1 files changed, 302 insertions, 161 deletions

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index c95880e216f6..8bc0a883d190 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -806,7 +806,7 @@ void post_init_entity_util_avg(struct sched_entity *se)
 			/*
 			 * For !fair tasks do:
 			 *
-			update_cfs_rq_load_avg(now, cfs_rq, false);
+			update_cfs_rq_load_avg(now, cfs_rq);
 			attach_entity_load_avg(cfs_rq, se);
 			switched_from_fair(rq, p);
 			 *
@@ -1071,6 +1071,29 @@ unsigned int sysctl_numa_balancing_scan_size = 256;
 /* Scan @scan_size MB every @scan_period after an initial @scan_delay in ms */
 unsigned int sysctl_numa_balancing_scan_delay = 1000;
 
+struct numa_group {
+	atomic_t refcount;
+
+	spinlock_t lock; /* nr_tasks, tasks */
+	int nr_tasks;
+	pid_t gid;
+	int active_nodes;
+
+	struct rcu_head rcu;
+	unsigned long total_faults;
+	unsigned long max_faults_cpu;
+	/*
+	 * Faults_cpu is used to decide whether memory should move
+	 * towards the CPU. As a consequence, these stats are weighted
+	 * more by CPU use than by memory faults.
+	 */
+	unsigned long *faults_cpu;
+	unsigned long faults[0];
+};
+
+static inline unsigned long group_faults_priv(struct numa_group *ng);
+static inline unsigned long group_faults_shared(struct numa_group *ng);
+
 static unsigned int task_nr_scan_windows(struct task_struct *p)
 {
 	unsigned long rss = 0;
@@ -1107,13 +1130,47 @@ static unsigned int task_scan_min(struct task_struct *p)
 	return max_t(unsigned int, floor, scan);
 }
 
+static unsigned int task_scan_start(struct task_struct *p)
+{
+	unsigned long smin = task_scan_min(p);
+	unsigned long period = smin;
+
+	/* Scale the maximum scan period with the amount of shared memory. */
+	if (p->numa_group) {
+		struct numa_group *ng = p->numa_group;
+		unsigned long shared = group_faults_shared(ng);
+		unsigned long private = group_faults_priv(ng);
+
+		period *= atomic_read(&ng->refcount);
+		period *= shared + 1;
+		period /= private + shared + 1;
+	}
+
+	return max(smin, period);
+}
+
 static unsigned int task_scan_max(struct task_struct *p)
 {
-	unsigned int smin = task_scan_min(p);
-	unsigned int smax;
+	unsigned long smin = task_scan_min(p);
+	unsigned long smax;
 
 	/* Watch for min being lower than max due to floor calculations */
 	smax = sysctl_numa_balancing_scan_period_max / task_nr_scan_windows(p);
+
+	/* Scale the maximum scan period with the amount of shared memory. */
+	if (p->numa_group) {
+		struct numa_group *ng = p->numa_group;
+		unsigned long shared = group_faults_shared(ng);
+		unsigned long private = group_faults_priv(ng);
+		unsigned long period = smax;
+
+		period *= atomic_read(&ng->refcount);
+		period *= shared + 1;
+		period /= private + shared + 1;
+
+		smax = max(smax, period);
+	}
+
 	return max(smin, smax);
 }
 
@@ -1129,26 +1186,6 @@ static void account_numa_dequeue(struct rq *rq, struct task_struct *p)
 	rq->nr_preferred_running -= (p->numa_preferred_nid == task_node(p));
 }
 
-struct numa_group {
-	atomic_t refcount;
-
-	spinlock_t lock; /* nr_tasks, tasks */
-	int nr_tasks;
-	pid_t gid;
-	int active_nodes;
-
-	struct rcu_head rcu;
-	unsigned long total_faults;
-	unsigned long max_faults_cpu;
-	/*
-	 * Faults_cpu is used to decide whether memory should move
-	 * towards the CPU. As a consequence, these stats are weighted
-	 * more by CPU use than by memory faults.
-	 */
-	unsigned long *faults_cpu;
-	unsigned long faults[0];
-};
-
 /* Shared or private faults. */
 #define NR_NUMA_HINT_FAULT_TYPES 2
 
