))
+       goto end;
+
+   for_each_cpu(balance_cpu, nohz.idle_cpus_mask) {
+       if (balance_cpu == this_cpu || !idle_cpu(balance_cpu))
+           continue;
+
+       /*
+        * If this cpu gets work to do, stop the load balancing
+        * work being done for other cpus. Next load
+        * balancing owner will pick it up.
+        */
+       if (need_resched())
+           break;
+
+       raw_spin_lock_irq(&this_rq->lock);
+       update_rq_clock(this_rq);
+       update_cpu_load(this_rq);
+       raw_spin_unlock_irq(&this_rq->lock);
+
+       rebalance_domains(balance_cpu, CPU_IDLE);
+
+       rq = cpu_rq(balance_cpu);
+       if (time_after(this_rq->next_balance, rq->next_balance))
+           this_rq->next_balance = rq->next_balance;
+   }
+   nohz.next_balance = this_rq->next_balance;
+end:
+   clear_bit(NOHZ_BALANCE_KICK, nohz_flags(this_cpu));
+}
+
+/*
+ * Current heuristic for kicking the idle load balancer in the presence
+ * of an idle cpu is the system.
+ *   - This rq has more than one task.
+ *   - At any scheduler domain level, this cpu's scheduler group has multiple
+ *     busy cpu's exceeding the group's power.
+ *   - For SD_ASYM_PACKING, if the lower numbered cpu's in the scheduler
+ *     domain span are idle.
+ */
+static inline int nohz_kick_needed(struct rq *rq, int cpu)
+{
+   unsigned long now = jiffies;
+   struct sched_domain *sd;
+
+   if (unlikely(idle_cpu(cpu)))
+       return 0;
+
+       /*
+   * We may be recently in ticked or tickless idle mode. At the first
+   * busy tick after returning from idle, we will update the busy stats.
+   */
+   set_cpu_sd_state_busy();
+   clear_nohz_tick_stopped(cpu);
+
+   /*
+    * None are in tickless mode and hence no need for NOHZ idle load
+    * balancing.
+    */
+   if (likely(!atomic_read(&nohz.nr_cpus)))
+       return 0;
+
+   if (time_before(now, nohz.next_balance))
+       return 0;
+
+   if (rq->nr_running >= 2)
+       goto need_kick;
+
+   rcu_read_lock();
+   for_each_domain(cpu, sd) {
+       struct sched_group *sg = sd->groups;
+       struct sched_group_power *sgp = sg->sgp;
+       int nr_busy = atomic_read(&sgp->nr_busy_cpus);
+
+       if (sd->flags & SD_SHARE_PKG_RESOURCES && nr_busy > 1)
+           goto need_kick_unlock;
+
+       if (sd->flags & SD_ASYM_PACKING && nr_busy != sg->group_weight
+           && (cpumask_first_and(nohz.idle_cpus_mask,
+                     sched_domain_span(sd)) < cpu))
+           goto need_kick_unlock;
+
+       if (!(sd->flags & (SD_SHARE_PKG_RESOURCES | SD_ASYM_PACKING)))
+           break;
+   }
+   rcu_read_unlock();
+   return 0;
+
+need_kick_unlock:
+   rcu_read_unlock();
+need_kick:
+   return 1;
+}
+#else
+static void nohz_idle_balance(int this_cpu, enum cpu_idle_type idle) { }
+#endif
+
+/*
+ * run_rebalance_domains is triggered when needed from the scheduler tick.
+ * Also triggered for nohz idle balancing (with nohz_balancing_kick set).
+ */
+static void run_rebalance_domains(struct softirq_action *h)
+{
+   int this_cpu = smp_processor_id();
+   struct rq *this_rq = cpu_rq(this_cpu);
+   enum cpu_idle_type idle = this_rq->idle_balance ?
+                       CPU_IDLE : CPU_NOT_IDLE;
+
+   rebalance_domains(this_cpu, idle);
+
+   /*
+    * If this cpu has a pending nohz_balance_kick, then do the
+    * balancing on behalf of the other idle cpus whose ticks are
+    * stopped.
+    */
+   nohz_idle_balance(this_cpu, idle);
+}
+
+static inline int on_null_domain(int cpu)
+{
+   return !rcu_dereference_sched(cpu_rq(cpu)->sd);
+}
+
+/*
+ * Trigger the SCHED_SOFTIRQ if it is time to do periodic load balancing.
