1 files changed, 63 insertions, 121 deletions

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index a82464b6e3d2..9c9dfcf7a6d1 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -89,54 +89,8 @@ enum mem_cgroup_stat_index {
 
 struct mem_cgroup_stat_cpu {
 	s64 count[MEM_CGROUP_STAT_NSTATS];
-} ____cacheline_aligned_in_smp;
-
-struct mem_cgroup_stat {
-	struct mem_cgroup_stat_cpu cpustat[0];
 };
 
-static inline void
-__mem_cgroup_stat_set_safe(struct mem_cgroup_stat_cpu *stat,
-				enum mem_cgroup_stat_index idx, s64 val)
-{
-	stat->count[idx] = val;
-}
-
-static inline s64
-__mem_cgroup_stat_read_local(struct mem_cgroup_stat_cpu *stat,
-				enum mem_cgroup_stat_index idx)
-{
-	return stat->count[idx];
-}
-
-/*
- * For accounting under irq disable, no need for increment preempt count.
- */
-static inline void __mem_cgroup_stat_add_safe(struct mem_cgroup_stat_cpu *stat,
-		enum mem_cgroup_stat_index idx, int val)
-{
-	stat->count[idx] += val;
-}
-
-static s64 mem_cgroup_read_stat(struct mem_cgroup_stat *stat,
-		enum mem_cgroup_stat_index idx)
-{
-	int cpu;
-	s64 ret = 0;
-	for_each_possible_cpu(cpu)
-		ret += stat->cpustat[cpu].count[idx];
-	return ret;
-}
-
-static s64 mem_cgroup_local_usage(struct mem_cgroup_stat *stat)
-{
-	s64 ret;
-
-	ret = mem_cgroup_read_stat(stat, MEM_CGROUP_STAT_CACHE);
-	ret += mem_cgroup_read_stat(stat, MEM_CGROUP_STAT_RSS);
-	return ret;
-}
-
 /*
  * per-zone information in memory controller.
  */
@@ -270,9 +224,9 @@ struct mem_cgroup {
 	unsigned long 	move_charge_at_immigrate;
 
 	/*
-	 * statistics. This must be placed at the end of memcg.
+	 * percpu counter.
 	 */
-	struct mem_cgroup_stat stat;
+	struct mem_cgroup_stat_cpu *stat;
 };
 
 /* Stuffs for move charges at task migration. */
@@ -441,19 +395,14 @@ mem_cgroup_remove_exceeded(struct mem_cgroup *mem,
 static bool mem_cgroup_soft_limit_check(struct mem_cgroup *mem)
 {
 	bool ret = false;
-	int cpu;
 	s64 val;
-	struct mem_cgroup_stat_cpu *cpustat;
 
-	cpu = get_cpu();
-	cpustat = &mem->stat.cpustat[cpu];
-	val = __mem_cgroup_stat_read_local(cpustat, MEM_CGROUP_STAT_SOFTLIMIT);
+	val = this_cpu_read(mem->stat->count[MEM_CGROUP_STAT_SOFTLIMIT]);
 	if (unlikely(val < 0)) {
-		__mem_cgroup_stat_set_safe(cpustat, MEM_CGROUP_STAT_SOFTLIMIT,
+		this_cpu_write(mem->stat->count[MEM_CGROUP_STAT_SOFTLIMIT],
 				SOFTLIMIT_EVENTS_THRESH);
 		ret = true;
 	}
-	put_cpu();
 	return ret;
 }
 
@@ -549,17 +498,31 @@ mem_cgroup_largest_soft_limit_node(struct mem_cgroup_tree_per_zone *mctz)
 	return mz;
 }
 
+static s64 mem_cgroup_read_stat(struct mem_cgroup *mem,
+		enum mem_cgroup_stat_index idx)
+{
+	int cpu;
+	s64 val = 0;
+
+	for_each_possible_cpu(cpu)
+		val += per_cpu(mem->stat->count[idx], cpu);
+	return val;
+}
+
+static s64 mem_cgroup_local_usage(struct mem_cgroup *mem)
+{
+	s64 ret;
+
+	ret = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_RSS);
+	ret += mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_CACHE);
+	return ret;
+}
+
 static void mem_cgroup_swap_statistics(struct mem_cgroup *mem,
 					 bool charge)
 {
 	int val = (charge) ? 1 : -1;
-	struct mem_cgroup_stat *stat = &mem->stat;
-	struct mem_cgroup_stat_cpu *cpustat;
-	int cpu = get_cpu();
-
-	cpustat = &stat->cpustat[cpu];
-	__mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_SWAPOUT, val);
-	put_cpu();
+	this_cpu_add(mem->stat->count[MEM_CGROUP_STAT_SWAPOUT], val);
 }
 
 static void mem_cgroup_charge_statistics(struct mem_cgroup *mem,
@@ -567,26 +530,22 @@ static void mem_cgroup_charge_statistics(struct mem_cgroup *mem,
 					 bool charge)
 {
 	int val = (charge) ? 1 : -1;
-	struct mem_cgroup_stat *stat = &mem->stat;
-	struct mem_cgroup_stat_cpu *cpustat;
-	int cpu = get_cpu();
 
