1 files changed, 272 insertions, 23 deletions

diff --git a/mm/vmstat.c b/mm/vmstat.c
index 7997f529..3345d39 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -86,8 +86,10 @@ void vm_events_fold_cpu(int cpu)
  *
  * vm_stat contains the global counters
  */
-atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS] __cacheline_aligned_in_smp;
-EXPORT_SYMBOL(vm_stat);
+atomic_long_t vm_zone_stat[NR_VM_ZONE_STAT_ITEMS] __cacheline_aligned_in_smp;
+atomic_long_t vm_node_stat[NR_VM_NODE_STAT_ITEMS] __cacheline_aligned_in_smp;
+EXPORT_SYMBOL(vm_zone_stat);
+EXPORT_SYMBOL(vm_node_stat);
 
 #ifdef CONFIG_SMP
 
@@ -167,19 +169,36 @@ int calculate_normal_threshold(struct zone *zone)
  */
 void refresh_zone_stat_thresholds(void)
 {
+	struct pglist_data *pgdat;
 	struct zone *zone;
 	int cpu;
 	int threshold;
 
+	/* Zero current pgdat thresholds */
+	for_each_online_pgdat(pgdat) {
+		for_each_online_cpu(cpu) {
+			per_cpu_ptr(pgdat->per_cpu_nodestats, cpu)->stat_threshold = 0;
+		}
+	}
+
 	for_each_populated_zone(zone) {
+		struct pglist_data *pgdat = zone->zone_pgdat;
 		unsigned long max_drift, tolerate_drift;
 
 		threshold = calculate_normal_threshold(zone);
 
-		for_each_online_cpu(cpu)
+		for_each_online_cpu(cpu) {
+			int pgdat_threshold;
+
 			per_cpu_ptr(zone->pageset, cpu)->stat_threshold
 							= threshold;
 
+			/* Base nodestat threshold on the largest populated zone. */
+			pgdat_threshold = per_cpu_ptr(pgdat->per_cpu_nodestats, cpu)->stat_threshold;
+			per_cpu_ptr(pgdat->per_cpu_nodestats, cpu)->stat_threshold
+				= max(threshold, pgdat_threshold);
+		}
+
 		/*
 		 * Only set percpu_drift_mark if there is a danger that
 		 * NR_FREE_PAGES reports the low watermark is ok when in fact
@@ -238,6 +257,26 @@ void __mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
 }
 EXPORT_SYMBOL(__mod_zone_page_state);
 
+void __mod_node_page_state(struct pglist_data *pgdat, enum node_stat_item item,
+				long delta)
+{
+	struct per_cpu_nodestat __percpu *pcp = pgdat->per_cpu_nodestats;
+	s8 __percpu *p = pcp->vm_node_stat_diff + item;
+	long x;
+	long t;
+
+	x = delta + __this_cpu_read(*p);
+
+	t = __this_cpu_read(pcp->stat_threshold);
+
+	if (unlikely(x > t || x < -t)) {
+		node_page_state_add(x, pgdat, item);
+		x = 0;
+	}
+	__this_cpu_write(*p, x);
+}
+EXPORT_SYMBOL(__mod_node_page_state);
+
 /*
  * Optimized increment and decrement functions.
  *
@@ -277,12 +316,34 @@ void __inc_zone_state(struct zone *zone, enum zone_stat_item item)
 	}
 }
 
+void __inc_node_state(struct pglist_data *pgdat, enum node_stat_item item)
+{
+	struct per_cpu_nodestat __percpu *pcp = pgdat->per_cpu_nodestats;
+	s8 __percpu *p = pcp->vm_node_stat_diff + item;
+	s8 v, t;
+
+	v = __this_cpu_inc_return(*p);
+	t = __this_cpu_read(pcp->stat_threshold);
+	if (unlikely(v > t)) {
+		s8 overstep = t >> 1;
+
+		node_page_state_add(v + overstep, pgdat, item);
+		__this_cpu_write(*p, -overstep);
+	}
+}
+
 void __inc_zone_page_state(struct page *page, enum zone_stat_item item)
 {
 	__inc_zone_state(page_zone(page), item);
 }
 EXPORT_SYMBOL(__inc_zone_page_state);
 
+void __inc_node_page_state(struct page *page, enum node_stat_item item)
+{
+	__inc_node_state(page_pgdat(page), item);
+}
+EXPORT_SYMBOL(__inc_node_page_state);
+
 void __dec_zone_state(struct zone *zone, enum zone_stat_item item)
 {
 	struct per_cpu_pageset __percpu *pcp = zone->pageset;
@@ -299,12 +360,34 @@ void __dec_zone_state(struct zone *zone, enum zone_stat_item item)
 	}
 }
 