@@ -1198,6 +1235,30 @@ static inline unsigned long group_faults_cpu(struct numa_group *group, int nid)
 		group->faults_cpu[task_faults_idx(NUMA_MEM, nid, 1)];
 }
 
+static inline unsigned long group_faults_priv(struct numa_group *ng)
+{
+	unsigned long faults = 0;
+	int node;
+
+	for_each_online_node(node) {
+		faults += ng->faults[task_faults_idx(NUMA_MEM, node, 1)];
+	}
+
+	return faults;
+}
+
+static inline unsigned long group_faults_shared(struct numa_group *ng)
+{
+	unsigned long faults = 0;
+	int node;
+
+	for_each_online_node(node) {
+		faults += ng->faults[task_faults_idx(NUMA_MEM, node, 0)];
+	}
+
+	return faults;
+}
+
 /*
  * A node triggering more than 1/3 as many NUMA faults as the maximum is
  * considered part of a numa group's pseudo-interleaving set. Migrations
@@ -1378,7 +1439,7 @@ 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 weighted_cpuload(const int cpu);
+static unsigned long weighted_cpuload(struct rq *rq);
 static unsigned long source_load(int cpu, int type);
 static unsigned long target_load(int cpu, int type);
 static unsigned long capacity_of(int cpu);
@@ -1409,7 +1470,7 @@ static void update_numa_stats(struct numa_stats *ns, int nid)
 		struct rq *rq = cpu_rq(cpu);
 
 		ns->nr_running += rq->nr_running;
-		ns->load += weighted_cpuload(cpu);
+		ns->load += weighted_cpuload(rq);
 		ns->compute_capacity += capacity_of(cpu);
 
 		cpus++;
@@ -1808,7 +1869,7 @@ static int task_numa_migrate(struct task_struct *p)
 	 * Reset the scan period if the task is being rescheduled on an
 	 * alternative node to recheck if the tasks is now properly placed.
 	 */
-	p->numa_scan_period = task_scan_min(p);
+	p->numa_scan_period = task_scan_start(p);
 
 	if (env.best_task == NULL) {
 		ret = migrate_task_to(p, env.best_cpu);
@@ -1892,7 +1953,7 @@ static void update_task_scan_period(struct task_struct *p,
 			unsigned long shared, unsigned long private)
 {
 	unsigned int period_slot;
-	int ratio;
+	int lr_ratio, ps_ratio;
 	int diff;
 
 	unsigned long remote = p->numa_faults_locality[0];
@@ -1922,25 +1983,36 @@ static void update_task_scan_period(struct task_struct *p,
 	 *	 >= NUMA_PERIOD_THRESHOLD scan period increases (scan slower)
 	 */
 	period_slot = DIV_ROUND_UP(p->numa_scan_period, NUMA_PERIOD_SLOTS);
-	ratio = (local * NUMA_PERIOD_SLOTS) / (local + remote);
-	if (ratio >= NUMA_PERIOD_THRESHOLD) {
-		int slot = ratio - NUMA_PERIOD_THRESHOLD;
+	lr_ratio = (local * NUMA_PERIOD_SLOTS) / (local + remote);
+	ps_ratio = (private * NUMA_PERIOD_SLOTS) / (private + shared);
+
+	if (ps_ratio >= NUMA_PERIOD_THRESHOLD) {
+		/*
+		 * Most memory accesses are local. There is no need to
+		 * do fast NUMA scanning, since memory is already local.
+		 */
+		int slot = ps_ratio - NUMA_PERIOD_THRESHOLD;
+		if (!slot)
+			slot = 1;
+		diff = slot * period_slot;
+	} else if (lr_ratio >= NUMA_PERIOD_THRESHOLD) {
+		/*
+		 * Most memory accesses are shared with other tasks.
+		 * There is no point in continuing fast NUMA scanning,
+		 * since other tasks may just move the memory elsewhere.
+		 */
+		int slot = lr_ratio - NUMA_PERIOD_THRESHOLD;
 		if (!slot)
 			slot = 1;
 		diff = slot * period_slot;
 	} else {
-		diff = -(NUMA_PERIOD_THRESHOLD - ratio) * period_slot;
-
 		/*
-		 * Scale scan rate increases based on sharing. There is an
-		 * inverse relationship between the degree of sharing and
-		 * the adjustment made to the scanning period. Broadly
-		 * speaking the intent is that there is little point
-		 * scanning faster if shared accesses dominate as it may
-		 * simply bounce migrations uselessly
+		 * Private memory faults exceed (SLOTS-THRESHOLD)/SLOTS,
+		 * yet they are not on the local NUMA node. Speed up
+		 * NUMA scanning to get the memory moved over.
 		 */
-		ratio = DIV_ROUND_UP(private * NUMA_PERIOD_SLOTS, (private + shared + 1));
-		diff = (diff * ratio) / NUMA_PERIOD_SLOTS;
+		int ratio = max(lr_ratio, ps_ratio);
+		diff = -(NUMA_PERIOD_THRESHOLD - ratio) * period_slot;
 	}
 
