X-Git-Url: http://pileus.org/git/?a=blobdiff_plain;f=mm%2Fmemcontrol.c;h=6aff93c98acaf6020eabd37f2e9b49a04135f187;hb=3542b854bc26e5f8e42e0eab4d7f7453b74a362d;hp=ce7b35d024e9e8701c44f1d6f22a44fc62084fa4;hpb=9b272977e3b99a8699361d214b51f98c8a9e0e7b;p=~andy%2Flinux

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index ce7b35d024e..6aff93c98ac 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -33,6 +33,7 @@
 #include <linux/bit_spinlock.h>
 #include <linux/rcupdate.h>
 #include <linux/limits.h>
+#include <linux/export.h>
 #include <linux/mutex.h>
 #include <linux/rbtree.h>
 #include <linux/slab.h>
@@ -686,8 +687,8 @@ static bool __memcg_event_check(struct mem_cgroup *memcg, int target)
 {
 	unsigned long val, next;
 
-	val = this_cpu_read(memcg->stat->events[MEM_CGROUP_EVENTS_COUNT]);
-	next = this_cpu_read(memcg->stat->targets[target]);
+	val = __this_cpu_read(memcg->stat->events[MEM_CGROUP_EVENTS_COUNT]);
+	next = __this_cpu_read(memcg->stat->targets[target]);
 	/* from time_after() in jiffies.h */
 	return ((long)next - (long)val < 0);
 }
@@ -696,7 +697,7 @@ static void __mem_cgroup_target_update(struct mem_cgroup *memcg, int target)
 {
 	unsigned long val, next;
 
-	val = this_cpu_read(memcg->stat->events[MEM_CGROUP_EVENTS_COUNT]);
+	val = __this_cpu_read(memcg->stat->events[MEM_CGROUP_EVENTS_COUNT]);
 
 	switch (target) {
 	case MEM_CGROUP_TARGET_THRESH:
@@ -712,7 +713,7 @@ static void __mem_cgroup_target_update(struct mem_cgroup *memcg, int target)
 		return;
 	}
 
-	this_cpu_write(memcg->stat->targets[target], next);
+	__this_cpu_write(memcg->stat->targets[target], next);
 }
 
 /*
@@ -721,6 +722,7 @@ static void __mem_cgroup_target_update(struct mem_cgroup *memcg, int target)
  */
 static void memcg_check_events(struct mem_cgroup *memcg, struct page *page)
 {
+	preempt_disable();
 	/* threshold event is triggered in finer grain than soft limit */
 	if (unlikely(__memcg_event_check(memcg, MEM_CGROUP_TARGET_THRESH))) {
 		mem_cgroup_threshold(memcg);
@@ -740,6 +742,7 @@ static void memcg_check_events(struct mem_cgroup *memcg, struct page *page)
 		}
 #endif
 	}
+	preempt_enable();
 }
 
 static struct mem_cgroup *mem_cgroup_from_cont(struct cgroup *cont)
@@ -993,6 +996,16 @@ void mem_cgroup_add_lru_list(struct page *page, enum lru_list lru)
 		return;
 	pc = lookup_page_cgroup(page);
 	VM_BUG_ON(PageCgroupAcctLRU(pc));
+	/*
+	 * putback:				charge:
+	 * SetPageLRU				SetPageCgroupUsed
+	 * smp_mb				smp_mb
+	 * PageCgroupUsed && add to memcg LRU	PageLRU && add to memcg LRU
+	 *
+	 * Ensure that one of the two sides adds the page to the memcg
+	 * LRU during a race.
+	 */
+	smp_mb();
 	if (!PageCgroupUsed(pc))
 		return;
 	/* Ensure pc->mem_cgroup is visible after reading PCG_USED. */
@@ -1044,7 +1057,16 @@ static void mem_cgroup_lru_add_after_commit(struct page *page)
 	unsigned long flags;
 	struct zone *zone = page_zone(page);
 	struct page_cgroup *pc = lookup_page_cgroup(page);
-
+	/*
+	 * putback:				charge:
+	 * SetPageLRU				SetPageCgroupUsed
+	 * smp_mb				smp_mb
+	 * PageCgroupUsed && add to memcg LRU	PageLRU && add to memcg LRU
+	 *
+	 * Ensure that one of the two sides adds the page to the memcg
+	 * LRU during a race.
+	 */
+	smp_mb();
 	/* taking care of that the page is added to LRU while we commit it */
 	if (likely(!PageLRU(page)))
 		return;