+void __dec_node_state(struct pglist_data *pgdat, enum node_stat_item item)
+{
+	struct per_cpu_nodestat __percpu *pcp = pgdat->per_cpu_nodestats;
+	s8 __percpu *p = pcp->vm_node_stat_diff + item;
+	s8 v, t;
+
+	v = __this_cpu_dec_return(*p);
+	t = __this_cpu_read(pcp->stat_threshold);
+	if (unlikely(v < - t)) {
+		s8 overstep = t >> 1;
+
+		node_page_state_add(v - overstep, pgdat, item);
+		__this_cpu_write(*p, overstep);
+	}
+}
+
 void __dec_zone_page_state(struct page *page, enum zone_stat_item item)
 {
 	__dec_zone_state(page_zone(page), item);
 }
 EXPORT_SYMBOL(__dec_zone_page_state);
 
+void __dec_node_page_state(struct page *page, enum node_stat_item item)
+{
+	__dec_node_state(page_pgdat(page), item);
+}
+EXPORT_SYMBOL(__dec_node_page_state);
+
 #ifdef CONFIG_HAVE_CMPXCHG_LOCAL
 /*
  * If we have cmpxchg_local support then we do not need to incur the overhead
@@ -318,8 +401,8 @@ EXPORT_SYMBOL(__dec_zone_page_state);
  *     1       Overstepping half of threshold
  *     -1      Overstepping minus half of threshold
 */
-static inline void mod_state(struct zone *zone, enum zone_stat_item item,
-			     long delta, int overstep_mode)
+static inline void mod_zone_state(struct zone *zone,
+       enum zone_stat_item item, long delta, int overstep_mode)
 {
 	struct per_cpu_pageset __percpu *pcp = zone->pageset;
 	s8 __percpu *p = pcp->vm_stat_diff + item;
@@ -359,26 +442,88 @@ static inline void mod_state(struct zone *zone, enum zone_stat_item item,
 void mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
 			 long delta)
 {
-	mod_state(zone, item, delta, 0);
+	mod_zone_state(zone, item, delta, 0);
 }
 EXPORT_SYMBOL(mod_zone_page_state);
 
 void inc_zone_state(struct zone *zone, enum zone_stat_item item)
 {
-	mod_state(zone, item, 1, 1);
+	mod_zone_state(zone, item, 1, 1);
 }
 
 void inc_zone_page_state(struct page *page, enum zone_stat_item item)
 {
-	mod_state(page_zone(page), item, 1, 1);
+	mod_zone_state(page_zone(page), item, 1, 1);
 }
 EXPORT_SYMBOL(inc_zone_page_state);
 
 void dec_zone_page_state(struct page *page, enum zone_stat_item item)
 {
-	mod_state(page_zone(page), item, -1, -1);
+	mod_zone_state(page_zone(page), item, -1, -1);
 }
 EXPORT_SYMBOL(dec_zone_page_state);
+
+static inline void mod_node_state(struct pglist_data *pgdat,
+       enum node_stat_item item, int delta, int overstep_mode)
+{
+	struct per_cpu_nodestat __percpu *pcp = pgdat->per_cpu_nodestats;
+	s8 __percpu *p = pcp->vm_node_stat_diff + item;
+	long o, n, t, z;
+
+	do {
+		z = 0;  /* overflow to node counters */
+
+		/*
+		 * The fetching of the stat_threshold is racy. We may apply
+		 * a counter threshold to the wrong the cpu if we get
+		 * rescheduled while executing here. However, the next
+		 * counter update will apply the threshold again and
+		 * therefore bring the counter under the threshold again.
+		 *
+		 * Most of the time the thresholds are the same anyways
+		 * for all cpus in a node.
+		 */
+		t = this_cpu_read(pcp->stat_threshold);
+
+		o = this_cpu_read(*p);
+		n = delta + o;
+
+		if (n > t || n < -t) {
+			int os = overstep_mode * (t >> 1) ;
+
+			/* Overflow must be added to node counters */
+			z = n + os;
+			n = -os;
+		}
+	} while (this_cpu_cmpxchg(*p, o, n) != o);
+
+	if (z)
+		node_page_state_add(z, pgdat, item);
+}
+
+void mod_node_page_state(struct pglist_data *pgdat, enum node_stat_item item,
+					long delta)
+{
+	mod_node_state(pgdat, item, delta, 0);
+}
+EXPORT_SYMBOL(mod_node_page_state);
+
+void inc_node_state(struct pglist_data *pgdat, enum node_stat_item item)
+{
+	mod_node_state(pgdat, item, 1, 1);
+}
+
+void inc_node_page_state(struct page *page, enum node_stat_item item)
+{
+	mod_node_state(page_pgdat(page), item, 1, 1);
+}
+EXPORT_SYMBOL(inc_node_page_state);
+
+void dec_node_page_state(struct page *page, enum node_stat_item item)
+{
+	mod_node_state(page_pgdat(page), item, -1, -1);
+}
+EXPORT_SYMBOL(dec_node_page_state);
 #else
 /*
  * Use interrupt disable to serialize counter updates
@@ -424,21 +569,69 @@ void dec_zone_page_state(struct page *page, enum zone_stat_item item)
 	local_irq_restore(flags);
 }
 EXPORT_SYMBOL(dec_zone_page_state);
-#endif
 