-	cpustat = &stat->cpustat[cpu];
+	preempt_disable();
+
 	if (PageCgroupCache(pc))
-		__mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_CACHE, val);
+		__this_cpu_add(mem->stat->count[MEM_CGROUP_STAT_CACHE], val);
 	else
-		__mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_RSS, val);
+		__this_cpu_add(mem->stat->count[MEM_CGROUP_STAT_RSS], val);
 
 	if (charge)
-		__mem_cgroup_stat_add_safe(cpustat,
-				MEM_CGROUP_STAT_PGPGIN_COUNT, 1);
+		__this_cpu_inc(mem->stat->count[MEM_CGROUP_STAT_PGPGIN_COUNT]);
 	else
-		__mem_cgroup_stat_add_safe(cpustat,
-				MEM_CGROUP_STAT_PGPGOUT_COUNT, 1);
-	__mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_SOFTLIMIT, -1);
-	__mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_THRESHOLDS, -1);
+		__this_cpu_inc(mem->stat->count[MEM_CGROUP_STAT_PGPGOUT_COUNT]);
+	__this_cpu_dec(mem->stat->count[MEM_CGROUP_STAT_SOFTLIMIT]);
+	__this_cpu_dec(mem->stat->count[MEM_CGROUP_STAT_THRESHOLDS]);
 
-	put_cpu();
+	preempt_enable();
 }
 
 static unsigned long mem_cgroup_get_local_zonestat(struct mem_cgroup *mem,
@@ -1244,7 +1203,7 @@ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem,
 				}
 			}
 		}
-		if (!mem_cgroup_local_usage(&victim->stat)) {
+		if (!mem_cgroup_local_usage(victim)) {
 			/* this cgroup's local usage == 0 */
 			css_put(&victim->css);
 			continue;
@@ -1310,9 +1269,6 @@ static void record_last_oom(struct mem_cgroup *mem)
 void mem_cgroup_update_file_mapped(struct page *page, int val)
 {
 	struct mem_cgroup *mem;
-	struct mem_cgroup_stat *stat;
-	struct mem_cgroup_stat_cpu *cpustat;
-	int cpu;
 	struct page_cgroup *pc;
 
 	pc = lookup_page_cgroup(page);
@@ -1328,13 +1284,10 @@ void mem_cgroup_update_file_mapped(struct page *page, int val)
 		goto done;
 
 	/*
-	 * Preemption is already disabled, we don't need get_cpu()
+	 * Preemption is already disabled. We can use __this_cpu_xxx
 	 */
-	cpu = smp_processor_id();
-	stat = &mem->stat;
-	cpustat = &stat->cpustat[cpu];
+	__this_cpu_add(mem->stat->count[MEM_CGROUP_STAT_FILE_MAPPED], val);
 
-	__mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_FILE_MAPPED, val);
 done:
 	unlock_page_cgroup(pc);
 }
@@ -1761,9 +1714,6 @@ static void __mem_cgroup_move_account(struct page_cgroup *pc,
 	struct mem_cgroup *from, struct mem_cgroup *to, bool uncharge)
 {
 	struct page *page;
-	int cpu;
-	struct mem_cgroup_stat *stat;
-	struct mem_cgroup_stat_cpu *cpustat;
 
 	VM_BUG_ON(from == to);
 	VM_BUG_ON(PageLRU(pc->page));
@@ -1773,18 +1723,11 @@ static void __mem_cgroup_move_account(struct page_cgroup *pc,
 
 	page = pc->page;
 	if (page_mapped(page) && !PageAnon(page)) {
-		cpu = smp_processor_id();
-		/* Update mapped_file data for mem_cgroup "from" */
-		stat = &from->stat;
-		cpustat = &stat->cpustat[cpu];
-		__mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_FILE_MAPPED,
-						-1);
-
-		/* Update mapped_file data for mem_cgroup "to" */
-		stat = &to->stat;
-		cpustat = &stat->cpustat[cpu];
-		__mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_FILE_MAPPED,
-						1);
+		/* Update mapped_file data for mem_cgroup */
+		preempt_disable();
+		__this_cpu_dec(from->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]);
+		__this_cpu_inc(to->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]);
+		preempt_enable();
 	}
 	mem_cgroup_charge_statistics(from, pc, false);
 	if (uncharge)
@@ -2885,7 +2828,7 @@ static int
 mem_cgroup_get_idx_stat(struct mem_cgroup *mem, void *data)
 {
 	struct mem_cgroup_idx_data *d = data;
-	d->val += mem_cgroup_read_stat(&mem->stat, d->idx);
+	d->val += mem_cgroup_read_stat(mem, d->idx);
 	return 0;
 }
 
@@ -3134,18 +3077,18 @@ static int mem_cgroup_get_local_stat(struct mem_cgroup *mem, void *data)
 	s64 val;
 
 	/* per cpu stat */
-	val = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_CACHE);
+	val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_CACHE);
 	s->stat[MCS_CACHE] += val * PAGE_SIZE;
-	val = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_RSS);
+	val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_RSS);
 	s->stat[MCS_RSS] += val * PAGE_SIZE;
-	val = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_FILE_MAPPED);
+	val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_FILE_MAPPED);
 	s->stat[MCS_FILE_MAPPED] += val * PAGE_SIZE;
-	val = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_PGPGIN_COUNT);
+	val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_PGPGIN_COUNT);
 	s->stat[MCS_PGPGIN] += val;
-	val = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_PGPGOUT_COUNT);
+	val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_PGPGOUT_COUNT);
 	s->stat[MCS_PGPGOUT] += val;
 	if (do_swap_account) {
-		val = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_SWAPOUT);
+		val = mem_cgroup_read_stat(mem, MEM_CGROUP_STAT_SWAPOUT);
 		s->stat[MCS_SWAP] += val * PAGE_SIZE;
 	}
 
@@ -3276,19 +3219,14 @@ static int mem_cgroup_swappiness_write(struct cgroup *cgrp, struct cftype *cft,
 static bool mem_cgroup_threshold_check(struct mem_cgroup *mem)
 {
 	bool ret = false;
-	int cpu;
 	s64 val;
-	struct mem_cgroup_stat_cpu *cpustat;
 
-	cpu = get_cpu();
-	cpustat = &mem->stat.cpustat[cpu];
-	val = __mem_cgroup_stat_read_local(cpustat, MEM_CGROUP_STAT_THRESHOLDS);
+	val = this_cpu_read(mem->stat->count[MEM_CGROUP_STAT_THRESHOLDS]);
 	if (unlikely(val < 0)) {
-		__mem_cgroup_stat_set_safe(cpustat, MEM_CGROUP_STAT_THRESHOLDS,
+		this_cpu_write(mem->stat->count[MEM_CGROUP_STAT_THRESHOLDS],
 				THRESHOLDS_EVENTS_THRESH);
 		ret = true;
 	}
-	put_cpu();
 	return ret;
 }
 
@@ -3676,17 +3614,12 @@ static void free_mem_cgroup_per_zone_info(struct mem_cgroup *mem, int node)
 	kfree(mem->info.nodeinfo[node]);
 }
 
-static int mem_cgroup_size(void)
-{
-	int cpustat_size = nr_cpu_ids * sizeof(struct mem_cgroup_stat_cpu);
-	return sizeof(struct mem_cgroup) + cpustat_size;
-}
-
 static struct mem_cgroup *mem_cgroup_alloc(void)
 {
 	struct mem_cgroup *mem;
-	int size = mem_cgroup_size();
+	int size = sizeof(struct mem_cgroup);
 
+	/* Can be very big if MAX_NUMNODES is very big */
 	if (size < PAGE_SIZE)
 		mem = kmalloc(size, GFP_KERNEL);
 	else
@@ -3694,6 +3627,14 @@ static struct mem_cgroup *mem_cgroup_alloc(void)
 
 	if (mem)
 		memset(mem, 0, size);
+	mem->stat = alloc_percpu(struct mem_cgroup_stat_cpu);
+	if (!mem->stat) {
+		if (size < PAGE_SIZE)
+			kfree(mem);
+		else
+			vfree(mem);
+		mem = NULL;
+	}
 	return mem;
 }
 
@@ -3718,7 +3659,8 @@ static void __mem_cgroup_free(struct mem_cgroup *mem)
 	for_each_node_state(node, N_POSSIBLE)
 		free_mem_cgroup_per_zone_info(mem, node);
 
-	if (mem_cgroup_size() < PAGE_SIZE)
+	free_percpu(mem->stat);
+	if (sizeof(struct mem_cgroup) < PAGE_SIZE)
 		kfree(mem);
 	else
 		vfree(mem);