 	p->numa_scan_period = clamp(p->numa_scan_period + diff,
@@ -2448,7 +2520,7 @@ void task_numa_work(struct callback_head *work)
 
 	if (p->numa_scan_period == 0) {
 		p->numa_scan_period_max = task_scan_max(p);
-		p->numa_scan_period = task_scan_min(p);
+		p->numa_scan_period = task_scan_start(p);
 	}
 
 	next_scan = now + msecs_to_jiffies(p->numa_scan_period);
@@ -2576,7 +2648,7 @@ void task_tick_numa(struct rq *rq, struct task_struct *curr)
 
 	if (now > curr->node_stamp + period) {
 		if (!curr->node_stamp)
-			curr->numa_scan_period = task_scan_min(curr);
+			curr->numa_scan_period = task_scan_start(curr);
 		curr->node_stamp += period;
 
 		if (!time_before(jiffies, curr->mm->numa_next_scan)) {
@@ -2586,59 +2658,6 @@ void task_tick_numa(struct rq *rq, struct task_struct *curr)
 	}
 }
 
-/*
- * Can a task be moved from prev_cpu to this_cpu without causing a load
- * imbalance that would trigger the load balancer?
- */
-static inline bool numa_wake_affine(struct sched_domain *sd,
-				    struct task_struct *p, int this_cpu,
-				    int prev_cpu, int sync)
-{
-	struct numa_stats prev_load, this_load;
-	s64 this_eff_load, prev_eff_load;
-
-	update_numa_stats(&prev_load, cpu_to_node(prev_cpu));
-	update_numa_stats(&this_load, cpu_to_node(this_cpu));
-
-	/*
-	 * If sync wakeup then subtract the (maximum possible)
-	 * effect of the currently running task from the load
-	 * of the current CPU:
-	 */
-	if (sync) {
-		unsigned long current_load = task_h_load(current);
-
-		if (this_load.load > current_load)
-			this_load.load -= current_load;
-		else
-			this_load.load = 0;
-	}
-
-	/*
-	 * In low-load situations, where this_cpu's node is idle due to the
-	 * sync cause above having dropped this_load.load to 0, move the task.
-	 * Moving to an idle socket will not create a bad imbalance.
-	 *
-	 * Otherwise check if the nodes are near enough in load to allow this
-	 * task to be woken on this_cpu's node.
-	 */
-	if (this_load.load > 0) {
-		unsigned long task_load = task_h_load(p);
-
-		this_eff_load = 100;
-		this_eff_load *= prev_load.compute_capacity;
-
-		prev_eff_load = 100 + (sd->imbalance_pct - 100) / 2;
-		prev_eff_load *= this_load.compute_capacity;
-
-		this_eff_load *= this_load.load + task_load;
-		prev_eff_load *= prev_load.load - task_load;
-
-		return this_eff_load <= prev_eff_load;
-	}
-
-	return true;
-}
 #else
 static void task_tick_numa(struct rq *rq, struct task_struct *curr)
 {
@@ -2652,14 +2671,6 @@ static inline void account_numa_dequeue(struct rq *rq, struct task_struct *p)
 {
 }
 