+void inc_node_state(struct pglist_data *pgdat, enum node_stat_item item)
+{
+	unsigned long flags;
+
+	local_irq_save(flags);
+	__inc_node_state(pgdat, item);
+	local_irq_restore(flags);
+}
+EXPORT_SYMBOL(inc_node_state);
+
+void mod_node_page_state(struct pglist_data *pgdat, enum node_stat_item item,
+					long delta)
+{
+	unsigned long flags;
+
+	local_irq_save(flags);
+	__mod_node_page_state(pgdat, item, delta);
+	local_irq_restore(flags);
+}
+EXPORT_SYMBOL(mod_node_page_state);
+
+void inc_node_page_state(struct page *page, enum node_stat_item item)
+{
+	unsigned long flags;
+	struct pglist_data *pgdat;
+
+	pgdat = page_pgdat(page);
+	local_irq_save(flags);
+	__inc_node_state(pgdat, item);
+	local_irq_restore(flags);
+}
+EXPORT_SYMBOL(inc_node_page_state);
+
+void dec_node_page_state(struct page *page, enum node_stat_item item)
+{
+	unsigned long flags;
+
+	local_irq_save(flags);
+	__dec_node_page_state(page, item);
+	local_irq_restore(flags);
+}
+EXPORT_SYMBOL(dec_node_page_state);
+#endif
 
 /*
  * Fold a differential into the global counters.
  * Returns the number of counters updated.
  */
-static int fold_diff(int *diff)
+static int fold_diff(int *zone_diff, int *node_diff)
 {
 	int i;
 	int changes = 0;
 
 	for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++)
-		if (diff[i]) {
-			atomic_long_add(diff[i], &vm_stat[i]);
+		if (zone_diff[i]) {
+			atomic_long_add(zone_diff[i], &vm_zone_stat[i]);
+			changes++;
+	}
+
+	for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++)
+		if (node_diff[i]) {
+			atomic_long_add(node_diff[i], &vm_node_stat[i]);
 			changes++;
 	}
 	return changes;
@@ -462,9 +655,11 @@ static int fold_diff(int *diff)
  */
 static int refresh_cpu_vm_stats(bool do_pagesets)
 {
+	struct pglist_data *pgdat;
 	struct zone *zone;
 	int i;
-	int global_diff[NR_VM_ZONE_STAT_ITEMS] = { 0, };
+	int global_zone_diff[NR_VM_ZONE_STAT_ITEMS] = { 0, };
+	int global_node_diff[NR_VM_NODE_STAT_ITEMS] = { 0, };
 	int changes = 0;
 
 	for_each_populated_zone(zone) {
@@ -477,7 +672,7 @@ static int refresh_cpu_vm_stats(bool do_pagesets)
 			if (v) {
 
 				atomic_long_add(v, &zone->vm_stat[i]);
-				global_diff[i] += v;
+				global_zone_diff[i] += v;
 #ifdef CONFIG_NUMA
 				/* 3 seconds idle till flush */
 				__this_cpu_write(p->expire, 3);
@@ -516,7 +711,22 @@ static int refresh_cpu_vm_stats(bool do_pagesets)
 		}
 #endif
 	}
-	changes += fold_diff(global_diff);
+
+	for_each_online_pgdat(pgdat) {
+		struct per_cpu_nodestat __percpu *p = pgdat->per_cpu_nodestats;
+
+		for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++) {
+			int v;
+
+			v = this_cpu_xchg(p->vm_node_stat_diff[i], 0);
+			if (v) {
+				atomic_long_add(v, &pgdat->vm_stat[i]);
+				global_node_diff[i] += v;
+			}
+		}
+	}
+
+	changes += fold_diff(global_zone_diff, global_node_diff);
 	return changes;
 }
 
