1 files changed, 44 insertions, 10 deletions

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 78fd7cfb4f92..1f204a262054 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -671,6 +671,8 @@ static void flush_memcg_stats_dwork(struct work_struct *w)
 
 /* Subset of vm_event_item to report for memcg event stats */
 static const unsigned int memcg_vm_event_stat[] = {
+	PGPGIN,
+	PGPGOUT,
 	PGSCAN_KSWAPD,
 	PGSCAN_DIRECT,
 	PGSTEAL_KSWAPD,
@@ -692,14 +694,30 @@ static const unsigned int memcg_vm_event_stat[] = {
 #endif
 };
 
+#define NR_MEMCG_EVENTS ARRAY_SIZE(memcg_vm_event_stat)
+static int mem_cgroup_events_index[NR_VM_EVENT_ITEMS] __read_mostly;
+
+static void init_memcg_events(void)
+{
+	int i;
+
+	for (i = 0; i < NR_MEMCG_EVENTS; ++i)
+		mem_cgroup_events_index[memcg_vm_event_stat[i]] = i + 1;
+}
+
+static inline int memcg_events_index(enum vm_event_item idx)
+{
+	return mem_cgroup_events_index[idx] - 1;
+}
+
 struct memcg_vmstats_percpu {
 	/* Local (CPU and cgroup) page state & events */
 	long			state[MEMCG_NR_STAT];
-	unsigned long		events[NR_VM_EVENT_ITEMS];
+	unsigned long		events[NR_MEMCG_EVENTS];
 
 	/* Delta calculation for lockless upward propagation */
 	long			state_prev[MEMCG_NR_STAT];
-	unsigned long		events_prev[NR_VM_EVENT_ITEMS];
+	unsigned long		events_prev[NR_MEMCG_EVENTS];
 
 	/* Cgroup1: threshold notifications & softlimit tree updates */
 	unsigned long		nr_page_events;
@@ -709,11 +727,11 @@ struct memcg_vmstats_percpu {
 struct memcg_vmstats {
 	/* Aggregated (CPU and subtree) page state & events */
 	long			state[MEMCG_NR_STAT];
-	unsigned long		events[NR_VM_EVENT_ITEMS];
+	unsigned long		events[NR_MEMCG_EVENTS];
 
 	/* Pending child counts during tree propagation */
 	long			state_pending[MEMCG_NR_STAT];
-	unsigned long		events_pending[NR_VM_EVENT_ITEMS];
+	unsigned long		events_pending[NR_MEMCG_EVENTS];
 };
 
 unsigned long memcg_page_state(struct mem_cgroup *memcg, int idx)
@@ -873,27 +891,37 @@ void __mod_lruvec_kmem_state(void *p, enum node_stat_item idx, int val)
 void __count_memcg_events(struct mem_cgroup *memcg, enum vm_event_item idx,
 			  unsigned long count)
 {
-	if (mem_cgroup_disabled())
+	int index = memcg_events_index(idx);
+
+	if (mem_cgroup_disabled() || index < 0)
 		return;
 
 	memcg_stats_lock();
-	__this_cpu_add(memcg->vmstats_percpu->events[idx], count);
+	__this_cpu_add(memcg->vmstats_percpu->events[index], count);
 	memcg_rstat_updated(memcg, count);
 	memcg_stats_unlock();
 }
 
 static unsigned long memcg_events(struct mem_cgroup *memcg, int event)
 {
-	return READ_ONCE(memcg->vmstats->events[event]);
+	int index = memcg_events_index(event);
+
+	if (index < 0)
+		return 0;
+	return READ_ONCE(memcg->vmstats->events[index]);
 }
 
 static unsigned long memcg_events_local(struct mem_cgroup *memcg, int event)
 {
 	long x = 0;
 	int cpu;
+	int index = memcg_events_index(event);
+
+	if (index < 0)
+		return 0;
 
 	for_each_possible_cpu(cpu)
-		x += per_cpu(memcg->vmstats_percpu->events[event], cpu);
+		x += per_cpu(memcg->vmstats_percpu->events[index], cpu);
 	return x;
 }
 
@@ -1564,10 +1592,15 @@ static void memory_stat_format(struct mem_cgroup *memcg, char *buf, int bufsize)
 		       memcg_events(memcg, PGSTEAL_KSWAPD) +
 		       memcg_events(memcg, PGSTEAL_DIRECT));
 
-	for (i = 0; i < ARRAY_SIZE(memcg_vm_event_stat); i++)
+	for (i = 0; i < ARRAY_SIZE(memcg_vm_event_stat); i++) {
+		if (memcg_vm_event_stat[i] == PGPGIN ||
+		    memcg_vm_event_stat[i] == PGPGOUT)
+			continue;
+
 		seq_buf_printf(&s, "%s %lu\n",
 			       vm_event_name(memcg_vm_event_stat[i]),
 			       memcg_events(memcg, memcg_vm_event_stat[i]));
+	}
 
 	/* The above should easily fit into one page */
 	WARN_ON_ONCE(seq_buf_has_overflowed(&s));
@@ -5309,6 +5342,7 @@ mem_cgroup_css_alloc(struct cgroup_subsys_state *parent_css)
 		page_counter_init(&memcg->kmem, &parent->kmem);
 		page_counter_init(&memcg->tcpmem, &parent->tcpmem);
 	} else {
+		init_memcg_events();
 		page_counter_init(&memcg->memory, NULL);
 		page_counter_init(&memcg->swap, NULL);
 		page_counter_init(&memcg->kmem, NULL);
@@ -5477,7 +5511,7 @@ static void mem_cgroup_css_rstat_flush(struct cgroup_subsys_state *css, int cpu)
 			parent->vmstats->state_pending[i] += delta;
 	}
 
-	for (i = 0; i < NR_VM_EVENT_ITEMS; i++) {
+	for (i = 0; i < NR_MEMCG_EVENTS; i++) {
 		delta = memcg->vmstats->events_pending[i];
 		if (delta)
 			memcg->vmstats->events_pending[i] = 0;