-#ifdef CONFIG_SMP
-static inline bool numa_wake_affine(struct sched_domain *sd,
-				    struct task_struct *p, int this_cpu,
-				    int prev_cpu, int sync)
-{
-	return true;
-}
-#endif /* !SMP */
 #endif /* CONFIG_NUMA_BALANCING */
 
 static void
@@ -2790,6 +2801,31 @@ static inline void update_cfs_shares(struct sched_entity *se)
 }
 #endif /* CONFIG_FAIR_GROUP_SCHED */
 
+static inline void cfs_rq_util_change(struct cfs_rq *cfs_rq)
+{
+	struct rq *rq = rq_of(cfs_rq);
+
+	if (&rq->cfs == cfs_rq) {
+		/*
+		 * There are a few boundary cases this might miss but it should
+		 * get called often enough that that should (hopefully) not be
+		 * a real problem -- added to that it only calls on the local
+		 * CPU, so if we enqueue remotely we'll miss an update, but
+		 * the next tick/schedule should update.
+		 *
+		 * It will not get called when we go idle, because the idle
+		 * thread is a different class (!fair), nor will the utilization
+		 * number include things like RT tasks.
+		 *
+		 * As is, the util number is not freq-invariant (we'd have to
+		 * implement arch_scale_freq_capacity() for that).
+		 *
+		 * See cpu_util().
+		 */
+		cpufreq_update_util(rq, 0);
+	}
+}
+
 #ifdef CONFIG_SMP
 /*
  * Approximate:
@@ -2968,6 +3004,18 @@ ___update_load_avg(u64 now, int cpu, struct sched_avg *sa,
 	sa->last_update_time += delta << 10;
 
 	/*
+	 * running is a subset of runnable (weight) so running can't be set if
+	 * runnable is clear. But there are some corner cases where the current
+	 * se has been already dequeued but cfs_rq->curr still points to it.
+	 * This means that weight will be 0 but not running for a sched_entity
+	 * but also for a cfs_rq if the latter becomes idle. As an example,
+	 * this happens during idle_balance() which calls
+	 * update_blocked_averages()
+	 */
+	if (!weight)
+		running = 0;
+
+	/*
 	 * Now we know we crossed measurement unit boundaries. The *_avg
 	 * accrues by two steps:
 	 *
@@ -3276,29 +3324,6 @@ static inline void set_tg_cfs_propagate(struct cfs_rq *cfs_rq) {}
 
 #endif /* CONFIG_FAIR_GROUP_SCHED */
 
-static inline void cfs_rq_util_change(struct cfs_rq *cfs_rq)
-{
-	if (&this_rq()->cfs == cfs_rq) {
-		/*
-		 * There are a few boundary cases this might miss but it should
-		 * get called often enough that that should (hopefully) not be
-		 * a real problem -- added to that it only calls on the local
-		 * CPU, so if we enqueue remotely we'll miss an update, but
-		 * the next tick/schedule should update.
-		 *
-		 * It will not get called when we go idle, because the idle
-		 * thread is a different class (!fair), nor will the utilization
-		 * number include things like RT tasks.
-		 *
-		 * As is, the util number is not freq-invariant (we'd have to
-		 * implement arch_scale_freq_capacity() for that).
-		 *
-		 * See cpu_util().
-		 */
-		cpufreq_update_util(rq_of(cfs_rq), 0);
-	}
-}
-
 /*
  * Unsigned subtract and clamp on underflow.
  *
@@ -3320,7 +3345,6 @@ static inline void cfs_rq_util_change(struct cfs_rq *cfs_rq)
  * update_cfs_rq_load_avg - update the cfs_rq's load/util averages
  * @now: current time, as per cfs_rq_clock_task()
  * @cfs_rq: cfs_rq to update
- * @update_freq: should we call cfs_rq_util_change() or will the call do so
  *
  * The cfs_rq avg is the direct sum of all its entities (blocked and runnable)
  * avg. The immediate corollary is that all (fair) tasks must be attached, see
@@ -3334,7 +3358,7 @@ static inline void cfs_rq_util_change(struct cfs_rq *cfs_rq)
  * call update_tg_load_avg() when this function returns true.
  */
 static inline int
-update_cfs_rq_load_avg(u64 now, struct cfs_rq *cfs_rq, bool update_freq)
+update_cfs_rq_load_avg(u64 now, struct cfs_rq *cfs_rq)
 {
 	struct sched_avg *sa = &cfs_rq->avg;
 	int decayed, removed_load = 0, removed_util = 0;
@@ -3362,7 +3386,7 @@ update_cfs_rq_load_avg(u64 now, struct cfs_rq *cfs_rq, bool update_freq)
 	cfs_rq->load_last_update_time_copy = sa->last_update_time;
 #endif
 
-	if (update_freq && (decayed || removed_util))
+	if (decayed || removed_util)
 		cfs_rq_util_change(cfs_rq);
 
 	return decayed || removed_load;
@@ -3390,7 +3414,7 @@ static inline void update_load_avg(struct sched_entity *se, int flags)
 	if (se->avg.last_update_time && !(flags & SKIP_AGE_LOAD))
 		__update_load_avg_se(now, cpu, cfs_rq, se);
 
-	decayed  = update_cfs_rq_load_avg(now, cfs_rq, true);
+	decayed  = update_cfs_rq_load_avg(now, cfs_rq);
 	decayed |= propagate_entity_load_avg(se);
 
 	if (decayed && (flags & UPDATE_TG))
@@ -3534,7 +3558,7 @@ static int idle_balance(struct rq *this_rq, struct rq_flags *rf);
 #else /* CONFIG_SMP */
 
 static inline int
-update_cfs_rq_load_avg(u64 now, struct cfs_rq *cfs_rq, bool update_freq)
+update_cfs_rq_load_avg(u64 now, struct cfs_rq *cfs_rq)
 {
 	return 0;
 }
@@ -3544,7 +3568,7 @@ update_cfs_rq_load_avg(u64 now, struct cfs_rq *cfs_rq, bool update_freq)
 
 static inline void update_load_avg(struct sched_entity *se, int not_used1)
 {
-	cpufreq_update_util(rq_of(cfs_rq_of(se)), 0);
+	cfs_rq_util_change(cfs_rq_of(se));
 }
 
 static inline void
@@ -4875,7 +4899,7 @@ enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags)
 	 * passed.
 	 */
 	if (p->in_iowait)
-		cpufreq_update_this_cpu(rq, SCHED_CPUFREQ_IOWAIT);
+		cpufreq_update_util(rq, SCHED_CPUFREQ_IOWAIT);
 
 	for_each_sched_entity(se) {
 		if (se->on_rq)
@@ -5125,9 +5149,9 @@ static void cpu_load_update(struct rq *this_rq, unsigned long this_load,
 }
 
 /* Used instead of source_load when we know the type == 0 */
-static unsigned long weighted_cpuload(const int cpu)
+static unsigned long weighted_cpuload(struct rq *rq)
 {
-	return cfs_rq_runnable_load_avg(&cpu_rq(cpu)->cfs);
+	return cfs_rq_runnable_load_avg(&rq->cfs);
 }
 
 #ifdef CONFIG_NO_HZ_COMMON
@@ -5172,7 +5196,7 @@ static void cpu_load_update_idle(struct rq *this_rq)
 	/*
 	 * bail if there's load or we're actually up-to-date.
 	 */
-	if (weighted_cpuload(cpu_of(this_rq)))
+	if (weighted_cpuload(this_rq))
 		return;
 
 	cpu_load_update_nohz(this_rq, READ_ONCE(jiffies), 0);
@@ -5193,7 +5217,7 @@ void cpu_load_update_nohz_start(void)
 	 * concurrently we'll exit nohz. And cpu_load write can race with
 	 * cpu_load_update_idle() but both updater would be writing the same.
 	 */
-	this_rq->cpu_load[0] = weighted_cpuload(cpu_of(this_rq));
+	this_rq->cpu_load[0] = weighted_cpuload(this_rq);
 }
 
 /*
@@ -5209,7 +5233,7 @@ void cpu_load_update_nohz_stop(void)
 	if (curr_jiffies == this_rq->last_load_update_tick)
 		return;
 
-	load = weighted_cpuload(cpu_of(this_rq));
+	load = weighted_cpuload(this_rq);
 	rq_lock(this_rq, &rf);
 	update_rq_clock(this_rq);
 	cpu_load_update_nohz(this_rq, curr_jiffies, load);
@@ -5235,7 +5259,7 @@ static void cpu_load_update_periodic(struct rq *this_rq, unsigned long load)
  */
 void cpu_load_update_active(struct rq *this_rq)
 {
-	unsigned long load = weighted_cpuload(cpu_of(this_rq));
+	unsigned long load = weighted_cpuload(this_rq);
 
 	if (tick_nohz_tick_stopped())
 		cpu_load_update_nohz(this_rq, READ_ONCE(jiffies), load);
@@ -5253,7 +5277,7 @@ void cpu_load_update_active(struct rq *this_rq)
 static unsigned long source_load(int cpu, int type)
 {
 	struct rq *rq = cpu_rq(cpu);
-	unsigned long total = weighted_cpuload(cpu);
+	unsigned long total = weighted_cpuload(rq);
 
 	if (type == 0 || !sched_feat(LB_BIAS))
 		return total;
@@ -5268,7 +5292,7 @@ static unsigned long source_load(int cpu, int type)
 static unsigned long target_load(int cpu, int type)
 {
 	struct rq *rq = cpu_rq(cpu);
-	unsigned long total = weighted_cpuload(cpu);
+	unsigned long total = weighted_cpuload(rq);
 
 	if (type == 0 || !sched_feat(LB_BIAS))
 		return total;
@@ -5290,7 +5314,7 @@ 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 = weighted_cpuload(cpu);
+	unsigned long load_avg = weighted_cpuload(rq);
 
 	if (nr_running)
 		return load_avg / nr_running;
@@ -5345,20 +5369,115 @@ static int wake_wide(struct task_struct *p)
 	return 1;
 }
 
+struct llc_stats {
+	unsigned long	nr_running;
+	unsigned long	load;
+	unsigned long	capacity;
+	int		has_capacity;
+};
+
+static bool get_llc_stats(struct llc_stats *stats, int cpu)
+{
+	struct sched_domain_shared *sds = rcu_dereference(per_cpu(sd_llc_shared, cpu));
+
+	if (!sds)
+		return false;
+
+	stats->nr_running	= READ_ONCE(sds->nr_running);
+	stats->load		= READ_ONCE(sds->load);
+	stats->capacity		= READ_ONCE(sds->capacity);
+	stats->has_capacity	= stats->nr_running < per_cpu(sd_llc_size, cpu);
+
+	return true;
+}
+
+/*
+ * Can a task be moved from prev_cpu to this_cpu without causing a load
+ * imbalance that would trigger the load balancer?
+ *
+ * Since we're running on 'stale' values, we might in fact create an imbalance
+ * but recomputing these values is expensive, as that'd mean iteration 2 cache
+ * domains worth of CPUs.
+ */
+static bool
+wake_affine_llc(struct sched_domain *sd, struct task_struct *p,
+		int this_cpu, int prev_cpu, int sync)
+{
+	struct llc_stats prev_stats, this_stats;
+	s64 this_eff_load, prev_eff_load;
+	unsigned long task_load;
+
+	if (!get_llc_stats(&prev_stats, prev_cpu) ||
+	    !get_llc_stats(&this_stats, this_cpu))
+		return false;
+
+	/*
+	 * If sync wakeup then subtract the (maximum possible)
+	 * effect of the currently running task from the load
+	 * of the current LLC.
+	 */
+	if (sync) {
+		unsigned long current_load = task_h_load(current);
+
+		/* in this case load hits 0 and this LLC is considered 'idle' */
+		if (current_load > this_stats.load)
+			return true;
+
+		this_stats.load -= current_load;
+	}
+
+	/*
+	 * The has_capacity stuff is not SMT aware, but by trying to balance
+	 * the nr_running on both ends we try and fill the domain at equal
+	 * rates, thereby first consuming cores before siblings.
+	 */
+
+	/* if the old cache has capacity, stay there */
+	if (prev_stats.has_capacity && prev_stats.nr_running < this_stats.nr_running+1)
+		return false;
+
+	/* if this cache has capacity, come here */
+	if (this_stats.has_capacity && this_stats.nr_running < prev_stats.nr_running+1)
+		return true;
+
+	/*
+	 * Check to see if we can move the load without causing too much
+	 * imbalance.
+	 */
+	task_load = task_h_load(p);
+
+	this_eff_load = 100;
+	this_eff_load *= prev_stats.capacity;
+
+	prev_eff_load = 100 + (sd->imbalance_pct - 100) / 2;
+	prev_eff_load *= this_stats.capacity;
+
+	this_eff_load *= this_stats.load + task_load;
+	prev_eff_load *= prev_stats.load - task_load;
+
+	return this_eff_load <= prev_eff_load;
+}
+
 static int wake_affine(struct sched_domain *sd, struct task_struct *p,
 		       int prev_cpu, int sync)
 {
 	int this_cpu = smp_processor_id();
-	bool affine = false;
+	bool affine;
 
 	/*
-	 * Common case: CPUs are in the same socket, and select_idle_sibling()
-	 * will do its thing regardless of what we return:
+	 * Default to no affine wakeups; wake_affine() should not effect a task
+	 * placement the load-balancer feels inclined to undo. The conservative
+	 * option is therefore to not move tasks when they wake up.
 	 */
-	if (cpus_share_cache(prev_cpu, this_cpu))
-		affine = true;
-	else
-		affine = numa_wake_affine(sd, p, this_cpu, prev_cpu, sync);
+	affine = false;
+
+	/*
+	 * If the wakeup is across cache domains, try to evaluate if movement
+	 * makes sense, otherwise rely on select_idle_siblings() to do
+	 * placement inside the cache domain.
+	 */
+	if (!cpus_share_cache(prev_cpu, this_cpu))
+		affine = wake_affine_llc(sd, p, this_cpu, prev_cpu, sync);
 
 	schedstat_inc(p->se.statistics.nr_wakeups_affine_attempts);
 	if (affine) {
@@ -5550,7 +5669,7 @@ find_idlest_cpu(struct sched_group *group, struct task_struct *p, int this_cpu)
 				shallowest_idle_cpu = i;
 			}
 		} else if (shallowest_idle_cpu == -1) {
-			load = weighted_cpuload(i);
+			load = weighted_cpuload(cpu_rq(i));
 			if (load < min_load || (load == min_load && i == this_cpu)) {
 				min_load = load;
 				least_loaded_cpu = i;
@@ -6187,10 +6306,10 @@ pick_next_task_fair(struct rq *rq, struct task_struct *prev, struct rq_flags *rf
 	int new_tasks;
 
 again:
-#ifdef CONFIG_FAIR_GROUP_SCHED
 	if (!cfs_rq->nr_running)
 		goto idle;
 
+#ifdef CONFIG_FAIR_GROUP_SCHED
 	if (prev->sched_class != &fair_sched_class)
 		goto simple;
 
@@ -6220,11 +6339,17 @@ again:
 			/*
 			 * This call to check_cfs_rq_runtime() will do the
 			 * throttle and dequeue its entity in the parent(s).
-			 * Therefore the 'simple' nr_running test will indeed
+			 * Therefore the nr_running test will indeed
 			 * be correct.
 			 */
-			if (unlikely(check_cfs_rq_runtime(cfs_rq)))
+			if (unlikely(check_cfs_rq_runtime(cfs_rq))) {
+				cfs_rq = &rq->cfs;
+
+				if (!cfs_rq->nr_running)
+					goto idle;
+
 				goto simple;
+			}
 		}
 
 		se = pick_next_entity(cfs_rq, curr);
@@ -6264,12 +6389,8 @@ again:
 
 	return p;
 simple:
-	cfs_rq = &rq->cfs;
 #endif
 
-	if (!cfs_rq->nr_running)
-		goto idle;
-
 	put_prev_task(rq, prev);
 
 	do {
@@ -6917,7 +7038,7 @@ static void update_blocked_averages(int cpu)
 		if (throttled_hierarchy(cfs_rq))
 			continue;
 
-		if (update_cfs_rq_load_avg(cfs_rq_clock_task(cfs_rq), cfs_rq, true))
+		if (update_cfs_rq_load_avg(cfs_rq_clock_task(cfs_rq), cfs_rq))
 			update_tg_load_avg(cfs_rq, 0);
 
 		/* Propagate pending load changes to the parent, if any: */
@@ -6990,7 +7111,7 @@ static inline void update_blocked_averages(int cpu)
 
 	rq_lock_irqsave(rq, &rf);
 	update_rq_clock(rq);
-	update_cfs_rq_load_avg(cfs_rq_clock_task(cfs_rq), cfs_rq, true);
+	update_cfs_rq_load_avg(cfs_rq_clock_task(cfs_rq), cfs_rq);
 	rq_unlock_irqrestore(rq, &rf);
 }
 
@@ -7036,6 +7157,7 @@ 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 */
@@ -7055,6 +7177,7 @@ static inline void init_sd_lb_stats(struct sd_lb_stats *sds)
 	*sds = (struct sd_lb_stats){
 		.busiest = NULL,
 		.local = NULL,
+		.total_running = 0UL,
 		.total_load = 0UL,
 		.total_capacity = 0UL,
 		.busiest_stat = {
@@ -7363,7 +7486,7 @@ static inline void update_sg_lb_stats(struct lb_env *env,
 		sgs->nr_numa_running += rq->nr_numa_running;
 		sgs->nr_preferred_running += rq->nr_preferred_running;
 #endif
-		sgs->sum_weighted_load += weighted_cpuload(i);
+		sgs->sum_weighted_load += weighted_cpuload(rq);
 		/*
 		 * No need to call idle_cpu() if nr_running is not 0
 		 */
@@ -7490,6 +7613,7 @@ static inline enum fbq_type fbq_classify_rq(struct rq *rq)
  */
 static inline void update_sd_lb_stats(struct lb_env *env, struct sd_lb_stats *sds)
 {
+	struct sched_domain_shared *shared = env->sd->shared;
 	struct sched_domain *child = env->sd->child;
 	struct sched_group *sg = env->sd->groups;
 	struct sg_lb_stats *local = &sds->local_stat;
@@ -7546,6 +7670,7 @@ 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;
 
@@ -7561,6 +7686,21 @@ next_group:
 			env->dst_rq->rd->overload = overload;
 	}
 
+	if (!shared)
+		return;
+
+	/*
+	 * Since these are sums over groups they can contain some CPUs
+	 * multiple times for the NUMA domains.
+	 *
+	 * Currently only wake_affine_llc() and find_busiest_group()
+	 * uses these numbers, only the last is affected by this problem.
+	 *
+	 * XXX fix that.
+	 */
+	WRITE_ONCE(shared->nr_running,	sds->total_running);
+	WRITE_ONCE(shared->load,	sds->total_load);
+	WRITE_ONCE(shared->capacity,	sds->total_capacity);
 }
 
 /**
@@ -7790,6 +7930,7 @@ static struct sched_group *find_busiest_group(struct lb_env *env)
 	if (!sds.busiest || busiest->sum_nr_running == 0)
 		goto out_balanced;
 
+	/* XXX broken for overlapping NUMA groups */
 	sds.avg_load = (SCHED_CAPACITY_SCALE * sds.total_load)
 						/ sds.total_capacity;
 
@@ -7892,7 +8033,7 @@ static struct rq *find_busiest_queue(struct lb_env *env,
 
 		capacity = capacity_of(i);
 
-		wl = weighted_cpuload(i);
+		wl = weighted_cpuload(rq);
 
 		/*
 		 * When comparing with imbalance, use weighted_cpuload()