+ */
+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) &&
+       likely(!on_null_domain(cpu)))
+       raise_softirq(SCHED_SOFTIRQ);
+#ifdef CONFIG_NO_HZ
+   if (nohz_kick_needed(rq, cpu) && likely(!on_null_domain(cpu)))
+       nohz_balancer_kick(cpu);
+#endif
+}
+
+static void rq_online_fair(struct rq *rq)
+{
+   update_sysctl();
+}
+
+static void rq_offline_fair(struct rq *rq)
+{
+   update_sysctl();
+}
+
+#endif /* CONFIG_SMP */
+
+/*
+ * scheduler tick hitting a task of our scheduling class:
+ */
+static void task_tick_fair(struct rq *rq, struct task_struct *curr, int queued)
+{
+   struct cfs_rq *cfs_rq;
+   struct sched_entity *se = &curr->se;
+
+   for_each_sched_entity(se) {
+       cfs_rq = cfs_rq_of(se);
+       entity_tick(cfs_rq, se, queued);
+   }
+}
+
+/*
+ * called on fork with the child task as argument from the parent's context
+ *  - child not yet on the tasklist
+ *  - preemption disabled
+ */
+static void task_fork_fair(struct task_struct *p)
+{
+   struct cfs_rq *cfs_rq;
+   struct sched_entity *se = &p->se, *curr;
+   int this_cpu = smp_processor_id();
+   struct rq *rq = this_rq();
+   unsigned long flags;
+
+   raw_spin_lock_irqsave(&rq->lock, flags);
+
+   update_rq_clock(rq);
+
+   cfs_rq = task_cfs_rq(current);
+   curr = cfs_rq->curr;
+
+   if (unlikely(task_cpu(p) != this_cpu)) {
+       rcu_read_lock();
+       __set_task_cpu(p, this_cpu);
+       rcu_read_unlock();
+   }
+
+   update_curr(cfs_rq);
+
+   if (curr)
+       se->vruntime = curr->vruntime;
+   place_entity(cfs_rq, se, 1);
+
+   if (sysctl_sched_child_runs_first && curr && entity_before(curr, se)) {
+       /*
+        * Upon rescheduling, sched_class::put_prev_task() will place
+        * 'current' within the tree based on its new key value.
+        */
+       swap(curr->vruntime, se->vruntime);
+       resched_task(rq->curr);
+   }
+
+   se->vruntime -= cfs_rq->min_vruntime;
+
+   raw_spin_unlock_irqrestore(&rq->lock, flags);
+}
+
+/*
+ * Priority of the task has changed. Check to see if we preempt
+ * the current task.
+ */
+static void
+prio_changed_fair(struct rq *rq, struct task_struct *p, int oldprio)
+{
+   if (!p->se.on_rq)
+       return;
+
+   /*
+    * Reschedule if we are currently running on this runqueue and
+    * our priority decreased, or if we are not currently running on
+    * this runqueue and our priority is higher than the current's
+    */
+   if (rq->curr == p) {
+       if (p->prio > oldprio)
+           resched_task(rq->curr);
+   } else
+       check_preempt_curr(rq, p, 0);
+}
+
+static void switched_from_fair(struct rq *rq, struct task_struct *p)
+{
+   struct sched_entity *se = &p->se;
+   struct cfs_rq *cfs_rq = cfs_rq_of(se);
+
+   /*
+    * Ensure the task's vruntime is normalized, so that when its
+    * switched back to the fair class the enqueue_entity(.flags=0) will
+    * do the right thing.
+    *
+    * If it was on_rq, then the dequeue_entity(.flags=0) will already
+    * have normalized the vruntime, if it was !on_rq, then only when
+    * the task is sleeping will it still have non-normalized vruntime.
+    */
+   if (!se->on_rq && p->state != TASK_RUNNING) {
+       /*
+        * Fix up our vruntime so that the current sleep doesn't
+        * cause 'unlimited' sleep bonus.
+        */
+       place_entity(cfs_rq, se, 0);
+       se->vruntime -= cfs_rq->min_vruntime;
+   }
+}
+
+/*
+ * We switched to the sched_fair class.
+ */
+static void switched_to_fair(struct rq *rq, struct task_struct *p)
+{
+   if (!p->se.on_rq)
+       return;
+
+   /*
+    * We were most likely switched from sched_rt, so
+    * kick off the schedule if running, otherwise just see
+    * if we can still preempt the current task.
+    */
+   if (rq->curr == p)
+       resched_task(rq->curr);
+   else
+       check_preempt_curr(rq, p, 0);
+}
+
+/* Account for a task changing its policy or group.
+ *
+ * This routine is mostly called to set cfs_rq->curr field when a task
+ * migrates between groups/classes.
+ */
+static void set_curr_task_fair(struct rq *rq)
+{
+   struct sched_entity *se = &rq->curr->se;
+
+   for_each_sched_entity(se) {
+       struct cfs_rq *cfs_rq = cfs_rq_of(se);
+
+       set_next_entity(cfs_rq, se);
+       /* ensure bandwidth has been allocated on our new cfs_rq */
+       account_cfs_rq_runtime(cfs_rq, 0);
+   }
+}
+
+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)
+{
+   /*
+    * If the task was not on the rq at the time of this cgroup movement
+    * it must have been asleep, sleeping tasks keep their ->vruntime
+    * absolute on their old rq until wakeup (needed for the fair sleeper
+    * bonus in place_entity()).
+    *
+    * If it was on the rq, we've just 'preempted' it, which does convert
+    * ->vruntime to a relative base.
+    *
+    * Make sure both cases convert their relative position when migrating
+    * to another cgroup's rq. This does somewhat interfere with the
+    * fair sleeper stuff for the first placement, but who cares.
+    */
+   /*
+    * When !on_rq, vruntime of the task has usually NOT been normalized.
+    * But there are some cases where it has already been normalized:
+    *
+    * - Moving a forked child which is waiting for being woken up by
+    *   wake_up_new_task().
+    * - Moving a task which has been woken up by try_to_wake_up() and
+    *   waiting for actually being woken up by sched_ttwu_pending().
+    *
+    * To prevent boost or penalty in the new cfs_rq caused by delta
+    * min_vruntime between the two cfs_rqs, we skip vruntime adjustment.
+    */
+   if (!on_rq && (!p->se.sum_exec_runtime || p->state == TASK_WAKING))
+       on_rq = 1;
+
+   if (!on_rq)
+       p->se.vruntime -= cfs_rq_of(&p->se)->min_vruntime;
+   set_task_rq(p, task_cpu(p));
+   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)
+{
+   struct sched_entity *se = &task->se;
+   unsigned int rr_interval = 0;
+
+   /*
+    * Time slice is 0 for SCHED_OTHER tasks that are on an otherwise
+    * idle runqueue:
+    */
+   if (rq->cfs.load.weight)
+       rr_interval = NS_TO_JIFFIES(sched_slice(&rq->cfs, se));
+
+   return rr_interval;
+}
+
+/*
+ * All the scheduling class methods:
+ */
+const struct sched_class fair_sched_class = {
+   .next           = &idle_sched_class,
+   .enqueue_task       = enqueue_task_fair,
+   .dequeue_task       = dequeue_task_fair,
+   .yield_task     = yield_task_fair,
+   .yield_to_task      = yield_to_task_fair,
+
+   .check_preempt_curr = check_preempt_wakeup,
+
+   .pick_next_task     = pick_next_task_fair,
+   .put_prev_task      = put_prev_task_fair,
+
+#ifdef CONFIG_SMP
+   .select_task_rq     = select_task_rq_fair,
+
+   .rq_online      = rq_online_fair,
+   .rq_offline     = rq_offline_fair,
+
+   .task_waking        = task_waking_fair,
+#endif
+
+   .set_curr_task          = set_curr_task_fair,
+   .task_tick      = task_tick_fair,
+   .task_fork      = task_fork_fair,
+
+   .prio_changed       = prio_changed_fair,
+   .switched_from      = switched_from_fair,
+   .switched_to        = switched_to_fair,
+
+   .get_rr_interval    = get_rr_interval_fair,
+
+#ifdef CONFIG_FAIR_GROUP_SCHED
+   .task_move_group    = task_move_group_fair,
+#endif
+};
+
+#ifdef CONFIG_SCHED_DEBUG
+void print_cfs_stats(struct seq_file *m, int cpu)
+{
+   struct cfs_rq *cfs_rq;
+
+   rcu_read_lock();
+   for_each_leaf_cfs_rq(cpu_rq(cpu), cfs_rq)
+       print_cfs_rq(m, cpu, cfs_rq);
+   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);
+   cpu_notifier(sched_ilb_notifier, 0);
+#endif
+#endif /* SMP */
+
+}
diff -Naur linux-3.3.7.orig/kernel/sched/sched.h linux-3.3.7/kernel/sched/sched.h
--- linux-3.3.7.orig/kernel/sched/sched.h   2012-05-21 21:42:51.000000000 +0300
+++ linux-3.3.7/kernel/sched/sched.h    2012-05-23 21:52:34.000000000 +0300
@@ -474,6 +474,17 @@
 #ifdef CONFIG_SMP
    struct llist_head wake_list;
 #endif
+#ifdef CONFIG_BLD
+   unsigned long this_cpu_load;
+   struct list_head disp_load_balance;
+   /* It indicates whether, rq is first or last
+    * or in the middle based on load from rq_head.
+    * 0 - First rq
+    * 1 - rq stays middle
+    * 2 - last rq
+    */
+   char pos;
+#endif
 };

 static inline int cpu_of(struct rq *rq)