@@ -527,9 +737,11 @@ static int refresh_cpu_vm_stats(bool do_pagesets)
  */
 void cpu_vm_stats_fold(int cpu)
 {
+	struct pglist_data *pgdat;
 	struct zone *zone;
 	int i;
-	int global_diff[NR_VM_ZONE_STAT_ITEMS] = { 0, };
+	int global_zone_diff[NR_VM_ZONE_STAT_ITEMS] = { 0, };
+	int global_node_diff[NR_VM_NODE_STAT_ITEMS] = { 0, };
 
 	for_each_populated_zone(zone) {
 		struct per_cpu_pageset *p;
@@ -543,11 +755,27 @@ void cpu_vm_stats_fold(int cpu)
 				v = p->vm_stat_diff[i];
 				p->vm_stat_diff[i] = 0;
 				atomic_long_add(v, &zone->vm_stat[i]);
-				global_diff[i] += v;
+				global_zone_diff[i] += v;
 			}
 	}
 
-	fold_diff(global_diff);
+	for_each_online_pgdat(pgdat) {
+		struct per_cpu_nodestat *p;
+
+		p = per_cpu_ptr(pgdat->per_cpu_nodestats, cpu);
+
+		for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++)
+			if (p->vm_node_stat_diff[i]) {
+				int v;
+
+				v = p->vm_node_stat_diff[i];
+				p->vm_node_stat_diff[i] = 0;
+				atomic_long_add(v, &pgdat->vm_stat[i]);
+				global_node_diff[i] += v;
+			}
+	}
+
+	fold_diff(global_zone_diff, global_node_diff);
 }
 
 /*
@@ -563,16 +791,19 @@ void drain_zonestat(struct zone *zone, struct per_cpu_pageset *pset)
 			int v = pset->vm_stat_diff[i];
 			pset->vm_stat_diff[i] = 0;
 			atomic_long_add(v, &zone->vm_stat[i]);
-			atomic_long_add(v, &vm_stat[i]);
+			atomic_long_add(v, &vm_zone_stat[i]);
 		}
 }
 #endif
 
 #ifdef CONFIG_NUMA
 /*
- * Determine the per node value of a stat item.
+ * Determine the per node value of a stat item. This function
+ * is called frequently in a NUMA machine, so try to be as
+ * frugal as possible.
  */
-unsigned long node_page_state(int node, enum zone_stat_item item)
+unsigned long sum_zone_node_page_state(int node,
+				 enum zone_stat_item item)
 {
 	struct zone *zones = NODE_DATA(node)->node_zones;
 	int i;
@@ -584,6 +815,19 @@ unsigned long node_page_state(int node, enum zone_stat_item item)
 	return count;
 }
 
+/*
+ * Determine the per node value of a stat item.
+ */
+unsigned long node_page_state(struct pglist_data *pgdat,
+				enum node_stat_item item)
+{
+	long x = atomic_long_read(&pgdat->vm_stat[item]);
+#ifdef CONFIG_SMP
+	if (x < 0)
+		x = 0;
+#endif
+	return x;
+}
 #endif
 
 #ifdef CONFIG_COMPACTION
@@ -1287,6 +1531,7 @@ static void *vmstat_start(struct seq_file *m, loff_t *pos)
 	if (*pos >= ARRAY_SIZE(vmstat_text))
 		return NULL;
 	stat_items_size = NR_VM_ZONE_STAT_ITEMS * sizeof(unsigned long) +
+			  NR_VM_NODE_STAT_ITEMS * sizeof(unsigned long) +
 			  NR_VM_WRITEBACK_STAT_ITEMS * sizeof(unsigned long);
 
 #ifdef CONFIG_VM_EVENT_COUNTERS
@@ -1301,6 +1546,10 @@ static void *vmstat_start(struct seq_file *m, loff_t *pos)
 		v[i] = global_page_state(i);
 	v += NR_VM_ZONE_STAT_ITEMS;
 
+	for (i = 0; i < NR_VM_NODE_STAT_ITEMS; i++)
+		v[i] = global_node_page_state(i);
+	v += NR_VM_NODE_STAT_ITEMS;
+
 	global_dirty_limits(v + NR_DIRTY_BG_THRESHOLD,
 			    v + NR_DIRTY_THRESHOLD);
 	v += NR_VM_WRITEBACK_STAT_ITEMS;
@@ -1390,7 +1639,7 @@ int vmstat_refresh(struct ctl_table *table, int write,
 	if (err)
 		return err;
 	for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) {
-		val = atomic_long_read(&vm_stat[i]);
+		val = atomic_long_read(&vm_zone_stat[i]);
 		if (val < 0) {
 			switch (i) {
 			case NR_ALLOC_BATCH: