1 files changed, 28 insertions, 20 deletions

diff --git a/mm/vmstat.c b/mm/vmstat.c
index 8f62f17..3ad909d 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -167,18 +167,20 @@ static void refresh_zone_stat_thresholds(void)
 void __mod_zone_page_state(struct zone *zone, enum zone_stat_item item,
 				int delta)
 {
-	struct per_cpu_pageset *pcp = this_cpu_ptr(zone->pageset);
-
-	s8 *p = pcp->vm_stat_diff + item;
+	struct per_cpu_pageset __percpu *pcp = zone->pageset;
+	s8 __percpu *p = pcp->vm_stat_diff + item;
 	long x;
+	long t;
+
+	x = delta + __this_cpu_read(*p);
 
-	x = delta + *p;
+	t = __this_cpu_read(pcp->stat_threshold);
 
-	if (unlikely(x > pcp->stat_threshold || x < -pcp->stat_threshold)) {
+	if (unlikely(x > t || x < -t)) {
 		zone_page_state_add(x, zone, item);
 		x = 0;
 	}
-	*p = x;
+	__this_cpu_write(*p, x);
 }
 EXPORT_SYMBOL(__mod_zone_page_state);
 
@@ -221,16 +223,19 @@ EXPORT_SYMBOL(mod_zone_page_state);
  */
 void __inc_zone_state(struct zone *zone, enum zone_stat_item item)
 {
-	struct per_cpu_pageset *pcp = this_cpu_ptr(zone->pageset);
-	s8 *p = pcp->vm_stat_diff + item;
+	struct per_cpu_pageset __percpu *pcp = zone->pageset;
+	s8 __percpu *p = pcp->vm_stat_diff + item;
+	s8 v, t;
 
-	(*p)++;
+	__this_cpu_inc(*p);
 
-	if (unlikely(*p > pcp->stat_threshold)) {
-		int overstep = pcp->stat_threshold / 2;
+	v = __this_cpu_read(*p);
+	t = __this_cpu_read(pcp->stat_threshold);
+	if (unlikely(v > t)) {
+		s8 overstep = t >> 1;
 
-		zone_page_state_add(*p + overstep, zone, item);
-		*p = -overstep;
+		zone_page_state_add(v + overstep, zone, item);
+		__this_cpu_write(*p, -overstep);
 	}
 }
 
@@ -242,16 +247,19 @@ EXPORT_SYMBOL(__inc_zone_page_state);
 
 void __dec_zone_state(struct zone *zone, enum zone_stat_item item)
 {
-	struct per_cpu_pageset *pcp = this_cpu_ptr(zone->pageset);
-	s8 *p = pcp->vm_stat_diff + item;
+	struct per_cpu_pageset __percpu *pcp = zone->pageset;
+	s8 __percpu *p = pcp->vm_stat_diff + item;
+	s8 v, t;
 
-	(*p)--;
+	__this_cpu_dec(*p);
 
-	if (unlikely(*p < - pcp->stat_threshold)) {
-		int overstep = pcp->stat_threshold / 2;
+	v = __this_cpu_read(*p);
+	t = __this_cpu_read(pcp->stat_threshold);
+	if (unlikely(v < - t)) {
+		s8 overstep = t >> 1;
 
-		zone_page_state_add(*p - overstep, zone, item);
-		*p = overstep;
+		zone_page_state_add(v - overstep, zone, item);
+		__this_cpu_write(*p, overstep);
 	}
 }