1 files changed, 132 insertions, 131 deletions

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index e8b652ebe027..b24b6cfde9aa 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -178,59 +178,61 @@ void sched_init_granularity(void)
 	update_sysctl();
 }
 
-#if BITS_PER_LONG == 32
-# define WMULT_CONST	(~0UL)
-#else
-# define WMULT_CONST	(1UL << 32)
-#endif
-
+#define WMULT_CONST	(~0U)
 #define WMULT_SHIFT	32
 
-/*
- * Shift right and round:
- */
-#define SRR(x, y) (((x) + (1UL << ((y) - 1))) >> (y))
+static void __update_inv_weight(struct load_weight *lw)
+{
+	unsigned long w;
+
+	if (likely(lw->inv_weight))
+		return;
+
+	w = scale_load_down(lw->weight);
+
+	if (BITS_PER_LONG > 32 && unlikely(w >= WMULT_CONST))
+		lw->inv_weight = 1;
+	else if (unlikely(!w))
+		lw->inv_weight = WMULT_CONST;
+	else
+		lw->inv_weight = WMULT_CONST / w;
+}
 
 /*
- * delta *= weight / lw
+ * delta_exec * weight / lw.weight
+ *   OR
+ * (delta_exec * (weight * lw->inv_weight)) >> WMULT_SHIFT
+ *
+ * Either weight := NICE_0_LOAD and lw \e prio_to_wmult[], in which case
+ * we're guaranteed shift stays positive because inv_weight is guaranteed to
+ * fit 32 bits, and NICE_0_LOAD gives another 10 bits; therefore shift >= 22.
+ *
+ * Or, weight =< lw.weight (because lw.weight is the runqueue weight), thus
+ * weight/lw.weight <= 1, and therefore our shift will also be positive.
  */
-static unsigned long
-calc_delta_mine(unsigned long delta_exec, unsigned long weight,
-		struct load_weight *lw)
+static u64 __calc_delta(u64 delta_exec, unsigned long weight, struct load_weight *lw)
 {
-	u64 tmp;
+	u64 fact = scale_load_down(weight);
+	int shift = WMULT_SHIFT;
 
-	/*
-	 * weight can be less than 2^SCHED_LOAD_RESOLUTION for task group sched
-	 * entities since MIN_SHARES = 2. Treat weight as 1 if less than
-	 * 2^SCHED_LOAD_RESOLUTION.
-	 */
-	if (likely(weight > (1UL << SCHED_LOAD_RESOLUTION)))
-		tmp = (u64)delta_exec * scale_load_down(weight);
-	else
-		tmp = (u64)delta_exec;
-
-	if (!lw->inv_weight) {
-		unsigned long w = scale_load_down(lw->weight);
+	__update_inv_weight(lw);
 
-		if (BITS_PER_LONG > 32 && unlikely(w >= WMULT_CONST))
-			lw->inv_weight = 1;
-		else if (unlikely(!w))
-			lw->inv_weight = WMULT_CONST;
-		else
-			lw->inv_weight = WMULT_CONST / w;
+	if (unlikely(fact >> 32)) {
+		while (fact >> 32) {
+			fact >>= 1;
+			shift--;
+		}
 	}
 
-	/*
-	 * Check whether we'd overflow the 64-bit multiplication:
-	 */
-	if (unlikely(tmp > WMULT_CONST))
-		tmp = SRR(SRR(tmp, WMULT_SHIFT/2) * lw->inv_weight,
-			WMULT_SHIFT/2);
-	else
-		tmp = SRR(tmp * lw->inv_weight, WMULT_SHIFT);
+	/* hint to use a 32x32->64 mul */
+	fact = (u64)(u32)fact * lw->inv_weight;
+
+	while (fact >> 32) {
+		fact >>= 1;
+		shift--;
+	}
 
-	return (unsigned long)min(tmp, (u64)(unsigned long)LONG_MAX);
+	return mul_u64_u32_shr(delta_exec, fact, shift);
 }
 
 
@@ -443,7 +445,7 @@ find_matching_se(struct sched_entity **se, struct sched_entity **pse)
 #endif	/* CONFIG_FAIR_GROUP_SCHED */
 
 static __always_inline
-void account_cfs_rq_runtime(struct cfs_rq *cfs_rq, unsigned long delta_exec);
+void account_cfs_rq_runtime(struct cfs_rq *cfs_rq, u64 delta_exec);
 
 /**************************************************************
  * Scheduling class tree data structure manipulation methods:
@@ -612,11 +614,10 @@ int sched_proc_update_handler(struct ctl_table *table, int write,
 /*
  * delta /= w
  */
-static inline unsigned long
-calc_delta_fair(unsigned long delta, struct sched_entity *se)
+static inline u64 calc_delta_fair(u64 delta, struct sched_entity *se)
 {
 	if (unlikely(se->load.weight != NICE_0_LOAD))
-		delta = calc_delta_mine(delta, NICE_0_LOAD, &se->load);
+		delta = __calc_delta(delta, NICE_0_LOAD, &se->load);
 
 	return delta;
 }
@@ -665,7 +666,7 @@ static u64 sched_slice(struct cfs_rq *cfs_rq, struct sched_entity *se)
 			update_load_add(&lw, se->load.weight);
 			load = &lw;
 		}
-		slice = calc_delta_mine(slice, se->load.weight, load);
+		slice = __calc_delta(slice, se->load.weight, load);
 	}
 	return slice;
 }
@@ -703,47 +704,32 @@ void init_task_runnable_average(struct task_struct *p)
 #endif
 
 /*
- * Update the current task's runtime statistics. Skip current tasks that
- * are not in our scheduling class.
+ * Update the current task's runtime statistics.
  */
-static inline void
-__update_curr(struct cfs_rq *cfs_rq, struct sched_entity *curr,
-	      unsigned long delta_exec)
-{
-	unsigned long delta_exec_weighted;
-
-	schedstat_set(curr->statistics.exec_max,
-		      max((u64)delta_exec, curr->statistics.exec_max));
-
-	curr->sum_exec_runtime += delta_exec;
-	schedstat_add(cfs_rq, exec_clock, delta_exec);
-	delta_exec_weighted = calc_delta_fair(delta_exec, curr);
-
-	curr->vruntime += delta_exec_weighted;
-	update_min_vruntime(cfs_rq);
-}
-
 static void update_curr(struct cfs_rq *cfs_rq)
 {
 	struct sched_entity *curr = cfs_rq->curr;
 	u64 now = rq_clock_task(rq_of(cfs_rq));
-	unsigned long delta_exec;
+	u64 delta_exec;
 
 	if (unlikely(!curr))
 		return;
 
-	/*
-	 * Get the amount of time the current task was running
-	 * since the last time we changed load (this cannot
-	 * overflow on 32 bits):
-	 */
-	delta_exec = (unsigned long)(now - curr->exec_start);
-	if (!delta_exec)
+	delta_exec = now - curr->exec_start;
+	if (unlikely((s64)delta_exec <= 0))
 		return;
 
-	__update_curr(cfs_rq, curr, delta_exec);
 	curr->exec_start = now;
 
+	schedstat_set(curr->statistics.exec_max,
+		      max(delta_exec, curr->statistics.exec_max));
+
+	curr->sum_exec_runtime += delta_exec;
+	schedstat_add(cfs_rq, exec_clock, delta_exec);
+
+	curr->vruntime += calc_delta_fair(delta_exec, curr);
+	update_min_vruntime(cfs_rq);
+
 	if (entity_is_task(curr)) {
 		struct task_struct *curtask = task_of(curr);
 
@@ -886,15 +872,6 @@ static unsigned int task_scan_max(struct task_struct *p)
 	return max(smin, smax);
 }
 
-/*
- * Once a preferred node is selected the scheduler balancer will prefer moving
- * a task to that node for sysctl_numa_balancing_settle_count number of PTE
- * scans. This will give the process the chance to accumulate more faults on
- * the preferred node but still allow the scheduler to move the task again if
- * the nodes CPUs are overloaded.
- */
-unsigned int sysctl_numa_balancing_settle_count __read_mostly = 4;
-
 static void account_numa_enqueue(struct rq *rq, struct task_struct *p)
 {
 	rq->nr_numa_running += (p->numa_preferred_nid != -1);
@@ -944,7 +921,8 @@ static inline unsigned long group_faults(struct task_struct *p, int nid)
 	if (!p->numa_group)
 		return 0;
 
-	return p->numa_group->faults[2*nid] + p->numa_group->faults[2*nid+1];
+	return p->numa_group->faults[task_faults_idx(nid, 0)] +
+		p->numa_group->faults[task_faults_idx(nid, 1)];
 }
 
 /*
@@ -1037,7 +1015,7 @@ struct task_numa_env {
 
 	struct numa_stats src_stats, dst_stats;
 
-	int imbalance_pct, idx;
+	int imbalance_pct;
 
 	struct task_struct *best_task;
 	long best_imp;
@@ -1225,7 +1203,7 @@ static int task_numa_migrate(struct task_struct *p)
 	 * elsewhere, so there is no point in (re)trying.
 	 */
 	if (unlikely(!sd)) {
-		p->numa_preferred_nid = cpu_to_node(task_cpu(p));
+		p->numa_preferred_nid = task_node(p);
 		return -EINVAL;
 	}
 
@@ -1292,7 +1270,7 @@ static void numa_migrate_preferred(struct task_struct *p)
 	p->numa_migrate_retry = jiffies + HZ;
 
 	/* Success if task is already running on preferred CPU */
-	if (cpu_to_node(task_cpu(p)) == p->numa_preferred_nid)
+	if (task_node(p) == p->numa_preferred_nid)
 		return;
 
 	/* Otherwise, try migrate to a CPU on the preferred node */
@@ -1364,7 +1342,6 @@ static void update_task_scan_period(struct task_struct *p,
 		 * scanning faster if shared accesses dominate as it may
 		 * simply bounce migrations uselessly
 		 */
-		period_slot = DIV_ROUND_UP(diff, NUMA_PERIOD_SLOTS);
 		ratio = DIV_ROUND_UP(private * NUMA_PERIOD_SLOTS, (private + shared));
 		diff = (diff * ratio) / NUMA_PERIOD_SLOTS;
 	}
@@ -1752,6 +1729,13 @@ void task_numa_work(struct callback_head *work)
 		    (vma->vm_file && (vma->vm_flags & (VM_READ|VM_WRITE)) == (VM_READ)))
 			continue;
 
+		/*
+		 * Skip inaccessible VMAs to avoid any confusion between
+		 * PROT_NONE and NUMA hinting ptes
+		 */
+		if (!(vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE)))
+			continue;
+
 		do {
 			start = max(start, vma->vm_start);
 			end = ALIGN(start + (pages << PAGE_SHIFT), HPAGE_SIZE);
@@ -3015,8 +2999,7 @@ static void expire_cfs_rq_runtime(struct cfs_rq *cfs_rq)
 	}
 }
 
-static void __account_cfs_rq_runtime(struct cfs_rq *cfs_rq,
-				     unsigned long delta_exec)
+static void __account_cfs_rq_runtime(struct cfs_rq *cfs_rq, u64 delta_exec)
 {
 	/* dock delta_exec before expiring quota (as it could span periods) */
 	cfs_rq->runtime_remaining -= delta_exec;
@@ -3034,7 +3017,7 @@ static void __account_cfs_rq_runtime(struct cfs_rq *cfs_rq,
 }
 
 static __always_inline
-void account_cfs_rq_runtime(struct cfs_rq *cfs_rq, unsigned long delta_exec)
+void account_cfs_rq_runtime(struct cfs_rq *cfs_rq, u64 delta_exec)
 {
 	if (!cfs_bandwidth_used() || !cfs_rq->runtime_enabled)
 		return;
@@ -3574,8 +3557,7 @@ static inline u64 cfs_rq_clock_task(struct cfs_rq *cfs_rq)
 	return rq_clock_task(rq_of(cfs_rq));
 }
 
-static void account_cfs_rq_runtime(struct cfs_rq *cfs_rq,
-				     unsigned long delta_exec) {}
+static void account_cfs_rq_runtime(struct cfs_rq *cfs_rq, u64 delta_exec) {}
 static void check_cfs_rq_runtime(struct cfs_rq *cfs_rq) {}
 static void check_enqueue_throttle(struct cfs_rq *cfs_rq) {}
 static __always_inline void return_cfs_rq_runtime(struct cfs_rq *cfs_rq) {}
@@ -3932,7 +3914,7 @@ static long effective_load(struct task_group *tg, int cpu, long wl, long wg)
 {
 	struct sched_entity *se = tg->se[cpu];
 
-	if (!tg->parent || !wl)	/* the trivial, non-cgroup case */
+	if (!tg->parent)	/* the trivial, non-cgroup case */
 		return wl;
 
 	for_each_sched_entity(se) {
@@ -4110,12 +4092,16 @@ static int wake_affine(struct sched_domain *sd, struct task_struct *p, int sync)
  */
 static struct sched_group *
 find_idlest_group(struct sched_domain *sd, struct task_struct *p,
-		  int this_cpu, int load_idx)
+		  int this_cpu, int sd_flag)
 {
 	struct sched_group *idlest = NULL, *group = sd->groups;
 	unsigned long min_load = ULONG_MAX, this_load = 0;
+	int load_idx = sd->forkexec_idx;
 	int imbalance = 100 + (sd->imbalance_pct-100)/2;
 
+	if (sd_flag & SD_BALANCE_WAKE)
+		load_idx = sd->wake_idx;
+
 	do {
 		unsigned long load, avg_load;
 		int local_group;
@@ -4283,7 +4269,6 @@ select_task_rq_fair(struct task_struct *p, int prev_cpu, int sd_flag, int wake_f
 	}
 
 	while (sd) {
-		int load_idx = sd->forkexec_idx;
 		struct sched_group *group;
 		int weight;
 
@@ -4292,10 +4277,7 @@ select_task_rq_fair(struct task_struct *p, int prev_cpu, int sd_flag, int wake_f
 			continue;
 		}
 
-		if (sd_flag & SD_BALANCE_WAKE)
-			load_idx = sd->wake_idx;
-
-		group = find_idlest_group(sd, p, cpu, load_idx);
+		group = find_idlest_group(sd, p, cpu, sd_flag);
 		if (!group) {
 			sd = sd->child;
 			continue;
@@ -5379,10 +5361,31 @@ void update_group_power(struct sched_domain *sd, int cpu)
 		 */
 
 		for_each_cpu(cpu, sched_group_cpus(sdg)) {
-			struct sched_group *sg = cpu_rq(cpu)->sd->groups;
+			struct sched_group_power *sgp;
+			struct rq *rq = cpu_rq(cpu);
+
+			/*
+			 * build_sched_domains() -> init_sched_groups_power()
+			 * gets here before we've attached the domains to the
+			 * runqueues.
+			 *
+			 * Use power_of(), which is set irrespective of domains
+			 * in update_cpu_power().
+			 *
+			 * This avoids power/power_orig from being 0 and
+			 * causing divide-by-zero issues on boot.
+			 *
+			 * Runtime updates will correct power_orig.
+			 */
+			if (unlikely(!rq->sd)) {
+				power_orig += power_of(cpu);
+				power += power_of(cpu);
+				continue;
+			}
 
-			power_orig += sg->sgp->power_orig;
-			power += sg->sgp->power;
+			sgp = rq->sd->groups->sgp;
+			power_orig += sgp->power_orig;
+			power += sgp->power;
 		}
 	} else  {
 		/*
@@ -5500,7 +5503,6 @@ static inline void update_sg_lb_stats(struct lb_env *env,
 			struct sched_group *group, int load_idx,
 			int local_group, struct sg_lb_stats *sgs)
 {
-	unsigned long nr_running;
 	unsigned long load;
 	int i;
 
@@ -5509,8 +5511,6 @@ static inline void update_sg_lb_stats(struct lb_env *env,
 	for_each_cpu_and(i, sched_group_cpus(group), env->cpus) {
 		struct rq *rq = cpu_rq(i);
 
-		nr_running = rq->nr_running;
-
 		/* Bias balancing toward cpus of our domain */
 		if (local_group)
 			load = target_load(i, load_idx);
@@ -5518,7 +5518,7 @@ static inline void update_sg_lb_stats(struct lb_env *env,
 			load = source_load(i, load_idx);
 
 		sgs->group_load += load;
-		sgs->sum_nr_running += nr_running;
+		sgs->sum_nr_running += rq->nr_running;
 #ifdef CONFIG_NUMA_BALANCING
 		sgs->nr_numa_running += rq->nr_numa_running;
 		sgs->nr_preferred_running += rq->nr_preferred_running;
@@ -6509,7 +6509,7 @@ static struct {
 	unsigned long next_balance;     /* in jiffy units */
 } nohz ____cacheline_aligned;
 
-static inline int find_new_ilb(int call_cpu)
+static inline int find_new_ilb(void)
 {
 	int ilb = cpumask_first(nohz.idle_cpus_mask);
 
@@ -6524,13 +6524,13 @@ static inline int find_new_ilb(int call_cpu)
  * nohz_load_balancer CPU (if there is one) otherwise fallback to any idle
  * CPU (if there is one).
  */
-static void nohz_balancer_kick(int cpu)
+static void nohz_balancer_kick(void)
 {
 	int ilb_cpu;
 
 	nohz.next_balance++;
 
-	ilb_cpu = find_new_ilb(cpu);
+	ilb_cpu = find_new_ilb();
 
 	if (ilb_cpu >= nr_cpu_ids)
 		return;
@@ -6640,10 +6640,10 @@ void update_max_interval(void)
  *
  * Balancing parameters are set up in init_sched_domains.
  */
-static void rebalance_domains(int cpu, enum cpu_idle_type idle)
+static void rebalance_domains(struct rq *rq, enum cpu_idle_type idle)
 {
 	int continue_balancing = 1;
-	struct rq *rq = cpu_rq(cpu);
+	int cpu = rq->cpu;
 	unsigned long interval;
 	struct sched_domain *sd;
 	/* Earliest time when we have to do rebalance again */
@@ -6740,9 +6740,9 @@ out:
  * In CONFIG_NO_HZ_COMMON case, the idle balance kickee will do the
  * rebalancing for all the cpus for whom scheduler ticks are stopped.
  */
-static void nohz_idle_balance(int this_cpu, enum cpu_idle_type idle)
+static void nohz_idle_balance(struct rq *this_rq, enum cpu_idle_type idle)
 {
-	struct rq *this_rq = cpu_rq(this_cpu);
+	int this_cpu = this_rq->cpu;
 	struct rq *rq;
 	int balance_cpu;
 
@@ -6769,7 +6769,7 @@ static void nohz_idle_balance(int this_cpu, enum cpu_idle_type idle)
 		update_idle_cpu_load(rq);
 		raw_spin_unlock_irq(&rq->lock);
 
-		rebalance_domains(balance_cpu, CPU_IDLE);
+		rebalance_domains(rq, CPU_IDLE);
 
 		if (time_after(this_rq->next_balance, rq->next_balance))
 			this_rq->next_balance = rq->next_balance;
@@ -6788,14 +6788,14 @@ end:
  *   - For SD_ASYM_PACKING, if the lower numbered cpu's in the scheduler
  *     domain span are idle.
  */
-static inline int nohz_kick_needed(struct rq *rq, int cpu)
+static inline int nohz_kick_needed(struct rq *rq)
 {
 	unsigned long now = jiffies;
 	struct sched_domain *sd;
 	struct sched_group_power *sgp;
-	int nr_busy;
+	int nr_busy, cpu = rq->cpu;
 
-	if (unlikely(idle_cpu(cpu)))
+	if (unlikely(rq->idle_balance))
 		return 0;
 
        /*
@@ -6844,7 +6844,7 @@ need_kick:
 	return 1;
 }
 #else
-static void nohz_idle_balance(int this_cpu, enum cpu_idle_type idle) { }
+static void nohz_idle_balance(struct rq *this_rq, enum cpu_idle_type idle) { }
 #endif
 
 /*
@@ -6853,38 +6853,39 @@ static void nohz_idle_balance(int this_cpu, enum cpu_idle_type idle) { }
  */
 static void run_rebalance_domains(struct softirq_action *h)
 {
-	int this_cpu = smp_processor_id();
-	struct rq *this_rq = cpu_rq(this_cpu);
+	struct rq *this_rq = this_rq();
 	enum cpu_idle_type idle = this_rq->idle_balance ?
 						CPU_IDLE : CPU_NOT_IDLE;
 
-	rebalance_domains(this_cpu, idle);
+	rebalance_domains(this_rq, idle);
 
 	/*
 	 * If this cpu has a pending nohz_balance_kick, then do the
 	 * balancing on behalf of the other idle cpus whose ticks are
 	 * stopped.
 	 */
-	nohz_idle_balance(this_cpu, idle);
+	nohz_idle_balance(this_rq, idle);
 }
 
-static inline int on_null_domain(int cpu)
+static inline int on_null_domain(struct rq *rq)
 {
-	return !rcu_dereference_sched(cpu_rq(cpu)->sd);
+	return !rcu_dereference_sched(rq->sd);
 }
 
 /*
  * Trigger the SCHED_SOFTIRQ if it is time to do periodic load balancing.
  */
-void trigger_load_balance(struct rq *rq, int cpu)
+void trigger_load_balance(struct rq *rq)
 {
 	/* Don't need to rebalance while attached to NULL domain */
-	if (time_after_eq(jiffies, rq->next_balance) &&
-	    likely(!on_null_domain(cpu)))
+	if (unlikely(on_null_domain(rq)))
+		return;
+
+	if (time_after_eq(jiffies, rq->next_balance))
 		raise_softirq(SCHED_SOFTIRQ);
 #ifdef CONFIG_NO_HZ_COMMON
-	if (nohz_kick_needed(rq, cpu) && likely(!on_null_domain(cpu)))
-		nohz_balancer_kick(cpu);
+	if (nohz_kick_needed(rq))
+		nohz_balancer_kick();
 #endif
 }