Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler updates from Ingo Molnar:
 "The biggest changes in this cycle were:

   - Make kcpustat vtime aware (Frederic Weisbecker)

   - Rework the CFS load_balance() logic (Vincent Guittot)

   - Misc cleanups, smaller enhancements, fixes.

  The load-balancing rework is the most intrusive change: it replaces
  the old heuristics that have become less meaningful after the
  introduction of the PELT metrics, with a grounds-up load-balancing
  algorithm.

  As such it's not really an iterative series, but replaces the old
  load-balancing logic with the new one. We hope there are no
  performance regressions left - but statistically it's highly probable
  that there *is* going to be some workload that is hurting from these
  chnages. If so then we'd prefer to have a look at that workload and
  fix its scheduling, instead of reverting the changes"

* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (46 commits)
  rackmeter: Use vtime aware kcpustat accessor
  leds: Use all-in-one vtime aware kcpustat accessor
  cpufreq: Use vtime aware kcpustat accessors for user time
  procfs: Use all-in-one vtime aware kcpustat accessor
  sched/vtime: Bring up complete kcpustat accessor
  sched/cputime: Support other fields on kcpustat_field()
  sched/cpufreq: Move the cfs_rq_util_change() call to cpufreq_update_util()
  sched/fair: Add comments for group_type and balancing at SD_NUMA level
  sched/fair: Fix rework of find_idlest_group()
  sched/uclamp: Fix overzealous type replacement
  sched/Kconfig: Fix spelling mistake in user-visible help text
  sched/core: Further clarify sched_class::set_next_task()
  sched/fair: Use mul_u32_u32()
  sched/core: Simplify sched_class::pick_next_task()
  sched/core: Optimize pick_next_task()
  sched/core: Make pick_next_task_idle() more consistent
  sched/fair: Better document newidle_balance()
  leds: Use vtime aware kcpustat accessor to fetch CPUTIME_SYSTEM
  cpufreq: Use vtime aware kcpustat accessor to fetch CPUTIME_SYSTEM
  procfs: Use vtime aware kcpustat accessor to fetch CPUTIME_SYSTEM
  ...

13 files changed, 1177 insertions, 644 deletions

diff --git a/kernel/Kconfig.preempt b/kernel/Kconfig.preempt
index deff97217496..bf82259cff96 100644
--- a/kernel/Kconfig.preempt
+++ b/kernel/Kconfig.preempt
@@ -65,7 +65,7 @@ config PREEMPT_RT
 	  preemptible priority-inheritance aware variants, enforcing
 	  interrupt threading and introducing mechanisms to break up long
 	  non-preemptible sections. This makes the kernel, except for very
-	  low level and critical code pathes (entry code, scheduler, low
+	  low level and critical code paths (entry code, scheduler, low
 	  level interrupt handling) fully preemptible and brings most
 	  execution contexts under scheduler control.
 
diff --git a/kernel/context_tracking.c b/kernel/context_tracking.c
index be01a4d627c9..0296b4bda8f1 100644
--- a/kernel/context_tracking.c
+++ b/kernel/context_tracking.c
@@ -25,8 +25,8 @@
 #define CREATE_TRACE_POINTS
 #include <trace/events/context_tracking.h>
 
-DEFINE_STATIC_KEY_FALSE(context_tracking_enabled);
-EXPORT_SYMBOL_GPL(context_tracking_enabled);
+DEFINE_STATIC_KEY_FALSE(context_tracking_key);
+EXPORT_SYMBOL_GPL(context_tracking_key);
 
 DEFINE_PER_CPU(struct context_tracking, context_tracking);
 EXPORT_SYMBOL_GPL(context_tracking);
@@ -192,7 +192,7 @@ void __init context_tracking_cpu_set(int cpu)
 
 	if (!per_cpu(context_tracking.active, cpu)) {
 		per_cpu(context_tracking.active, cpu) = true;
-		static_branch_inc(&context_tracking_enabled);
+		static_branch_inc(&context_tracking_key);
 	}
 
 	if (initialized)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 80b60ca7767f..d82e2f6ac41d 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -811,7 +811,7 @@ static inline unsigned int uclamp_bucket_base_value(unsigned int clamp_value)
 	return UCLAMP_BUCKET_DELTA * uclamp_bucket_id(clamp_value);
 }
 
-static inline enum uclamp_id uclamp_none(enum uclamp_id clamp_id)
+static inline unsigned int uclamp_none(enum uclamp_id clamp_id)
 {
 	if (clamp_id == UCLAMP_MIN)
 		return 0;
@@ -854,7 +854,7 @@ static inline void uclamp_idle_reset(struct rq *rq, enum uclamp_id clamp_id,
 }
 
 static inline
-enum uclamp_id uclamp_rq_max_value(struct rq *rq, enum uclamp_id clamp_id,
+unsigned int uclamp_rq_max_value(struct rq *rq, enum uclamp_id clamp_id,
 				   unsigned int clamp_value)
 {
 	struct uclamp_bucket *bucket = rq->uclamp[clamp_id].bucket;
@@ -919,7 +919,7 @@ uclamp_eff_get(struct task_struct *p, enum uclamp_id clamp_id)
 	return uc_req;
 }
 
-enum uclamp_id uclamp_eff_value(struct task_struct *p, enum uclamp_id clamp_id)
+unsigned int uclamp_eff_value(struct task_struct *p, enum uclamp_id clamp_id)
 {
 	struct uclamp_se uc_eff;
 
@@ -3918,13 +3918,15 @@ pick_next_task(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
 		    prev->sched_class == &fair_sched_class) &&
 		   rq->nr_running == rq->cfs.h_nr_running)) {
 
-		p = fair_sched_class.pick_next_task(rq, prev, rf);
+		p = pick_next_task_fair(rq, prev, rf);
 		if (unlikely(p == RETRY_TASK))
 			goto restart;
 
 		/* Assumes fair_sched_class->next == idle_sched_class */
-		if (unlikely(!p))
-			p = idle_sched_class.pick_next_task(rq, prev, rf);
+		if (!p) {
+			put_prev_task(rq, prev);
+			p = pick_next_task_idle(rq);
+		}
 
 		return p;
 	}
@@ -3948,7 +3950,7 @@ restart:
 	put_prev_task(rq, prev);
 
 	for_each_class(class) {
-		p = class->pick_next_task(rq, NULL, NULL);
+		p = class->pick_next_task(rq);
 		if (p)
 			return p;
 	}
@@ -6217,7 +6219,7 @@ static struct task_struct *__pick_migrate_task(struct rq *rq)
 	struct task_struct *next;
 
 	for_each_class(class) {
-		next = class->pick_next_task(rq, NULL, NULL);
+		next = class->pick_next_task(rq);
 		if (next) {
 			next->sched_class->put_prev_task(rq, next);
 			return next;
diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c
index 46ed4e1383e2..d43318a489f2 100644
--- a/kernel/sched/cputime.c
+++ b/kernel/sched/cputime.c
@@ -405,27 +405,25 @@ static inline void irqtime_account_process_tick(struct task_struct *p, int user_
 /*
  * Use precise platform statistics if available:
  */
-#ifdef CONFIG_VIRT_CPU_ACCOUNTING
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
+
 # ifndef __ARCH_HAS_VTIME_TASK_SWITCH
-void vtime_common_task_switch(struct task_struct *prev)
+void vtime_task_switch(struct task_struct *prev)
 {
 	if (is_idle_task(prev))
 		vtime_account_idle(prev);
 	else
-		vtime_account_system(prev);
+		vtime_account_kernel(prev);
 
 	vtime_flush(prev);
 	arch_vtime_task_switch(prev);
 }
 # endif
-#endif /* CONFIG_VIRT_CPU_ACCOUNTING */
 
-
-#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
 /*
  * Archs that account the whole time spent in the idle task
  * (outside irq) as idle time can rely on this and just implement
- * vtime_account_system() and vtime_account_idle(). Archs that
+ * vtime_account_kernel() and vtime_account_idle(). Archs that
  * have other meaning of the idle time (s390 only includes the
  * time spent by the CPU when it's in low power mode) must override
  * vtime_account().
@@ -436,7 +434,7 @@ void vtime_account_irq_enter(struct task_struct *tsk)
 	if (!in_interrupt() && is_idle_task(tsk))
 		vtime_account_idle(tsk);
 	else
-		vtime_account_system(tsk);
+		vtime_account_kernel(tsk);
 }
 EXPORT_SYMBOL_GPL(vtime_account_irq_enter);
 #endif /* __ARCH_HAS_VTIME_ACCOUNT */
@@ -477,7 +475,7 @@ void account_process_tick(struct task_struct *p, int user_tick)
 	u64 cputime, steal;
 	struct rq *rq = this_rq();
 
-	if (vtime_accounting_cpu_enabled())
+	if (vtime_accounting_enabled_this_cpu())
 		return;
 
 	if (sched_clock_irqtime) {
@@ -711,8 +709,8 @@ static u64 get_vtime_delta(struct vtime *vtime)
 	return delta - other;
 }
 
-static void __vtime_account_system(struct task_struct *tsk,
-				   struct vtime *vtime)
+static void vtime_account_system(struct task_struct *tsk,
+				 struct vtime *vtime)
 {
 	vtime->stime += get_vtime_delta(vtime);
 	if (vtime->stime >= TICK_NSEC) {
@@ -731,7 +729,17 @@ static void vtime_account_guest(struct task_struct *tsk,
 	}
 }
 
-void vtime_account_system(struct task_struct *tsk)
+static void __vtime_account_kernel(struct task_struct *tsk,
+				   struct vtime *vtime)
+{
+	/* We might have scheduled out from guest path */
+	if (vtime->state == VTIME_GUEST)
+		vtime_account_guest(tsk, vtime);
+	else
+		vtime_account_system(tsk, vtime);
+}
+
+void vtime_account_kernel(struct task_struct *tsk)
 {
 	struct vtime *vtime = &tsk->vtime;
 
@@ -739,11 +747,7 @@ void vtime_account_system(struct task_struct *tsk)
 		return;
 
 	write_seqcount_begin(&vtime->seqcount);
-	/* We might have scheduled out from guest path */
-	if (tsk->flags & PF_VCPU)
-		vtime_account_guest(tsk, vtime);
-	else
-		__vtime_account_system(tsk, vtime);
+	__vtime_account_kernel(tsk, vtime);
 	write_seqcount_end(&vtime->seqcount);
 }
 
@@ -752,7 +756,7 @@ void vtime_user_enter(struct task_struct *tsk)
 	struct vtime *vtime = &tsk->vtime;
 
 	write_seqcount_begin(&vtime->seqcount);
-	__vtime_account_system(tsk, vtime);
+	vtime_account_system(tsk, vtime);
 	vtime->state = VTIME_USER;
 	write_seqcount_end(&vtime->seqcount);
 }
@@ -782,8 +786,9 @@ void vtime_guest_enter(struct task_struct *tsk)
 	 * that can thus safely catch up with a tickless delta.
 	 */
 	write_seqcount_begin(&vtime->seqcount);
-	__vtime_account_system(tsk, vtime);
+	vtime_account_system(tsk, vtime);
 	tsk->flags |= PF_VCPU;
+	vtime->state = VTIME_GUEST;
 	write_seqcount_end(&vtime->seqcount);
 }
 EXPORT_SYMBOL_GPL(vtime_guest_enter);
@@ -795,6 +800,7 @@ void vtime_guest_exit(struct task_struct *tsk)
 	write_seqcount_begin(&vtime->seqcount);
 	vtime_account_guest(tsk, vtime);
 	tsk->flags &= ~PF_VCPU;
+	vtime->state = VTIME_SYS;
 	write_seqcount_end(&vtime->seqcount);
 }
 EXPORT_SYMBOL_GPL(vtime_guest_exit);
@@ -804,19 +810,30 @@ void vtime_account_idle(struct task_struct *tsk)
 	account_idle_time(get_vtime_delta(&tsk->vtime));
 }
 
-void arch_vtime_task_switch(struct task_struct *prev)
+void vtime_task_switch_generic(struct task_struct *prev)
 {
 	struct vtime *vtime = &prev->vtime;
 
 	write_seqcount_begin(&vtime->seqcount);
+	if (vtime->state == VTIME_IDLE)
+		vtime_account_idle(prev);
+	else
+		__vtime_account_kernel(prev, vtime);
 	vtime->state = VTIME_INACTIVE;
+	vtime->cpu = -1;
 	write_seqcount_end(&vtime->seqcount);
 
 	vtime = &current->vtime;
 
 	write_seqcount_begin(&vtime->seqcount);
-	vtime->state = VTIME_SYS;
+	if (is_idle_task(current))
+		vtime->state = VTIME_IDLE;
+	else if (current->flags & PF_VCPU)
+		vtime->state = VTIME_GUEST;
+	else
+		vtime->state = VTIME_SYS;
 	vtime->starttime = sched_clock();
+	vtime->cpu = smp_processor_id();
 	write_seqcount_end(&vtime->seqcount);
 }
 
@@ -827,8 +844,9 @@ void vtime_init_idle(struct task_struct *t, int cpu)
 
 	local_irq_save(flags);
 	write_seqcount_begin(&vtime->seqcount);
-	vtime->state = VTIME_SYS;
+	vtime->state = VTIME_IDLE;
 	vtime->starttime = sched_clock();
+	vtime->cpu = cpu;
 	write_seqcount_end(&vtime->seqcount);
 	local_irq_restore(flags);
 }
@@ -846,7 +864,7 @@ u64 task_gtime(struct task_struct *t)
 		seq = read_seqcount_begin(&vtime->seqcount);
 
 		gtime = t->gtime;
-		if (vtime->state == VTIME_SYS && t->flags & PF_VCPU)
+		if (vtime->state == VTIME_GUEST)
 			gtime += vtime->gtime + vtime_delta(vtime);
 
 	} while (read_seqcount_retry(&vtime->seqcount, seq));
@@ -877,20 +895,230 @@ void task_cputime(struct task_struct *t, u64 *utime, u64 *stime)
 		*utime = t->utime;
 		*stime = t->stime;
 
-		/* Task is sleeping, nothing to add */
-		if (vtime->state == VTIME_INACTIVE || is_idle_task(t))
+		/* Task is sleeping or idle, nothing to add */
+		if (vtime->state < VTIME_SYS)
 			continue;
 
 		delta = vtime_delta(vtime);
 
 		/*
-		 * Task runs either in user or kernel space, add pending nohz time to
-		 * the right place.
+		 * Task runs either in user (including guest) or kernel space,
+		 * add pending nohz time to the right place.
 		 */
-		if (vtime->state == VTIME_USER || t->flags & PF_VCPU)
-			*utime += vtime->utime + delta;
-		else if (vtime->state == VTIME_SYS)
+		if (vtime->state == VTIME_SYS)
 			*stime += vtime->stime + delta;
+		else
+			*utime += vtime->utime + delta;
+	} while (read_seqcount_retry(&vtime->seqcount, seq));
+}
+
+static int vtime_state_check(struct vtime *vtime, int cpu)
+{
+	/*
+	 * We raced against a context switch, fetch the
+	 * kcpustat task again.
+	 */
+	if (vtime->cpu != cpu && vtime->cpu != -1)
+		return -EAGAIN;
+
+	/*
+	 * Two possible things here:
+	 * 1) We are seeing the scheduling out task (prev) or any past one.
+	 * 2) We are seeing the scheduling in task (next) but it hasn't
+	 *    passed though vtime_task_switch() yet so the pending
+	 *    cputime of the prev task may not be flushed yet.
+	 *
+	 * Case 1) is ok but 2) is not. So wait for a safe VTIME state.
+	 */
+	if (vtime->state == VTIME_INACTIVE)
+		return -EAGAIN;
+
+	return 0;
+}
+
+static u64 kcpustat_user_vtime(struct vtime *vtime)
+{
+	if (vtime->state == VTIME_USER)
+		return vtime->utime + vtime_delta(vtime);
+	else if (vtime->state == VTIME_GUEST)
+		return vtime->gtime + vtime_delta(vtime);
+	return 0;
+}
+
+static int kcpustat_field_vtime(u64 *cpustat,
+				struct task_struct *tsk,
+				enum cpu_usage_stat usage,
+				int cpu, u64 *val)
+{
+	struct vtime *vtime = &tsk->vtime;
+	unsigned int seq;
+	int err;
+
+	do {
+		seq = read_seqcount_begin(&vtime->seqcount);
+
+		err = vtime_state_check(vtime, cpu);
+		if (err < 0)
+			return err;
+
+		*val = cpustat[usage];
+
+		/*
+		 * Nice VS unnice cputime accounting may be inaccurate if
+		 * the nice value has changed since the last vtime update.
+		 * But proper fix would involve interrupting target on nice
+		 * updates which is a no go on nohz_full (although the scheduler
+		 * may still interrupt the target if rescheduling is needed...)
+		 */
+		switch (usage) {
+		case CPUTIME_SYSTEM:
+			if (vtime->state == VTIME_SYS)
+				*val += vtime->stime + vtime_delta(vtime);
+			break;
+		case CPUTIME_USER:
+			if (task_nice(tsk) <= 0)
+				*val += kcpustat_user_vtime(vtime);
+			break;
+		case CPUTIME_NICE:
+			if (task_nice(tsk) > 0)
+				*val += kcpustat_user_vtime(vtime);
+			break;
+		case CPUTIME_GUEST:
+			if (vtime->state == VTIME_GUEST && task_nice(tsk) <= 0)
+				*val += vtime->gtime + vtime_delta(vtime);
+			break;
+		case CPUTIME_GUEST_NICE:
+			if (vtime->state == VTIME_GUEST && task_nice(tsk) > 0)
+				*val += vtime->gtime + vtime_delta(vtime);
+			break;
+		default:
+			break;
+		}
+	} while (read_seqcount_retry(&vtime->seqcount, seq));
+
+	return 0;
+}
+
+u64 kcpustat_field(struct kernel_cpustat *kcpustat,
+		   enum cpu_usage_stat usage, int cpu)
+{
+	u64 *cpustat = kcpustat->cpustat;
+	struct rq *rq;
+	u64 val;
+	int err;
+
+	if (!vtime_accounting_enabled_cpu(cpu))
+		return cpustat[usage];
+
+	rq = cpu_rq(cpu);
+
+	for (;;) {
+		struct task_struct *curr;
+
+		rcu_read_lock();
+		curr = rcu_dereference(rq->curr);
+		if (WARN_ON_ONCE(!curr)) {
+			rcu_read_unlock();
+			return cpustat[usage];
+		}
+
+		err = kcpustat_field_vtime(cpustat, curr, usage, cpu, &val);
+		rcu_read_unlock();
+
+		if (!err)
+			return val;
+
+		cpu_relax();
+	}
+}
+EXPORT_SYMBOL_GPL(kcpustat_field);
+
+static int kcpustat_cpu_fetch_vtime(struct kernel_cpustat *dst,
+				    const struct kernel_cpustat *src,
+				    struct task_struct *tsk, int cpu)
+{
+	struct vtime *vtime = &tsk->vtime;
+	unsigned int seq;
+	int err;
+
+	do {
+		u64 *cpustat;
+		u64 delta;
+
+		seq = read_seqcount_begin(&vtime->seqcount);
+
+		err = vtime_state_check(vtime, cpu);
+		if (err < 0)
+			return err;
+
+		*dst = *src;
+		cpustat = dst->cpustat;
+
+		/* Task is sleeping, dead or idle, nothing to add */
+		if (vtime->state < VTIME_SYS)
+			continue;
+
+		delta = vtime_delta(vtime);
+
+		/*
+		 * Task runs either in user (including guest) or kernel space,
+		 * add pending nohz time to the right place.
+		 */
+		if (vtime->state == VTIME_SYS) {
+			cpustat[CPUTIME_SYSTEM] += vtime->stime + delta;
+		} else if (vtime->state == VTIME_USER) {
+			if (task_nice(tsk) > 0)
+				cpustat[CPUTIME_NICE] += vtime->utime + delta;
+			else
+				cpustat[CPUTIME_USER] += vtime->utime + delta;
+		} else {
+			WARN_ON_ONCE(vtime->state != VTIME_GUEST);
+			if (task_nice(tsk) > 0) {
+				cpustat[CPUTIME_GUEST_NICE] += vtime->gtime + delta;
+				cpustat[CPUTIME_NICE] += vtime->gtime + delta;
+			} else {
+				cpustat[CPUTIME_GUEST] += vtime->gtime + delta;
+				cpustat[CPUTIME_USER] += vtime->gtime + delta;
+			}
+		}
 	} while (read_seqcount_retry(&vtime->seqcount, seq));
+
+	return err;
+}
+
+void kcpustat_cpu_fetch(struct kernel_cpustat *dst, int cpu)
+{
+	const struct kernel_cpustat *src = &kcpustat_cpu(cpu);
+	struct rq *rq;
+	int err;
+
+	if (!vtime_accounting_enabled_cpu(cpu)) {
+		*dst = *src;
+		return;
+	}
+
+	rq = cpu_rq(cpu);
+
+	for (;;) {
+		struct task_struct *curr;
+
+		rcu_read_lock();
+		curr = rcu_dereference(rq->curr);
+		if (WARN_ON_ONCE(!curr)) {
+			rcu_read_unlock();
+			*dst = *src;
+			return;
+		}
+
+		err = kcpustat_cpu_fetch_vtime(dst, src, curr, cpu);
+		rcu_read_unlock();
+
+		if (!err)
+			return;
+
+		cpu_relax();
+	}
 }
+EXPORT_SYMBOL_GPL(kcpustat_cpu_fetch);
+
 #endif /* CONFIG_VIRT_CPU_ACCOUNTING_GEN */
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index a8a08030a8f7..43323f875cb9 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -1743,13 +1743,16 @@ static void start_hrtick_dl(struct rq *rq, struct task_struct *p)
 }
 #endif
 
-static void set_next_task_dl(struct rq *rq, struct task_struct *p)
+static void set_next_task_dl(struct rq *rq, struct task_struct *p, bool first)
 {
 	p->se.exec_start = rq_clock_task(rq);
 
 	/* You can't push away the running task */
 	dequeue_pushable_dl_task(rq, p);
 
+	if (!first)
+		return;
+
 	if (hrtick_enabled(rq))
 		start_hrtick_dl(rq, p);
 
@@ -1770,22 +1773,19 @@ static struct sched_dl_entity *pick_next_dl_entity(struct rq *rq,
 	return rb_entry(left, struct sched_dl_entity, rb_node);
 }
 
-static struct task_struct *
-pick_next_task_dl(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
+static struct task_struct *pick_next_task_dl(struct rq *rq)
 {
 	struct sched_dl_entity *dl_se;
 	struct dl_rq *dl_rq = &rq->dl;
 	struct task_struct *p;
 
-	WARN_ON_ONCE(prev || rf);
-
 	if (!sched_dl_runnable(rq))
 		return NULL;
 
 	dl_se = pick_next_dl_entity(rq, dl_rq);
 	BUG_ON(!dl_se);
 	p = dl_task_of(dl_se);
-	set_next_task_dl(rq, p);
+	set_next_task_dl(rq, p, true);
 	return p;
 }
 
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 69a81a5709ff..08a233e97a01 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -229,8 +229,7 @@ static u64 __calc_delta(u64 delta_exec, unsigned long weight, struct load_weight
 		}
 	}
 
-	/* hint to use a 32x32->64 mul */
-	fact = (u64)(u32)fact * lw->inv_weight;
+	fact = mul_u32_u32(fact, lw->inv_weight);
 
 	while (fact >> 32) {
 		fact >>= 1;
@@ -1474,7 +1473,12 @@ bool should_numa_migrate_memory(struct task_struct *p, struct page * page,
 	       group_faults_cpu(ng, src_nid) * group_faults(p, dst_nid) * 4;
 }
 
-static unsigned long cpu_runnable_load(struct rq *rq);
+static inline unsigned long cfs_rq_runnable_load_avg(struct cfs_rq *cfs_rq);
+
+static unsigned long cpu_runnable_load(struct rq *rq)
+{
+	return cfs_rq_runnable_load_avg(&rq->cfs);
+}
 
 /* Cached statistics for all CPUs within a node */
 struct numa_stats {
@@ -3504,9 +3508,6 @@ update_cfs_rq_load_avg(u64 now, struct cfs_rq *cfs_rq)
 	cfs_rq->load_last_update_time_copy = sa->last_update_time;
 #endif
 
-	if (decayed)
-		cfs_rq_util_change(cfs_rq, 0);
-
 	return decayed;
 }
 
@@ -3616,8 +3617,12 @@ static inline void update_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *s
 		attach_entity_load_avg(cfs_rq, se, SCHED_CPUFREQ_MIGRATION);
 		update_tg_load_avg(cfs_rq, 0);
 
-	} else if (decayed && (flags & UPDATE_TG))
-		update_tg_load_avg(cfs_rq, 0);
+	} else if (decayed) {
+		cfs_rq_util_change(cfs_rq, 0);
+
+		if (flags & UPDATE_TG)
+			update_tg_load_avg(cfs_rq, 0);
+	}
 }
 
 #ifndef CONFIG_64BIT
@@ -3764,10 +3769,21 @@ util_est_dequeue(struct cfs_rq *cfs_rq, struct task_struct *p, bool task_sleep)
 		return;
 
 	/*
+	 * Reset EWMA on utilization increases, the moving average is used only
+	 * to smooth utilization decreases.
+	 */
+	ue.enqueued = (task_util(p) | UTIL_AVG_UNCHANGED);
+	if (sched_feat(UTIL_EST_FASTUP)) {
+		if (ue.ewma < ue.enqueued) {
+			ue.ewma = ue.enqueued;
+			goto done;
+		}
+	}
+
+	/*
 	 * Skip update of task's estimated utilization when its EWMA is
 	 * already ~1% close to its last activation value.
 	 */
-	ue.enqueued = (task_util(p) | UTIL_AVG_UNCHANGED);
 	last_ewma_diff = ue.enqueued - ue.ewma;
 	if (within_margin(last_ewma_diff, (SCHED_CAPACITY_SCALE / 100)))
 		return;
@@ -3800,6 +3816,7 @@ util_est_dequeue(struct cfs_rq *cfs_rq, struct task_struct *p, bool task_sleep)
 	ue.ewma <<= UTIL_EST_WEIGHT_SHIFT;
 	ue.ewma  += last_ewma_diff;
 	ue.ewma >>= UTIL_EST_WEIGHT_SHIFT;
+done:
 	WRITE_ONCE(p->se.avg.util_est, ue);
 }
 
@@ -5370,26 +5387,45 @@ static int sched_idle_cpu(int cpu)
 			rq->nr_running);
 }
 
-static unsigned long cpu_runnable_load(struct rq *rq)
+static unsigned long cpu_load(struct rq *rq)
 {
-	return cfs_rq_runnable_load_avg(&rq->cfs);
+	return cfs_rq_load_avg(&rq->cfs);
 }
 
-static unsigned long capacity_of(int cpu)
+/*
+ * cpu_load_without - compute CPU load without any contributions from *p
+ * @cpu: the CPU which load is requested
+ * @p: the task which load should be discounted
+ *
+ * The load of a CPU is defined by the load of tasks currently enqueued on that
+ * CPU as well as tasks which are currently sleeping after an execution on that
+ * CPU.
+ *
+ * This method returns the load of the specified CPU by discounting the load of
+ * the specified task, whenever the task is currently contributing to the CPU
+ * load.
+ */
+static unsigned long cpu_load_without(struct rq *rq, struct task_struct *p)
 {
-	return cpu_rq(cpu)->cpu_capacity;
-}
+	struct cfs_rq *cfs_rq;
+	unsigned int load;
 
-static unsigned long cpu_avg_load_per_task(int cpu)
-{
-	struct rq *rq = cpu_rq(cpu);
-	unsigned long nr_running = READ_ONCE(rq->cfs.h_nr_running);
-	unsigned long load_avg = cpu_runnable_load(rq);
+	/* Task has no contribution or is new */
+	if (cpu_of(rq) != task_cpu(p) || !READ_ONCE(p->se.avg.last_update_time))
+		return cpu_load(rq);
 
-	if (nr_running)
-		return load_avg / nr_running;
+	cfs_rq = &rq->cfs;
+	load = READ_ONCE(cfs_rq->avg.load_avg);
 
-	return 0;
+	/* Discount task's util from CPU's util */
+	lsub_positive(&load, task_h_load(p));
+
+	return load;
+}
+
+static unsigned long capacity_of(int cpu)
+{
+	return cpu_rq(cpu)->cpu_capacity;
 }
 
 static void record_wakee(struct task_struct *p)
@@ -5482,7 +5518,7 @@ wake_affine_weight(struct sched_domain *sd, struct task_struct *p,
 	s64 this_eff_load, prev_eff_load;
 	unsigned long task_load;
 
-	this_eff_load = cpu_runnable_load(cpu_rq(this_cpu));
+	this_eff_load = cpu_load(cpu_rq(this_cpu));
 
 	if (sync) {
 		unsigned long current_load = task_h_load(current);
@@ -5500,7 +5536,7 @@ wake_affine_weight(struct sched_domain *sd, struct task_struct *p,
 		this_eff_load *= 100;
 	this_eff_load *= capacity_of(prev_cpu);
 
-	prev_eff_load = cpu_runnable_load(cpu_rq(prev_cpu));
+	prev_eff_load = cpu_load(cpu_rq(prev_cpu));
 	prev_eff_load -= task_load;
 	if (sched_feat(WA_BIAS))
 		prev_eff_load *= 100 + (sd->imbalance_pct - 100) / 2;
@@ -5538,149 +5574,9 @@ static int wake_affine(struct sched_domain *sd, struct task_struct *p,
 	return target;
 }
 
-static unsigned long cpu_util_without(int cpu, struct task_struct *p);
-
-static unsigned long capacity_spare_without(int cpu, struct task_struct *p)
-{
-	return max_t(long, capacity_of(cpu) - cpu_util_without(cpu, p), 0);
-}
-
-/*
- * find_idlest_group finds and returns the least busy CPU group within the
- * domain.
- *
- * Assumes p is allowed on at least one CPU in sd.
- */
 static struct sched_group *
 find_idlest_group(struct sched_domain *sd, struct task_struct *p,
-		  int this_cpu, int sd_flag)
-{
-	struct sched_group *idlest = NULL, *group = sd->groups;
-	struct sched_group *most_spare_sg = NULL;
-	unsigned long min_runnable_load = ULONG_MAX;
-	unsigned long this_runnable_load = ULONG_MAX;
-	unsigned long min_avg_load = ULONG_MAX, this_avg_load = ULONG_MAX;
-	unsigned long most_spare = 0, this_spare = 0;
-	int imbalance_scale = 100 + (sd->imbalance_pct-100)/2;
-	unsigned long imbalance = scale_load_down(NICE_0_LOAD) *
-				(sd->imbalance_pct-100) / 100;
-
-	do {
-		unsigned long load, avg_load, runnable_load;
-		unsigned long spare_cap, max_spare_cap;
-		int local_group;
-		int i;
-
-		/* Skip over this group if it has no CPUs allowed */
-		if (!cpumask_intersects(sched_group_span(group),
-					p->cpus_ptr))
-			continue;
-
-		local_group = cpumask_test_cpu(this_cpu,
-					       sched_group_span(group));
-
-		/*
-		 * Tally up the load of all CPUs in the group and find
-		 * the group containing the CPU with most spare capacity.
-		 */
-		avg_load = 0;
-		runnable_load = 0;
-		max_spare_cap = 0;
-
-		for_each_cpu(i, sched_group_span(group)) {
-			load = cpu_runnable_load(cpu_rq(i));
-			runnable_load += load;
-
-			avg_load += cfs_rq_load_avg(&cpu_rq(i)->cfs);
-
-			spare_cap = capacity_spare_without(i, p);
-
-			if (spare_cap > max_spare_cap)
-				max_spare_cap = spare_cap;
-		}
-
-		/* Adjust by relative CPU capacity of the group */
-		avg_load = (avg_load * SCHED_CAPACITY_SCALE) /
-					group->sgc->capacity;
-		runnable_load = (runnable_load * SCHED_CAPACITY_SCALE) /
-					group->sgc->capacity;
-
-		if (local_group) {
-			this_runnable_load = runnable_load;
-			this_avg_load = avg_load;
-			this_spare = max_spare_cap;
-		} else {
-			if (min_runnable_load > (runnable_load + imbalance)) {
-				/*
-				 * The runnable load is significantly smaller
-				 * so we can pick this new CPU:
-				 */
-				min_runnable_load = runnable_load;
-				min_avg_load = avg_load;
-				idlest = group;
-			} else if ((runnable_load < (min_runnable_load + imbalance)) &&
-				   (100*min_avg_load > imbalance_scale*avg_load)) {
-				/*
-				 * The runnable loads are close so take the
-				 * blocked load into account through avg_load:
-				 */
-				min_avg_load = avg_load;
-				idlest = group;
-			}
-
-			if (most_spare < max_spare_cap) {
-				most_spare = max_spare_cap;
-				most_spare_sg = group;
-			}
-		}
-	} while (group = group->next, group != sd->groups);
-
-	/*
-	 * The cross-over point between using spare capacity or least load
-	 * is too conservative for high utilization tasks on partially
-	 * utilized systems if we require spare_capacity > task_util(p),
-	 * so we allow for some task stuffing by using
-	 * spare_capacity > task_util(p)/2.
-	 *
-	 * Spare capacity can't be used for fork because the utilization has
-	 * not been set yet, we must first select a rq to compute the initial
-	 * utilization.
-	 */
-	if (sd_flag & SD_BALANCE_FORK)
-		goto skip_spare;
-
-	if (this_spare > task_util(p) / 2 &&
-	    imbalance_scale*this_spare > 100*most_spare)
-		return NULL;
-
-	if (most_spare > task_util(p) / 2)
-		return most_spare_sg;
-
-skip_spare:
-	if (!idlest)
-		return NULL;
-
-	/*
-	 * When comparing groups across NUMA domains, it's possible for the
-	 * local domain to be very lightly loaded relative to the remote
-	 * domains but "imbalance" skews the comparison making remote CPUs
-	 * look much more favourable. When considering cross-domain, add
-	 * imbalance to the runnable load on the remote node and consider
-	 * staying local.
-	 */
-	if ((sd->flags & SD_NUMA) &&
-	    min_runnable_load + imbalance >= this_runnable_load)
-		return NULL;
-
-	if (min_runnable_load > (this_runnable_load + imbalance))
-		return NULL;
-
-	if ((this_runnable_load < (min_runnable_load + imbalance)) &&
-	     (100*this_avg_load < imbalance_scale*min_avg_load))
-		return NULL;
-
-	return idlest;
-}
+		  int this_cpu, int sd_flag);
 
 /*
  * find_idlest_group_cpu - find the idlest CPU among the CPUs in the group.
@@ -5729,7 +5625,7 @@ find_idlest_group_cpu(struct sched_group *group, struct task_struct *p, int this
 				continue;
 			}
 
-			load = cpu_runnable_load(cpu_rq(i));
+			load = cpu_load(cpu_rq(i));
 			if (load < min_load) {
 				min_load = load;
 				least_loaded_cpu = i;
@@ -5753,7 +5649,7 @@ static inline int find_idlest_cpu(struct sched_domain *sd, struct task_struct *p
 		return prev_cpu;
 
 	/*
-	 * We need task's util for capacity_spare_without, sync it up to
+	 * We need task's util for cpu_util_without, sync it up to
 	 * prev_cpu's last_update_time.
 	 */
 	if (!(sd_flag & SD_BALANCE_FORK))
@@ -6746,7 +6642,7 @@ preempt:
 		set_last_buddy(se);
 }
 
-static struct task_struct *
+struct task_struct *
 pick_next_task_fair(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
 {
 	struct cfs_rq *cfs_rq = &rq->cfs;
@@ -6890,6 +6786,11 @@ idle:
 	return NULL;
 }
 
+static struct task_struct *__pick_next_task_fair(struct rq *rq)
+{
+	return pick_next_task_fair(rq, NULL, NULL);
+}
+
 /*
  * Account for a descheduled task:
  */
@@ -7079,11 +6980,49 @@ static unsigned long __read_mostly max_load_balance_interval = HZ/10;
 
 enum fbq_type { regular, remote, all };
 
+/*
+ * 'group_type' describes the group of CPUs at the moment of load balancing.
+ *
+ * The enum is ordered by pulling priority, with the group with lowest priority
+ * first so the group_type can simply be compared when selecting the busiest
+ * group. See update_sd_pick_busiest().
+ */
 enum group_type {
-	group_other = 0,
+	/* The group has spare capacity that can be used to run more tasks.  */
+	group_has_spare = 0,
+	/*
+	 * The group is fully used and the tasks don't compete for more CPU
+	 * cycles. Nevertheless, some tasks might wait before running.
+	 */
+	group_fully_busy,
+	/*
+	 * SD_ASYM_CPUCAPACITY only: One task doesn't fit with CPU's capacity
+	 * and must be migrated to a more powerful CPU.
+	 */
 	group_misfit_task,
+	/*
+	 * SD_ASYM_PACKING only: One local CPU with higher capacity is available,
+	 * and the task should be migrated to it instead of running on the
+	 * current CPU.
+	 */
+	group_asym_packing,
+	/*
+	 * The tasks' affinity constraints previously prevented the scheduler
+	 * from balancing the load across the system.
+	 */
 	group_imbalanced,
-	group_overloaded,
+	/*
+	 * The CPU is overloaded and can't provide expected CPU cycles to all
+	 * tasks.
+	 */
+	group_overloaded
+};
+
+enum migration_type {
+	migrate_load = 0,
+	migrate_util,
+	migrate_task,
+	migrate_misfit
 };
 
 #define LBF_ALL_PINNED	0x01
@@ -7116,7 +7055,7 @@ struct lb_env {
 	unsigned int		loop_max;
 
 	enum fbq_type		fbq_type;
-	enum group_type		src_grp_type;
+	enum migration_type	migration_type;
 	struct list_head	tasks;
 };
 
@@ -7339,7 +7278,7 @@ static struct task_struct *detach_one_task(struct lb_env *env)
 static const unsigned int sched_nr_migrate_break = 32;
 
 /*
- * detach_tasks() -- tries to detach up to imbalance runnable load from
+ * detach_tasks() -- tries to detach up to imbalance load/util/tasks from
  * busiest_rq, as part of a balancing operation within domain "sd".
  *
  * Returns number of detached tasks if successful and 0 otherwise.
@@ -7347,8 +7286,8 @@ static const unsigned int sched_nr_migrate_break = 32;
 static int detach_tasks(struct lb_env *env)
 {
 	struct list_head *tasks = &env->src_rq->cfs_tasks;
+	unsigned long util, load;
 	struct task_struct *p;
-	unsigned long load;
 	int detached = 0;
 
 	lockdep_assert_held(&env->src_rq->lock);
@@ -7381,19 +7320,46 @@ static int detach_tasks(struct lb_env *env)
 		if (!can_migrate_task(p, env))
 			goto next;
 
-		load = task_h_load(p);
+		switch (env->migration_type) {
+		case migrate_load:
+			load = task_h_load(p);
 
-		if (sched_feat(LB_MIN) && load < 16 && !env->sd->nr_balance_failed)
-			goto next;
+			if (sched_feat(LB_MIN) &&
+			    load < 16 && !env->sd->nr_balance_failed)
+				goto next;
 
-		if ((load / 2) > env->imbalance)
-			goto next;
+			if (load/2 > env->imbalance)
+				goto next;
+
+			env->imbalance -= load;
+			break;
+
+		case migrate_util:
+			util = task_util_est(p);
+
+			if (util > env->imbalance)
+				goto next;
+
+			env->imbalance -= util;
+			break;
+
+		case migrate_task:
+			env->imbalance--;
+			break;
+
+		case migrate_misfit:
+			/* This is not a misfit task */
+			if (task_fits_capacity(p, capacity_of(env->src_cpu)))
+				goto next;
+
+			env->imbalance = 0;
+			break;
+		}
 
 		detach_task(p, env);
 		list_add(&p->se.group_node, &env->tasks);
 
 		detached++;
-		env->imbalance -= load;
 
 #ifdef CONFIG_PREEMPTION
 		/*
@@ -7407,7 +7373,7 @@ static int detach_tasks(struct lb_env *env)
 
 		/*
 		 * We only want to steal up to the prescribed amount of
-		 * runnable load.
+		 * load/util/tasks.
 		 */
 		if (env->imbalance <= 0)
 			break;
@@ -7517,6 +7483,28 @@ static inline bool others_have_blocked(struct rq *rq) { return false; }
 static inline void update_blocked_load_status(struct rq *rq, bool has_blocked) {}
 #endif
 
+static bool __update_blocked_others(struct rq *rq, bool *done)
+{
+	const struct sched_class *curr_class;
+	u64 now = rq_clock_pelt(rq);
+	bool decayed;
+
+	/*
+	 * update_load_avg() can call cpufreq_update_util(). Make sure that RT,
+	 * DL and IRQ signals have been updated before updating CFS.
+	 */
+	curr_class = rq->curr->sched_class;
+
+	decayed = update_rt_rq_load_avg(now, rq, curr_class == &rt_sched_class) |
+		  update_dl_rq_load_avg(now, rq, curr_class == &dl_sched_class) |
+		  update_irq_load_avg(rq, 0);
+
+	if (others_have_blocked(rq))
+		*done = false;
+
+	return decayed;
+}
+
 #ifdef CONFIG_FAIR_GROUP_SCHED
 
 static inline bool cfs_rq_is_decayed(struct cfs_rq *cfs_rq)
@@ -7536,29 +7524,11 @@ static inline bool cfs_rq_is_decayed(struct cfs_rq *cfs_rq)
 	return true;
 }
 
-static void update_blocked_averages(int cpu)
+static bool __update_blocked_fair(struct rq *rq, bool *done)
 {
-	struct rq *rq = cpu_rq(cpu);
 	struct cfs_rq *cfs_rq, *pos;
-	const struct sched_class *curr_class;
-	struct rq_flags rf;
-	bool done = true;
-
-	rq_lock_irqsave(rq, &rf);
-	update_rq_clock(rq);
-
-	/*
-	 * update_cfs_rq_load_avg() can call cpufreq_update_util(). Make sure
-	 * that RT, DL and IRQ signals have been updated before updating CFS.
-	 */
-	curr_class = rq->curr->sched_class;
-	update_rt_rq_load_avg(rq_clock_pelt(rq), rq, curr_class == &rt_sched_class);
-	update_dl_rq_load_avg(rq_clock_pelt(rq), rq, curr_class == &dl_sched_class);
-	update_irq_load_avg(rq, 0);
-
-	/* Don't need periodic decay once load/util_avg are null */
-	if (others_have_blocked(rq))
-		done = false;
+	bool decayed = false;
+	int cpu = cpu_of(rq);
 
 	/*
 	 * Iterates the task_group tree in a bottom up fashion, see
@@ -7567,9 +7537,13 @@ static void update_blocked_averages(int cpu)
 	for_each_leaf_cfs_rq_safe(rq, cfs_rq, pos) {
 		struct sched_entity *se;
 
-		if (update_cfs_rq_load_avg(cfs_rq_clock_pelt(cfs_rq), cfs_rq))
+		if (update_cfs_rq_load_avg(cfs_rq_clock_pelt(cfs_rq), cfs_rq)) {
 			update_tg_load_avg(cfs_rq, 0);
 
+			if (cfs_rq == &rq->cfs)
+				decayed = true;
+		}
+
 		/* Propagate pending load changes to the parent, if any: */
 		se = cfs_rq->tg->se[cpu];
 		if (se && !skip_blocked_update(se))
@@ -7584,11 +7558,10 @@ static void update_blocked_averages(int cpu)
 
 		/* Don't need periodic decay once load/util_avg are null */
 		if (cfs_rq_has_blocked(cfs_rq))
-			done = false;
+			*done = false;
 	}
 
-	update_blocked_load_status(rq, !done);
-	rq_unlock_irqrestore(rq, &rf);
+	return decayed;
 }
 
 /*
@@ -7638,29 +7611,16 @@ static unsigned long task_h_load(struct task_struct *p)
 			cfs_rq_load_avg(cfs_rq) + 1);
 }
 #else
-static inline void update_blocked_averages(int cpu)
+static bool __update_blocked_fair(struct rq *rq, bool *done)
 {
-	struct rq *rq = cpu_rq(cpu);
 	struct cfs_rq *cfs_rq = &rq->cfs;
-	const struct sched_class *curr_class;
-	struct rq_flags rf;
-
-	rq_lock_irqsave(rq, &rf);
-	update_rq_clock(rq);
-
-	/*
-	 * update_cfs_rq_load_avg() can call cpufreq_update_util(). Make sure
-	 * that RT, DL and IRQ signals have been updated before updating CFS.
-	 */
-	curr_class = rq->curr->sched_class;
-	update_rt_rq_load_avg(rq_clock_pelt(rq), rq, curr_class == &rt_sched_class);
-	update_dl_rq_load_avg(rq_clock_pelt(rq), rq, curr_class == &dl_sched_class);
-	update_irq_load_avg(rq, 0);
+	bool decayed;
 
-	update_cfs_rq_load_avg(cfs_rq_clock_pelt(cfs_rq), cfs_rq);
+	decayed = update_cfs_rq_load_avg(cfs_rq_clock_pelt(cfs_rq), cfs_rq);
+	if (cfs_rq_has_blocked(cfs_rq))
+		*done = false;
 
-	update_blocked_load_status(rq, cfs_rq_has_blocked(cfs_rq) || others_have_blocked(rq));
-	rq_unlock_irqrestore(rq, &rf);
+	return decayed;
 }
 
 static unsigned long task_h_load(struct task_struct *p)
@@ -7669,6 +7629,24 @@ static unsigned long task_h_load(struct task_struct *p)
 }
 #endif
 
+static void update_blocked_averages(int cpu)
+{
+	bool decayed = false, done = true;
+	struct rq *rq = cpu_rq(cpu);
+	struct rq_flags rf;
+
+	rq_lock_irqsave(rq, &rf);
+	update_rq_clock(rq);
+
+	decayed |= __update_blocked_others(rq, &done);
+	decayed |= __update_blocked_fair(rq, &done);
+
+	update_blocked_load_status(rq, !done);
+	if (decayed)
+		cpufreq_update_util(rq, 0);
+	rq_unlock_irqrestore(rq, &rf);
+}
+
 /********** Helpers for find_busiest_group ************************/
 
 /*
@@ -7677,14 +7655,14 @@ static unsigned long task_h_load(struct task_struct *p)
 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 load_per_task;
 	unsigned long group_capacity;
 	unsigned long group_util; /* Total utilization of the group */
-	unsigned int sum_nr_running; /* Nr tasks running in the group */
+	unsigned int sum_nr_running; /* Nr of tasks running in the group */
+	unsigned int sum_h_nr_running; /* Nr of CFS tasks running in the group */
 	unsigned int idle_cpus;
 	unsigned int group_weight;
 	enum group_type group_type;
-	int group_no_capacity;
+	unsigned int group_asym_packing; /* Tasks should be moved to preferred CPU */
 	unsigned long group_misfit_task_load; /* A CPU has a task too big for its capacity */
 #ifdef CONFIG_NUMA_BALANCING
 	unsigned int nr_numa_running;
@@ -7699,10 +7677,10 @@ struct sg_lb_stats {
 struct sd_lb_stats {
 	struct sched_group *busiest;	/* Busiest group in this sd */
 	struct sched_group *local;	/* Local group in this sd */
-	unsigned long total_running;
 	unsigned long total_load;	/* Total load of all groups in sd */
 	unsigned long total_capacity;	/* Total capacity of all groups in sd */
 	unsigned long avg_load;	/* Average load across all groups in sd */
+	unsigned int prefer_sibling; /* tasks should go to sibling first */
 
 	struct sg_lb_stats busiest_stat;/* Statistics of the busiest group */
 	struct sg_lb_stats local_stat;	/* Statistics of the local group */
@@ -7713,19 +7691,18 @@ static inline void init_sd_lb_stats(struct sd_lb_stats *sds)
 	/*
 	 * Skimp on the clearing to avoid duplicate work. We can avoid clearing
 	 * local_stat because update_sg_lb_stats() does a full clear/assignment.
-	 * We must however clear busiest_stat::avg_load because
-	 * update_sd_pick_busiest() reads this before assignment.
+	 * We must however set busiest_stat::group_type and
+	 * busiest_stat::idle_cpus to the worst busiest group because
+	 * update_sd_pick_busiest() reads these before assignment.
 	 */
 	*sds = (struct sd_lb_stats){
 		.busiest = NULL,
 		.local = NULL,
-		.total_running = 0UL,
 		.total_load = 0UL,
 		.total_capacity = 0UL,
 		.busiest_stat = {
-			.avg_load = 0UL,
-			.sum_nr_running = 0,
-			.group_type = group_other,
+			.idle_cpus = UINT_MAX,
+			.group_type = group_has_spare,
 		},
 	};
 }
@@ -7913,13 +7890,13 @@ static inline int sg_imbalanced(struct sched_group *group)
  * any benefit for the load balance.
  */
 static inline bool
-group_has_capacity(struct lb_env *env, struct sg_lb_stats *sgs)
+group_has_capacity(unsigned int imbalance_pct, struct sg_lb_stats *sgs)
 {
 	if (sgs->sum_nr_running < sgs->group_weight)
 		return true;
 
 	if ((sgs->group_capacity * 100) >
-			(sgs->group_util * env->sd->imbalance_pct))
+			(sgs->group_util * imbalance_pct))
 		return true;
 
 	return false;
@@ -7934,13 +7911,13 @@ group_has_capacity(struct lb_env *env, struct sg_lb_stats *sgs)
  *  false.
  */
 static inline bool
-group_is_overloaded(struct lb_env *env, struct sg_lb_stats *sgs)
+group_is_overloaded(unsigned int imbalance_pct, struct sg_lb_stats *sgs)
 {
 	if (sgs->sum_nr_running <= sgs->group_weight)
 		return false;
 
 	if ((sgs->group_capacity * 100) <
-			(sgs->group_util * env->sd->imbalance_pct))
+			(sgs->group_util * imbalance_pct))
 		return true;
 
 	return false;
@@ -7967,19 +7944,26 @@ group_smaller_max_cpu_capacity(struct sched_group *sg, struct sched_group *ref)
 }
 
 static inline enum
-group_type group_classify(struct sched_group *group,
+group_type group_classify(unsigned int imbalance_pct,
+			  struct sched_group *group,
 			  struct sg_lb_stats *sgs)
 {
-	if (sgs->group_no_capacity)
+	if (group_is_overloaded(imbalance_pct, sgs))
 		return group_overloaded;
 
 	if (sg_imbalanced(group))
 		return group_imbalanced;
 
+	if (sgs->group_asym_packing)
+		return group_asym_packing;
+
 	if (sgs->group_misfit_task_load)
 		return group_misfit_task;
 
-	return group_other;
+	if (!group_has_capacity(imbalance_pct, sgs))
+		return group_fully_busy;
+
+	return group_has_spare;
 }
 
 static bool update_nohz_stats(struct rq *rq, bool force)
@@ -8016,21 +8000,25 @@ static inline void update_sg_lb_stats(struct lb_env *env,
 				      struct sg_lb_stats *sgs,
 				      int *sg_status)
 {
-	int i, nr_running;
+	int i, nr_running, local_group;
 
 	memset(sgs, 0, sizeof(*sgs));
 
+	local_group = cpumask_test_cpu(env->dst_cpu, sched_group_span(group));
+
 	for_each_cpu_and(i, sched_group_span(group), env->cpus) {
 		struct rq *rq = cpu_rq(i);
 
 		if ((env->flags & LBF_NOHZ_STATS) && update_nohz_stats(rq, false))
 			env->flags |= LBF_NOHZ_AGAIN;
 
-		sgs->group_load += cpu_runnable_load(rq);
+		sgs->group_load += cpu_load(rq);
 		sgs->group_util += cpu_util(i);
-		sgs->sum_nr_running += rq->cfs.h_nr_running;
+		sgs->sum_h_nr_running += rq->cfs.h_nr_running;
 
 		nr_running = rq->nr_running;
+		sgs->sum_nr_running += nr_running;
+
 		if (nr_running > 1)
 			*sg_status |= SG_OVERLOAD;
 
@@ -8044,9 +8032,16 @@ static inline void update_sg_lb_stats(struct lb_env *env,
 		/*
 		 * No need to call idle_cpu() if nr_running is not 0
 		 */
-		if (!nr_running && idle_cpu(i))
+		if (!nr_running && idle_cpu(i)) {
 			sgs->idle_cpus++;
+			/* Idle cpu can't have misfit task */
+			continue;
+		}
 
+		if (local_group)
+			continue;
+
+		/* Check for a misfit task on the cpu */
 		if (env->sd->flags & SD_ASYM_CPUCAPACITY &&
 		    sgs->group_misfit_task_load < rq->misfit_task_load) {
 			sgs->group_misfit_task_load = rq->misfit_task_load;
@@ -8054,17 +8049,24 @@ static inline void update_sg_lb_stats(struct lb_env *env,
 		}
 	}
 
-	/* Adjust by relative CPU capacity of the group */
-	sgs->group_capacity = group->sgc->capacity;
-	sgs->avg_load = (sgs->group_load*SCHED_CAPACITY_SCALE) / sgs->group_capacity;
+	/* Check if dst CPU is idle and preferred to this group */
+	if (env->sd->flags & SD_ASYM_PACKING &&
+	    env->idle != CPU_NOT_IDLE &&
+	    sgs->sum_h_nr_running &&
+	    sched_asym_prefer(env->dst_cpu, group->asym_prefer_cpu)) {
+		sgs->group_asym_packing = 1;
+	}
 
-	if (sgs->sum_nr_running)
-		sgs->load_per_task = sgs->group_load / sgs->sum_nr_running;
+	sgs->group_capacity = group->sgc->capacity;
 
 	sgs->group_weight = group->group_weight;
 
-	sgs->group_no_capacity = group_is_overloaded(env, sgs);
-	sgs->group_type = group_classify(group, sgs);
+	sgs->group_type = group_classify(env->sd->imbalance_pct, group, sgs);
+
+	/* Computing avg_load makes sense only when group is overloaded */
+	if (sgs->group_type == group_overloaded)
+		sgs->avg_load = (sgs->group_load * SCHED_CAPACITY_SCALE) /
+				sgs->group_capacity;
 }
 
 /**
@@ -8087,6 +8089,10 @@ static bool update_sd_pick_busiest(struct lb_env *env,
 {
 	struct sg_lb_stats *busiest = &sds->busiest_stat;
 
+	/* Make sure that there is at least one task to pull */
+	if (!sgs->sum_h_nr_running)
+		return false;
+
 	/*
 	 * Don't try to pull misfit tasks we can't help.
 	 * We can use max_capacity here as reduction in capacity on some
@@ -8095,7 +8101,7 @@ static bool update_sd_pick_busiest(struct lb_env *env,
 	 */
 	if (sgs->group_type == group_misfit_task &&
 	    (!group_smaller_max_cpu_capacity(sg, sds->local) ||
-	     !group_has_capacity(env, &sds->local_stat)))
+	     sds->local_stat.group_type != group_has_spare))
 		return false;
 
 	if (sgs->group_type > busiest->group_type)
@@ -8104,62 +8110,88 @@ static bool update_sd_pick_busiest(struct lb_env *env,
 	if (sgs->group_type < busiest->group_type)
 		return false;
 
-	if (sgs->avg_load <= busiest->avg_load)
-		return false;
-
-	if (!(env->sd->flags & SD_ASYM_CPUCAPACITY))
-		goto asym_packing;
-
 	/*
-	 * Candidate sg has no more than one task per CPU and
-	 * has higher per-CPU capacity. Migrating tasks to less
-	 * capable CPUs may harm throughput. Maximize throughput,
-	 * power/energy consequences are not considered.
+	 * The candidate and the current busiest group are the same type of
+	 * group. Let check which one is the busiest according to the type.
 	 */
-	if (sgs->sum_nr_running <= sgs->group_weight &&
-	    group_smaller_min_cpu_capacity(sds->local, sg))
-		return false;
 
-	/*
-	 * If we have more than one misfit sg go with the biggest misfit.
-	 */
-	if (sgs->group_type == group_misfit_task &&
-	    sgs->group_misfit_task_load < busiest->group_misfit_task_load)
+	switch (sgs->group_type) {
+	case group_overloaded:
+		/* Select the overloaded group with highest avg_load. */
+		if (sgs->avg_load <= busiest->avg_load)
+			return false;
+		break;
+
+	case group_imbalanced:
+		/*
+		 * Select the 1st imbalanced group as we don't have any way to
+		 * choose one more than another.
+		 */
 		return false;
 
-asym_packing:
-	/* This is the busiest node in its class. */
-	if (!(env->sd->flags & SD_ASYM_PACKING))
-		return true;
+	case group_asym_packing:
+		/* Prefer to move from lowest priority CPU's work */
+		if (sched_asym_prefer(sg->asym_prefer_cpu, sds->busiest->asym_prefer_cpu))
+			return false;
+		break;
 
-	/* No ASYM_PACKING if target CPU is already busy */
-	if (env->idle == CPU_NOT_IDLE)
-		return true;
-	/*
-	 * ASYM_PACKING needs to move all the work to the highest
-	 * prority CPUs in the group, therefore mark all groups
-	 * of lower priority than ourself as busy.
-	 */
-	if (sgs->sum_nr_running &&
-	    sched_asym_prefer(env->dst_cpu, sg->asym_prefer_cpu)) {
-		if (!sds->busiest)
-			return true;
+	case group_misfit_task:
+		/*
+		 * If we have more than one misfit sg go with the biggest
+		 * misfit.
+		 */
+		if (sgs->group_misfit_task_load < busiest->group_misfit_task_load)
+			return false;
+		break;
 
-		/* Prefer to move from lowest priority CPU's work */
-		if (sched_asym_prefer(sds->busiest->asym_prefer_cpu,
-				      sg->asym_prefer_cpu))
-			return true;
+	case group_fully_busy:
+		/*
+		 * Select the fully busy group with highest avg_load. In
+		 * theory, there is no need to pull task from such kind of
+		 * group because tasks have all compute capacity that they need
+		 * but we can still improve the overall throughput by reducing
+		 * contention when accessing shared HW resources.
+		 *
+		 * XXX for now avg_load is not computed and always 0 so we
+		 * select the 1st one.
+		 */
+		if (sgs->avg_load <= busiest->avg_load)
+			return false;
+		break;
+
+	case group_has_spare:
+		/*
+		 * Select not overloaded group with lowest number of
+		 * idle cpus. We could also compare the spare capacity
+		 * which is more stable but it can end up that the
+		 * group has less spare capacity but finally more idle
+		 * CPUs which means less opportunity to pull tasks.
+		 */
+		if (sgs->idle_cpus >= busiest->idle_cpus)
+			return false;
+		break;
 	}
 
-	return false;
+	/*
+	 * Candidate sg has no more than one task per CPU and has higher
+	 * per-CPU capacity. Migrating tasks to less capable CPUs may harm
+	 * throughput. Maximize throughput, power/energy consequences are not
+	 * considered.
+	 */
+	if ((env->sd->flags & SD_ASYM_CPUCAPACITY) &&
+	    (sgs->group_type <= group_fully_busy) &&
+	    (group_smaller_min_cpu_capacity(sds->local, sg)))
+		return false;
+
+	return true;
 }
 
 #ifdef CONFIG_NUMA_BALANCING
 static inline enum fbq_type fbq_classify_group(struct sg_lb_stats *sgs)
 {
-	if (sgs->sum_nr_running > sgs->nr_numa_running)
+	if (sgs->sum_h_nr_running > sgs->nr_numa_running)
 		return regular;
-	if (sgs->sum_nr_running > sgs->nr_preferred_running)
+	if (sgs->sum_h_nr_running > sgs->nr_preferred_running)
 		return remote;
 	return all;
 }
@@ -8184,18 +8216,310 @@ static inline enum fbq_type fbq_classify_rq(struct rq *rq)
 }
 #endif /* CONFIG_NUMA_BALANCING */
 
+
+struct sg_lb_stats;
+
+/*
+ * task_running_on_cpu - return 1 if @p is running on @cpu.
+ */
+
+static unsigned int task_running_on_cpu(int cpu, struct task_struct *p)
+{
+	/* Task has no contribution or is new */
+	if (cpu != task_cpu(p) || !READ_ONCE(p->se.avg.last_update_time))
+		return 0;
+
+	if (task_on_rq_queued(p))
+		return 1;
+
+	return 0;
+}
+
+/**
+ * idle_cpu_without - would a given CPU be idle without p ?
+ * @cpu: the processor on which idleness is tested.
+ * @p: task which should be ignored.
+ *
+ * Return: 1 if the CPU would be idle. 0 otherwise.
+ */
+static int idle_cpu_without(int cpu, struct task_struct *p)
+{
+	struct rq *rq = cpu_rq(cpu);
+
+	if (rq->curr != rq->idle && rq->curr != p)
+		return 0;
+
+	/*
+	 * rq->nr_running can't be used but an updated version without the
+	 * impact of p on cpu must be used instead. The updated nr_running
+	 * be computed and tested before calling idle_cpu_without().
+	 */
+
+#ifdef CONFIG_SMP
+	if (!llist_empty(&rq->wake_list))
+		return 0;
+#endif
+
+	return 1;
+}
+
+/*
+ * update_sg_wakeup_stats - Update sched_group's statistics for wakeup.
+ * @sd: The sched_domain level to look for idlest group.
+ * @group: sched_group whose statistics are to be updated.
+ * @sgs: variable to hold the statistics for this group.
+ * @p: The task for which we look for the idlest group/CPU.
+ */
+static inline void update_sg_wakeup_stats(struct sched_domain *sd,
+					  struct sched_group *group,
+					  struct sg_lb_stats *sgs,
+					  struct task_struct *p)
+{
+	int i, nr_running;
+
+	memset(sgs, 0, sizeof(*sgs));
+
+	for_each_cpu(i, sched_group_span(group)) {
+		struct rq *rq = cpu_rq(i);
+		unsigned int local;
+
+		sgs->group_load += cpu_load_without(rq, p);
+		sgs->group_util += cpu_util_without(i, p);
+		local = task_running_on_cpu(i, p);
+		sgs->sum_h_nr_running += rq->cfs.h_nr_running - local;
+
+		nr_running = rq->nr_running - local;
+		sgs->sum_nr_running += nr_running;
+
+		/*
+		 * No need to call idle_cpu_without() if nr_running is not 0
+		 */
+		if (!nr_running && idle_cpu_without(i, p))
+			sgs->idle_cpus++;
+
+	}
+
+	/* Check if task fits in the group */
+	if (sd->flags & SD_ASYM_CPUCAPACITY &&
+	    !task_fits_capacity(p, group->sgc->max_capacity)) {
+		sgs->group_misfit_task_load = 1;
+	}
+
+	sgs->group_capacity = group->sgc->capacity;
+
+	sgs->group_type = group_classify(sd->imbalance_pct, group, sgs);
+
+	/*
+	 * Computing avg_load makes sense only when group is fully busy or
+	 * overloaded
+	 */
+	if (sgs->group_type < group_fully_busy)
+		sgs->avg_load = (sgs->group_load * SCHED_CAPACITY_SCALE) /
+				sgs->group_capacity;
+}
+
+static bool update_pick_idlest(struct sched_group *idlest,
+			       struct sg_lb_stats *idlest_sgs,
+			       struct sched_group *group,
+			       struct sg_lb_stats *sgs)
+{
+	if (sgs->group_type < idlest_sgs->group_type)
+		return true;
+
+	if (sgs->group_type > idlest_sgs->group_type)
+		return false;
+
+	/*
+	 * The candidate and the current idlest group are the same type of
+	 * group. Let check which one is the idlest according to the type.
+	 */
+
+	switch (sgs->group_type) {
+	case group_overloaded:
+	case group_fully_busy:
+		/* Select the group with lowest avg_load. */
+		if (idlest_sgs->avg_load <= sgs->avg_load)
+			return false;
+		break;
+
+	case group_imbalanced:
+	case group_asym_packing:
+		/* Those types are not used in the slow wakeup path */
+		return false;
+
+	case group_misfit_task:
+		/* Select group with the highest max capacity */
+		if (idlest->sgc->max_capacity >= group->sgc->max_capacity)
+			return false;
+		break;
+
+	case group_has_spare:
+		/* Select group with most idle CPUs */
+		if (idlest_sgs->idle_cpus >= sgs->idle_cpus)
+			return false;
+		break;
+	}
+
+	return true;
+}
+
+/*
+ * find_idlest_group() finds and returns the least busy CPU group within the
+ * domain.
+ *
+ * Assumes p is allowed on at least one CPU in sd.
+ */
+static struct sched_group *
+find_idlest_group(struct sched_domain *sd, struct task_struct *p,
+		  int this_cpu, int sd_flag)
+{
+	struct sched_group *idlest = NULL, *local = NULL, *group = sd->groups;
+	struct sg_lb_stats local_sgs, tmp_sgs;
+	struct sg_lb_stats *sgs;
+	unsigned long imbalance;
+	struct sg_lb_stats idlest_sgs = {
+			.avg_load = UINT_MAX,
+			.group_type = group_overloaded,
+	};
+
+	imbalance = scale_load_down(NICE_0_LOAD) *
+				(sd->imbalance_pct-100) / 100;
+
+	do {
+		int local_group;
+
+		/* Skip over this group if it has no CPUs allowed */
+		if (!cpumask_intersects(sched_group_span(group),
+					p->cpus_ptr))
+			continue;
+
+		local_group = cpumask_test_cpu(this_cpu,
+					       sched_group_span(group));
+
+		if (local_group) {
+			sgs = &local_sgs;
+			local = group;
+		} else {
+			sgs = &tmp_sgs;
+		}
+
+		update_sg_wakeup_stats(sd, group, sgs, p);
+
+		if (!local_group && update_pick_idlest(idlest, &idlest_sgs, group, sgs)) {
+			idlest = group;
+			idlest_sgs = *sgs;
+		}
+
+	} while (group = group->next, group != sd->groups);
+
+
+	/* There is no idlest group to push tasks to */
+	if (!idlest)
+		return NULL;
+
+	/*
+	 * If the local group is idler than the selected idlest group
+	 * don't try and push the task.
+	 */
+	if (local_sgs.group_type < idlest_sgs.group_type)
+		return NULL;
+
+	/*
+	 * If the local group is busier than the selected idlest group
+	 * try and push the task.
+	 */
+	if (local_sgs.group_type > idlest_sgs.group_type)
+		return idlest;
+
+	switch (local_sgs.group_type) {
+	case group_overloaded:
+	case group_fully_busy:
+		/*
+		 * When comparing groups across NUMA domains, it's possible for
+		 * the local domain to be very lightly loaded relative to the
+		 * remote domains but "imbalance" skews the comparison making
+		 * remote CPUs look much more favourable. When considering
+		 * cross-domain, add imbalance to the load on the remote node
+		 * and consider staying local.
+		 */
+
+		if ((sd->flags & SD_NUMA) &&
+		    ((idlest_sgs.avg_load + imbalance) >= local_sgs.avg_load))
+			return NULL;
+
+		/*
+		 * If the local group is less loaded than the selected
+		 * idlest group don't try and push any tasks.
+		 */
+		if (idlest_sgs.avg_load >= (local_sgs.avg_load + imbalance))
+			return NULL;
+
+		if (100 * local_sgs.avg_load <= sd->imbalance_pct * idlest_sgs.avg_load)
+			return NULL;
+		break;
+
+	case group_imbalanced:
+	case group_asym_packing:
+		/* Those type are not used in the slow wakeup path */
+		return NULL;
+
+	case group_misfit_task:
+		/* Select group with the highest max capacity */
+		if (local->sgc->max_capacity >= idlest->sgc->max_capacity)
+			return NULL;
+		break;
+
+	case group_has_spare:
+		if (sd->flags & SD_NUMA) {
+#ifdef CONFIG_NUMA_BALANCING
+			int idlest_cpu;
+			/*
+			 * If there is spare capacity at NUMA, try to select
+			 * the preferred node
+			 */
+			if (cpu_to_node(this_cpu) == p->numa_preferred_nid)
+				return NULL;
+
+			idlest_cpu = cpumask_first(sched_group_span(idlest));
+			if (cpu_to_node(idlest_cpu) == p->numa_preferred_nid)
+				return idlest;
+#endif
+			/*
+			 * Otherwise, keep the task on this node to stay close
+			 * its wakeup source and improve locality. If there is
+			 * a real need of migration, periodic load balance will
+			 * take care of it.
+			 */
+			if (local_sgs.idle_cpus)
+				return NULL;
+		}
+
+		/*
+		 * Select group with highest number of idle CPUs. We could also
+		 * compare the utilization which is more stable but it can end
+		 * up that the group has less spare capacity but finally more
+		 * idle CPUs which means more opportunity to run task.
+		 */
+		if (local_sgs.idle_cpus >= idlest_sgs.idle_cpus)
+			return NULL;
+		break;
+	}
+
+	return idlest;
+}
+
 /**
  * update_sd_lb_stats - Update sched_domain's statistics for load balancing.
  * @env: The load balancing environment.
  * @sds: variable to hold the statistics for this sched_domain.
  */
+
 static inline void update_sd_lb_stats(struct lb_env *env, struct sd_lb_stats *sds)
 {
 	struct sched_domain *child = env->sd->child;
 	struct sched_group *sg = env->sd->groups;
 	struct sg_lb_stats *local = &sds->local_stat;
 	struct sg_lb_stats tmp_sgs;
-	bool prefer_sibling = child && child->flags & SD_PREFER_SIBLING;
 	int sg_status = 0;
 
 #ifdef CONFIG_NO_HZ_COMMON
@@ -8222,22 +8546,6 @@ static inline void update_sd_lb_stats(struct lb_env *env, struct sd_lb_stats *sd
 		if (local_group)
 			goto next_group;
 
-		/*
-		 * In case the child domain prefers tasks go to siblings
-		 * first, lower the sg capacity 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. 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 && sds->local &&
-		    group_has_capacity(env, local) &&
-		    (sgs->sum_nr_running > local->sum_nr_running + 1)) {
-			sgs->group_no_capacity = 1;
-			sgs->group_type = group_classify(sg, sgs);
-		}
 
 		if (update_sd_pick_busiest(env, sds, sg, sgs)) {
 			sds->busiest = sg;
@@ -8246,13 +8554,15 @@ static inline void update_sd_lb_stats(struct lb_env *env, struct sd_lb_stats *sd
 
 next_group:
 		/* Now, start updating sd_lb_stats */
-		sds->total_running += sgs->sum_nr_running;
 		sds->total_load += sgs->group_load;
 		sds->total_capacity += sgs->group_capacity;
 
 		sg = sg->next;
 	} while (sg != env->sd->groups);
 
+	/* Tag domain that child domain prefers tasks go to siblings first */
+	sds->prefer_sibling = child && child->flags & SD_PREFER_SIBLING;
+
 #ifdef CONFIG_NO_HZ_COMMON
 	if ((env->flags & LBF_NOHZ_AGAIN) &&
 	    cpumask_subset(nohz.idle_cpus_mask, sched_domain_span(env->sd))) {
@@ -8283,203 +8593,160 @@ next_group:
 }
 
 /**
- * check_asym_packing - Check to see if the group is packed into the
- *			sched domain.
- *
- * 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.
- *
- * Return: 1 when packing is required and a task should be moved to
- * this CPU.  The amount of the imbalance is returned in env->imbalance.
- *
- * @env: The load balancing environment.
- * @sds: Statistics of the sched_domain which is to be packed
- */
-static int check_asym_packing(struct lb_env *env, struct sd_lb_stats *sds)
-{
-	int busiest_cpu;
-
-	if (!(env->sd->flags & SD_ASYM_PACKING))
-		return 0;
-
-	if (env->idle == CPU_NOT_IDLE)
-		return 0;
-
-	if (!sds->busiest)
-		return 0;
-
-	busiest_cpu = sds->busiest->asym_prefer_cpu;
-	if (sched_asym_prefer(busiest_cpu, env->dst_cpu))
-		return 0;
-
-	env->imbalance = sds->busiest_stat.group_load;
-
-	return 1;
-}
-
-/**
- * fix_small_imbalance - Calculate the minor imbalance that exists
- *			amongst the groups of a sched_domain, during
- *			load balancing.
- * @env: The load balancing environment.
- * @sds: Statistics of the sched_domain whose imbalance is to be calculated.
+ * calculate_imbalance - Calculate the amount of imbalance present within the
+ *			 groups of a given sched_domain during load balance.
+ * @env: load balance environment
+ * @sds: statistics of the sched_domain whose imbalance is to be calculated.
  */
-static inline
-void fix_small_imbalance(struct lb_env *env, struct sd_lb_stats *sds)
+static inline void calculate_imbalance(struct lb_env *env, struct sd_lb_stats *sds)
 {
-	unsigned long tmp, capa_now = 0, capa_move = 0;
-	unsigned int imbn = 2;
-	unsigned long scaled_busy_load_per_task;
 	struct sg_lb_stats *local, *busiest;
 
 	local = &sds->local_stat;
 	busiest = &sds->busiest_stat;
 
-	if (!local->sum_nr_running)
-		local->load_per_task = cpu_avg_load_per_task(env->dst_cpu);
-	else if (busiest->load_per_task > local->load_per_task)
-		imbn = 1;
+	if (busiest->group_type == group_misfit_task) {
+		/* Set imbalance to allow misfit tasks to be balanced. */
+		env->migration_type = migrate_misfit;
+		env->imbalance = 1;
+		return;
+	}
 
-	scaled_busy_load_per_task =
-		(busiest->load_per_task * SCHED_CAPACITY_SCALE) /
-		busiest->group_capacity;
+	if (busiest->group_type == group_asym_packing) {
+		/*
+		 * In case of asym capacity, we will try to migrate all load to
+		 * the preferred CPU.
+		 */
+		env->migration_type = migrate_task;
+		env->imbalance = busiest->sum_h_nr_running;
+		return;
+	}
 
-	if (busiest->avg_load + scaled_busy_load_per_task >=
-	    local->avg_load + (scaled_busy_load_per_task * imbn)) {
-		env->imbalance = busiest->load_per_task;
+	if (busiest->group_type == group_imbalanced) {
+		/*
+		 * In the group_imb case we cannot rely on group-wide averages
+		 * to ensure CPU-load equilibrium, try to move any task to fix
+		 * the imbalance. The next load balance will take care of
+		 * balancing back the system.
+		 */
+		env->migration_type = migrate_task;
+		env->imbalance = 1;
 		return;
 	}
 
 	/*
-	 * OK, we don't have enough imbalance to justify moving tasks,
-	 * however we may be able to increase total CPU capacity used by
-	 * moving them.
+	 * Try to use spare capacity of local group without overloading it or
+	 * emptying busiest.
+	 * XXX Spreading tasks across NUMA nodes is not always the best policy
+	 * and special care should be taken for SD_NUMA domain level before
+	 * spreading the tasks. For now, load_balance() fully relies on
+	 * NUMA_BALANCING and fbq_classify_group/rq to override the decision.
 	 */
+	if (local->group_type == group_has_spare) {
+		if (busiest->group_type > group_fully_busy) {
+			/*
+			 * If busiest is overloaded, try to fill spare
+			 * capacity. This might end up creating spare capacity
+			 * in busiest or busiest still being overloaded but
+			 * there is no simple way to directly compute the
+			 * amount of load to migrate in order to balance the
+			 * system.
+			 */
+			env->migration_type = migrate_util;
+			env->imbalance = max(local->group_capacity, local->group_util) -
+					 local->group_util;
 
-	capa_now += busiest->group_capacity *
-			min(busiest->load_per_task, busiest->avg_load);
-	capa_now += local->group_capacity *
-			min(local->load_per_task, local->avg_load);
-	capa_now /= SCHED_CAPACITY_SCALE;
-
-	/* Amount of load we'd subtract */
-	if (busiest->avg_load > scaled_busy_load_per_task) {
-		capa_move += busiest->group_capacity *
-			    min(busiest->load_per_task,
-				busiest->avg_load - scaled_busy_load_per_task);
-	}
-
-	/* Amount of load we'd add */
-	if (busiest->avg_load * busiest->group_capacity <
-	    busiest->load_per_task * SCHED_CAPACITY_SCALE) {
-		tmp = (busiest->avg_load * busiest->group_capacity) /
-		      local->group_capacity;
-	} else {
-		tmp = (busiest->load_per_task * SCHED_CAPACITY_SCALE) /
-		      local->group_capacity;
-	}
-	capa_move += local->group_capacity *
-		    min(local->load_per_task, local->avg_load + tmp);
-	capa_move /= SCHED_CAPACITY_SCALE;
-
-	/* Move if we gain throughput */
-	if (capa_move > capa_now)
-		env->imbalance = busiest->load_per_task;
-}
+			/*
+			 * In some cases, the group's utilization is max or even
+			 * higher than capacity because of migrations but the
+			 * local CPU is (newly) idle. There is at least one
+			 * waiting task in this overloaded busiest group. Let's
+			 * try to pull it.
+			 */
+			if (env->idle != CPU_NOT_IDLE && env->imbalance == 0) {
+				env->migration_type = migrate_task;
+				env->imbalance = 1;
+			}
 
-/**
- * calculate_imbalance - Calculate the amount of imbalance present within the
- *			 groups of a given sched_domain during load balance.
- * @env: load balance environment
- * @sds: statistics of the sched_domain whose imbalance is to be calculated.
- */
-static inline void calculate_imbalance(struct lb_env *env, struct sd_lb_stats *sds)
-{
-	unsigned long max_pull, load_above_capacity = ~0UL;
-	struct sg_lb_stats *local, *busiest;
+			return;
+		}
 
-	local = &sds->local_stat;
-	busiest = &sds->busiest_stat;
+		if (busiest->group_weight == 1 || sds->prefer_sibling) {
+			unsigned int nr_diff = busiest->sum_nr_running;
+			/*
+			 * When prefer sibling, evenly spread running tasks on
+			 * groups.
+			 */
+			env->migration_type = migrate_task;
+			lsub_positive(&nr_diff, local->sum_nr_running);
+			env->imbalance = nr_diff >> 1;
+			return;
+		}
 
-	if (busiest->group_type == group_imbalanced) {
 		/*
-		 * In the group_imb case we cannot rely on group-wide averages
-		 * to ensure CPU-load equilibrium, look at wider averages. XXX
+		 * If there is no overload, we just want to even the number of
+		 * idle cpus.
 		 */
-		busiest->load_per_task =
-			min(busiest->load_per_task, sds->avg_load);
+		env->migration_type = migrate_task;
+		env->imbalance = max_t(long, 0, (local->idle_cpus -
+						 busiest->idle_cpus) >> 1);
+		return;
 	}
 
 	/*
-	 * Avg load of busiest sg can be less and avg load of local sg can
-	 * be greater than avg load across all sgs of sd because avg load
-	 * factors in sg capacity and sgs with smaller group_type are
-	 * skipped when updating the busiest sg:
+	 * Local is fully busy but has to take more load to relieve the
+	 * busiest group
 	 */
-	if (busiest->group_type != group_misfit_task &&
-	    (busiest->avg_load <= sds->avg_load ||
-	     local->avg_load >= sds->avg_load)) {
-		env->imbalance = 0;
-		return fix_small_imbalance(env, sds);
-	}
+	if (local->group_type < group_overloaded) {
+		/*
+		 * Local will become overloaded so the avg_load metrics are
+		 * finally needed.
+		 */
 
-	/*
-	 * If there aren't any idle CPUs, avoid creating some.
-	 */
-	if (busiest->group_type == group_overloaded &&
-	    local->group_type   == group_overloaded) {
-		load_above_capacity = busiest->sum_nr_running * SCHED_CAPACITY_SCALE;
-		if (load_above_capacity > busiest->group_capacity) {
-			load_above_capacity -= busiest->group_capacity;
-			load_above_capacity *= scale_load_down(NICE_0_LOAD);
-			load_above_capacity /= busiest->group_capacity;
-		} else
-			load_above_capacity = ~0UL;
+		local->avg_load = (local->group_load * SCHED_CAPACITY_SCALE) /
+				  local->group_capacity;
+
+		sds->avg_load = (sds->total_load * SCHED_CAPACITY_SCALE) /
+				sds->total_capacity;
 	}
 
 	/*
-	 * 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. Thus we look for the minimum possible imbalance.
+	 * Both group are or will become overloaded and 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. Thus we look for
+	 * the minimum possible imbalance.
 	 */
-	max_pull = min(busiest->avg_load - sds->avg_load, load_above_capacity);
-
-	/* How much load to actually move to equalise the imbalance */
+	env->migration_type = migrate_load;
 	env->imbalance = min(
-		max_pull * busiest->group_capacity,
+		(busiest->avg_load - sds->avg_load) * busiest->group_capacity,
 		(sds->avg_load - local->avg_load) * local->group_capacity
 	) / SCHED_CAPACITY_SCALE;
-
-	/* Boost imbalance to allow misfit task to be balanced. */
-	if (busiest->group_type == group_misfit_task) {
-		env->imbalance = max_t(long, env->imbalance,
-				       busiest->group_misfit_task_load);
-	}
-
-	/*
-	 * 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 (env->imbalance < busiest->load_per_task)
-		return fix_small_imbalance(env, sds);
 }
 
 /******* find_busiest_group() helpers end here *********************/
 
+/*
+ * Decision matrix according to the local and busiest group type:
+ *
+ * busiest \ local has_spare fully_busy misfit asym imbalanced overloaded
+ * has_spare        nr_idle   balanced   N/A    N/A  balanced   balanced
+ * fully_busy       nr_idle   nr_idle    N/A    N/A  balanced   balanced
+ * misfit_task      force     N/A        N/A    N/A  force      force
+ * asym_packing     force     force      N/A    N/A  force      force
+ * imbalanced       force     force      N/A    N/A  force      force
+ * overloaded       force     force      N/A    N/A  force      avg_load
+ *
+ * N/A :      Not Applicable because already filtered while updating
+ *            statistics.
+ * balanced : The system is balanced for these 2 groups.
+ * force :    Calculate the imbalance as load migration is probably needed.
+ * avg_load : Only if imbalance is significant enough.
+ * nr_idle :  dst_cpu is not busy and the number of idle CPUs is quite
+ *            different in groups.
+ */
+
 /**
  * find_busiest_group - Returns the busiest group within the sched_domain
  * if there is an imbalance.
@@ -8499,7 +8766,7 @@ static struct sched_group *find_busiest_group(struct lb_env *env)
 	init_sd_lb_stats(&sds);
 
 	/*
-	 * Compute the various statistics relavent for load balancing at
+	 * Compute the various statistics relevant for load balancing at
 	 * this level.
 	 */
 	update_sd_lb_stats(env, &sds);
@@ -8514,17 +8781,17 @@ static struct sched_group *find_busiest_group(struct lb_env *env)
 	local = &sds.local_stat;
 	busiest = &sds.busiest_stat;
 
-	/* ASYM feature bypasses nice load balance check */
-	if (check_asym_packing(env, &sds))
-		return sds.busiest;
-
 	/* There is no busy sibling group to pull tasks from */
-	if (!sds.busiest || busiest->sum_nr_running == 0)
+	if (!sds.busiest)
 		goto out_balanced;
 
-	/* XXX broken for overlapping NUMA groups */
-	sds.avg_load = (SCHED_CAPACITY_SCALE * sds.total_load)
-						/ sds.total_capacity;
+	/* Misfit tasks should be dealt with regardless of the avg load */
+	if (busiest->group_type == group_misfit_task)
+		goto force_balance;
+
+	/* ASYM feature bypasses nice load balance check */
+	if (busiest->group_type == group_asym_packing)
+		goto force_balance;
 
 	/*
 	 * If the busiest group is imbalanced the below checks don't
@@ -8535,55 +8802,80 @@ static struct sched_group *find_busiest_group(struct lb_env *env)
 		goto force_balance;
 
 	/*
-	 * When dst_cpu is idle, prevent SMP nice and/or asymmetric group
-	 * capacities from resulting in underutilization due to avg_load.
-	 */
-	if (env->idle != CPU_NOT_IDLE && group_has_capacity(env, local) &&
-	    busiest->group_no_capacity)
-		goto force_balance;
-
-	/* Misfit tasks should be dealt with regardless of the avg load */
-	if (busiest->group_type == group_misfit_task)
-		goto force_balance;
-
-	/*
 	 * If the local group is busier than the selected busiest group
 	 * don't try and pull any tasks.
 	 */
-	if (local->avg_load >= busiest->avg_load)
+	if (local->group_type > busiest->group_type)
 		goto out_balanced;
 
 	/*
-	 * Don't pull any tasks if this group is already above the domain
-	 * average load.
+	 * When groups are overloaded, use the avg_load to ensure fairness
+	 * between tasks.
 	 */
-	if (local->avg_load >= sds.avg_load)
-		goto out_balanced;
+	if (local->group_type == group_overloaded) {
+		/*
+		 * If the local group is more loaded than the selected
+		 * busiest group don't try to pull any tasks.
+		 */
+		if (local->avg_load >= busiest->avg_load)
+			goto out_balanced;
+
+		/* XXX broken for overlapping NUMA groups */
+		sds.avg_load = (sds.total_load * SCHED_CAPACITY_SCALE) /
+				sds.total_capacity;
 
-	if (env->idle == CPU_IDLE) {
 		/*
-		 * This CPU is idle. If the busiest group is not overloaded
-		 * and there is no imbalance between this and busiest group
-		 * wrt idle CPUs, it is balanced. The imbalance becomes
-		 * significant if the diff is greater than 1 otherwise we
-		 * might end up to just move the imbalance on another group
+		 * Don't pull any tasks if this group is already above the
+		 * domain average load.
 		 */
-		if ((busiest->group_type != group_overloaded) &&
-				(local->idle_cpus <= (busiest->idle_cpus + 1)))
+		if (local->avg_load >= sds.avg_load)
 			goto out_balanced;
-	} else {
+
 		/*
-		 * In the CPU_NEWLY_IDLE, CPU_NOT_IDLE cases, use
-		 * imbalance_pct to be conservative.
+		 * If the busiest group is more loaded, use imbalance_pct to be
+		 * conservative.
 		 */
 		if (100 * busiest->avg_load <=
 				env->sd->imbalance_pct * local->avg_load)
 			goto out_balanced;
 	}
 
+	/* Try to move all excess tasks to child's sibling domain */
+	if (sds.prefer_sibling && local->group_type == group_has_spare &&
+	    busiest->sum_nr_running > local->sum_nr_running + 1)
+		goto force_balance;
+
+	if (busiest->group_type != group_overloaded) {
+		if (env->idle == CPU_NOT_IDLE)
+			/*
+			 * If the busiest group is not overloaded (and as a
+			 * result the local one too) but this CPU is already
+			 * busy, let another idle CPU try to pull task.
+			 */
+			goto out_balanced;
+
+		if (busiest->group_weight > 1 &&
+		    local->idle_cpus <= (busiest->idle_cpus + 1))
+			/*
+			 * If the busiest group is not overloaded
+			 * and there is no imbalance between this and busiest
+			 * group wrt idle CPUs, it is balanced. The imbalance
+			 * becomes significant if the diff is greater than 1
+			 * otherwise we might end up to just move the imbalance
+			 * on another group. Of course this applies only if
+			 * there is more than 1 CPU per group.
+			 */
+			goto out_balanced;
+
+		if (busiest->sum_h_nr_running == 1)
+			/*
+			 * busiest doesn't have any tasks waiting to run
+			 */
+			goto out_balanced;
+	}
+
 force_balance:
 	/* Looks like there is an imbalance. Compute it */
-	env->src_grp_type = busiest->group_type;
 	calculate_imbalance(env, &sds);
 	return env->imbalance ? sds.busiest : NULL;
 
@@ -8599,11 +8891,13 @@ static struct rq *find_busiest_queue(struct lb_env *env,
 				     struct sched_group *group)
 {
 	struct rq *busiest = NULL, *rq;
-	unsigned long busiest_load = 0, busiest_capacity = 1;
+	unsigned long busiest_util = 0, busiest_load = 0, busiest_capacity = 1;
+	unsigned int busiest_nr = 0;
 	int i;
 
 	for_each_cpu_and(i, sched_group_span(group), env->cpus) {
-		unsigned long capacity, load;
+		unsigned long capacity, load, util;
+		unsigned int nr_running;
 		enum fbq_type rt;
 
 		rq = cpu_rq(i);
@@ -8631,20 +8925,8 @@ static struct rq *find_busiest_queue(struct lb_env *env,
 		if (rt > env->fbq_type)
 			continue;
 
-		/*
-		 * For ASYM_CPUCAPACITY domains with misfit tasks we simply
-		 * seek the "biggest" misfit task.
-		 */
-		if (env->src_grp_type == group_misfit_task) {
-			if (rq->misfit_task_load > busiest_load) {
-				busiest_load = rq->misfit_task_load;
-				busiest = rq;
-			}
-
-			continue;
-		}
-
 		capacity = capacity_of(i);
+		nr_running = rq->cfs.h_nr_running;
 
 		/*
 		 * For ASYM_CPUCAPACITY domains, don't pick a CPU that could
@@ -8654,35 +8936,69 @@ static struct rq *find_busiest_queue(struct lb_env *env,
 		 */
 		if (env->sd->flags & SD_ASYM_CPUCAPACITY &&
 		    capacity_of(env->dst_cpu) < capacity &&
-		    rq->nr_running == 1)
+		    nr_running == 1)
 			continue;
 
-		load = cpu_runnable_load(rq);
+		switch (env->migration_type) {
+		case migrate_load:
+			/*
+			 * When comparing with load imbalance, use cpu_load()
+			 * which is not scaled with the CPU capacity.
+			 */
+			load = cpu_load(rq);
 
-		/*
-		 * When comparing with imbalance, use cpu_runnable_load()
-		 * which is not scaled with the CPU capacity.
-		 */
+			if (nr_running == 1 && load > env->imbalance &&
+			    !check_cpu_capacity(rq, env->sd))
+				break;
 
-		if (rq->nr_running == 1 && load > env->imbalance &&
-		    !check_cpu_capacity(rq, env->sd))
-			continue;
+			/*
+			 * For the load comparisons with the other CPUs,
+			 * consider the cpu_load() scaled with the CPU
+			 * capacity, so that the load can be moved away
+			 * from the CPU that is potentially running at a
+			 * lower capacity.
+			 *
+			 * Thus we're looking for max(load_i / capacity_i),
+			 * crosswise multiplication to rid ourselves of the
+			 * division works out to:
+			 * load_i * capacity_j > load_j * capacity_i;
+			 * where j is our previous maximum.
+			 */
+			if (load * busiest_capacity > busiest_load * capacity) {
+				busiest_load = load;
+				busiest_capacity = capacity;
+				busiest = rq;
+			}
+			break;
+
+		case migrate_util:
+			util = cpu_util(cpu_of(rq));
+
+			if (busiest_util < util) {
+				busiest_util = util;
+				busiest = rq;
+			}
+			break;
+
+		case migrate_task:
+			if (busiest_nr < nr_running) {
+				busiest_nr = nr_running;
+				busiest = rq;
+			}
+			break;
+
+		case migrate_misfit:
+			/*
+			 * For ASYM_CPUCAPACITY domains with misfit tasks we
+			 * simply seek the "biggest" misfit task.
+			 */
+			if (rq->misfit_task_load > busiest_load) {
+				busiest_load = rq->misfit_task_load;
+				busiest = rq;
+			}
+
+			break;
 
-		/*
-		 * For the load comparisons with the other CPU's, consider
-		 * the cpu_runnable_load() scaled with the CPU capacity, so
-		 * that the load can be moved away from the CPU that is
-		 * potentially running at a lower capacity.
-		 *
-		 * Thus we're looking for max(load_i / capacity_i), crosswise
-		 * multiplication to rid ourselves of the division works out
-		 * to: load_i * capacity_j > load_j * capacity_i;  where j is
-		 * our previous maximum.
-		 */
-		if (load * busiest_capacity > busiest_load * capacity) {
-			busiest_load = load;
-			busiest_capacity = capacity;
-			busiest = rq;
 		}
 	}
 
@@ -8728,7 +9044,7 @@ voluntary_active_balance(struct lb_env *env)
 			return 1;
 	}
 
-	if (env->src_grp_type == group_misfit_task)
+	if (env->migration_type == migrate_misfit)
 		return 1;
 
 	return 0;
@@ -9757,6 +10073,11 @@ static inline void nohz_newidle_balance(struct rq *this_rq) { }
 /*
  * idle_balance is called by schedule() if this_cpu is about to become
  * idle. Attempts to pull tasks from other CPUs.
+ *
+ * Returns:
+ *   < 0 - we released the lock and there are !fair tasks present
+ *     0 - failed, no new tasks
+ *   > 0 - success, new (fair) tasks present
  */
 int newidle_balance(struct rq *this_rq, struct rq_flags *rf)
 {
@@ -10151,7 +10472,7 @@ static void switched_to_fair(struct rq *rq, struct task_struct *p)
  * This routine is mostly called to set cfs_rq->curr field when a task
  * migrates between groups/classes.
  */
-static void set_next_task_fair(struct rq *rq, struct task_struct *p)
+static void set_next_task_fair(struct rq *rq, struct task_struct *p, bool first)
 {
 	struct sched_entity *se = &p->se;
 
@@ -10433,7 +10754,7 @@ const struct sched_class fair_sched_class = {
 
 	.check_preempt_curr	= check_preempt_wakeup,
 
-	.pick_next_task		= pick_next_task_fair,
+	.pick_next_task		= __pick_next_task_fair,
 	.put_prev_task		= put_prev_task_fair,
 	.set_next_task          = set_next_task_fair,
 
diff --git a/kernel/sched/features.h b/kernel/sched/features.h
index 2410db5e9a35..7481cd96f391 100644
--- a/kernel/sched/features.h
+++ b/kernel/sched/features.h
@@ -89,3 +89,4 @@ SCHED_FEAT(WA_BIAS, true)
  * UtilEstimation. Use estimated CPU utilization.
  */
 SCHED_FEAT(UTIL_EST, true)
+SCHED_FEAT(UTIL_EST_FASTUP, true)
diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c
index f65ef1e2f204..428cd05c0b5d 100644
--- a/kernel/sched/idle.c
+++ b/kernel/sched/idle.c
@@ -385,21 +385,17 @@ static void put_prev_task_idle(struct rq *rq, struct task_struct *prev)
 {
 }
 
-static void set_next_task_idle(struct rq *rq, struct task_struct *next)
+static void set_next_task_idle(struct rq *rq, struct task_struct *next, bool first)
 {
 	update_idle_core(rq);
 	schedstat_inc(rq->sched_goidle);
 }
 
-static struct task_struct *
-pick_next_task_idle(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
+struct task_struct *pick_next_task_idle(struct rq *rq)
 {
 	struct task_struct *next = rq->idle;
 
-	if (prev)
-		put_prev_task(rq, prev);
-
-	set_next_task_idle(rq, next);
+	set_next_task_idle(rq, next, true);
 
 	return next;
 }
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index 9b8adc01be3d..e591d40fd645 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -1515,13 +1515,16 @@ static void check_preempt_curr_rt(struct rq *rq, struct task_struct *p, int flag
 #endif
 }
 
-static inline void set_next_task_rt(struct rq *rq, struct task_struct *p)
+static inline void set_next_task_rt(struct rq *rq, struct task_struct *p, bool first)
 {
 	p->se.exec_start = rq_clock_task(rq);
 
 	/* The running task is never eligible for pushing */
 	dequeue_pushable_task(rq, p);
 
+	if (!first)
+		return;
+
 	/*
 	 * If prev task was rt, put_prev_task() has already updated the
 	 * utilization. We only care of the case where we start to schedule a
@@ -1564,18 +1567,15 @@ static struct task_struct *_pick_next_task_rt(struct rq *rq)
 	return rt_task_of(rt_se);
 }
 
-static struct task_struct *
-pick_next_task_rt(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
+static struct task_struct *pick_next_task_rt(struct rq *rq)
 {
 	struct task_struct *p;
 
-	WARN_ON_ONCE(prev || rf);
-
 	if (!sched_rt_runnable(rq))
 		return NULL;
 
 	p = _pick_next_task_rt(rq);
-	set_next_task_rt(rq, p);
+	set_next_task_rt(rq, p, true);
 	return p;
 }
 
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index c8870c5bd7df..280a3c735935 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -1713,22 +1713,10 @@ struct sched_class {
 
 	void (*check_preempt_curr)(struct rq *rq, struct task_struct *p, int flags);
 
-	/*
-	 * Both @prev and @rf are optional and may be NULL, in which case the
-	 * caller must already have invoked put_prev_task(rq, prev, rf).
-	 *
-	 * Otherwise it is the responsibility of the pick_next_task() to call
-	 * put_prev_task() on the @prev task or something equivalent, IFF it
-	 * returns a next task.
-	 *
-	 * In that case (@rf != NULL) it may return RETRY_TASK when it finds a
-	 * higher prio class has runnable tasks.
-	 */
-	struct task_struct * (*pick_next_task)(struct rq *rq,
-					       struct task_struct *prev,
-					       struct rq_flags *rf);
+	struct task_struct *(*pick_next_task)(struct rq *rq);
+
 	void (*put_prev_task)(struct rq *rq, struct task_struct *p);
-	void (*set_next_task)(struct rq *rq, struct task_struct *p);
+	void (*set_next_task)(struct rq *rq, struct task_struct *p, bool first);
 
 #ifdef CONFIG_SMP
 	int (*balance)(struct rq *rq, struct task_struct *prev, struct rq_flags *rf);
@@ -1780,7 +1768,7 @@ static inline void put_prev_task(struct rq *rq, struct task_struct *prev)
 static inline void set_next_task(struct rq *rq, struct task_struct *next)
 {
 	WARN_ON_ONCE(rq->curr != next);
-	next->sched_class->set_next_task(rq, next);
+	next->sched_class->set_next_task(rq, next, false);
 }
 
 #ifdef CONFIG_SMP
@@ -1821,6 +1809,9 @@ static inline bool sched_fair_runnable(struct rq *rq)
 	return rq->cfs.nr_running > 0;
 }
 
+extern struct task_struct *pick_next_task_fair(struct rq *rq, struct task_struct *prev, struct rq_flags *rf);
+extern struct task_struct *pick_next_task_idle(struct rq *rq);
+
 #ifdef CONFIG_SMP
 
 extern void update_group_capacity(struct sched_domain *sd, int cpu);
@@ -2309,7 +2300,7 @@ static inline void cpufreq_update_util(struct rq *rq, unsigned int flags) {}
 #endif /* CONFIG_CPU_FREQ */
 
 #ifdef CONFIG_UCLAMP_TASK
-enum uclamp_id uclamp_eff_value(struct task_struct *p, enum uclamp_id clamp_id);
+unsigned int uclamp_eff_value(struct task_struct *p, enum uclamp_id clamp_id);
 
 static __always_inline
 unsigned int uclamp_util_with(struct rq *rq, unsigned int util,
diff --git a/kernel/sched/stop_task.c b/kernel/sched/stop_task.c
index c0640739e05e..4c9e9975684f 100644
--- a/kernel/sched/stop_task.c
+++ b/kernel/sched/stop_task.c
@@ -29,20 +29,17 @@ check_preempt_curr_stop(struct rq *rq, struct task_struct *p, int flags)
 	/* we're never preempted */
 }
 
-static void set_next_task_stop(struct rq *rq, struct task_struct *stop)
+static void set_next_task_stop(struct rq *rq, struct task_struct *stop, bool first)
 {
 	stop->se.exec_start = rq_clock_task(rq);
 }
 
-static struct task_struct *
-pick_next_task_stop(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
+static struct task_struct *pick_next_task_stop(struct rq *rq)
 {
-	WARN_ON_ONCE(prev || rf);
-
 	if (!sched_stop_runnable(rq))
 		return NULL;
 
-	set_next_task_stop(rq, rq->stop);
+	set_next_task_stop(rq, rq->stop, true);
 	return rq->stop;
 }
 
diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
index 49b835f1305f..6ec1e595b1d4 100644
--- a/kernel/sched/topology.c
+++ b/kernel/sched/topology.c
@@ -1201,16 +1201,13 @@ static void set_domain_attribute(struct sched_domain *sd,
 	if (!attr || attr->relax_domain_level < 0) {
 		if (default_relax_domain_level < 0)
 			return;
-		else
-			request = default_relax_domain_level;
+		request = default_relax_domain_level;
 	} else
 		request = attr->relax_domain_level;
-	if (request < sd->level) {
+
+	if (sd->level > request) {
 		/* Turn off idle balance on this domain: */
 		sd->flags &= ~(SD_BALANCE_WAKE|SD_BALANCE_NEWIDLE);
-	} else {
-		/* Turn on idle balance on this domain: */
-		sd->flags |= (SD_BALANCE_WAKE|SD_BALANCE_NEWIDLE);
 	}
 }
 
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 955851748dc3..c2748232f607 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -1119,7 +1119,7 @@ static void tick_nohz_account_idle_ticks(struct tick_sched *ts)
 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
 	unsigned long ticks;
 
-	if (vtime_accounting_cpu_enabled())
+	if (vtime_accounting_enabled_this_cpu())
 		return;
 	/*
 	 * We stopped the tick in idle. Update process times would miss the