From a18e6e6e150a98b9ce3e9acabeff407e7b6ba0c0 Mon Sep 17 00:00:00 2001
From: Johannes Weiner <hannes@cmpxchg.org>
Date: Thu, 29 Apr 2021 22:56:17 -0700
Subject: [PATCH] mm: memcontrol: privatize memcg_page_state query functions
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There are no users outside of the memory controller itself. The rest
of the kernel cares either about node or lruvec stats.

Link: https://lkml.kernel.org/r/20210209163304.77088-4-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Reviewed-by: Roman Gushchin <guro@fb.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 include/linux/memcontrol.h | 44 --------------------------------------
 mm/memcontrol.c            | 32 +++++++++++++++++++++++++++
 2 files changed, 32 insertions(+), 44 deletions(-)

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 149dc2fd97a6..9a02aabd0000 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -864,39 +864,6 @@ extern bool cgroup_memory_noswap;
 void lock_page_memcg(struct page *page);
 void unlock_page_memcg(struct page *page);
 
-/*
- * idx can be of type enum memcg_stat_item or node_stat_item.
- * Keep in sync with memcg_exact_page_state().
- */
-static inline unsigned long memcg_page_state(struct mem_cgroup *memcg, int idx)
-{
-	long x = atomic_long_read(&memcg->vmstats[idx]);
-#ifdef CONFIG_SMP
-	if (x < 0)
-		x = 0;
-#endif
-	return x;
-}
-
-/*
- * idx can be of type enum memcg_stat_item or node_stat_item.
- * Keep in sync with memcg_exact_page_state().
- */
-static inline unsigned long memcg_page_state_local(struct mem_cgroup *memcg,
-						   int idx)
-{
-	long x = 0;
-	int cpu;
-
-	for_each_possible_cpu(cpu)
-		x += per_cpu(memcg->vmstats_local->stat[idx], cpu);
-#ifdef CONFIG_SMP
-	if (x < 0)
-		x = 0;
-#endif
-	return x;
-}
-
 void __mod_memcg_state(struct mem_cgroup *memcg, int idx, int val);
 
 /* idx can be of type enum memcg_stat_item or node_stat_item */
@@ -1322,17 +1289,6 @@ static inline void mem_cgroup_print_oom_group(struct mem_cgroup *memcg)
 {
 }
 
-static inline unsigned long memcg_page_state(struct mem_cgroup *memcg, int idx)
-{
-	return 0;
-}
-
-static inline unsigned long memcg_page_state_local(struct mem_cgroup *memcg,
-						   int idx)
-{
-	return 0;
-}
-
 static inline void __mod_memcg_state(struct mem_cgroup *memcg,
 				     int idx,
 				     int nr)
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index b4a73c41312e..56d1c6e58c3b 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -789,6 +789,38 @@ void __mod_memcg_state(struct mem_cgroup *memcg, int idx, int val)
 	__this_cpu_write(memcg->vmstats_percpu->stat[idx], x);
 }
 
+/*
+ * idx can be of type enum memcg_stat_item or node_stat_item.
+ * Keep in sync with memcg_exact_page_state().
+ */
+static unsigned long memcg_page_state(struct mem_cgroup *memcg, int idx)
+{
+	long x = atomic_long_read(&memcg->vmstats[idx]);
+#ifdef CONFIG_SMP
+	if (x < 0)
+		x = 0;
+#endif
+	return x;
+}
+
+/*
+ * idx can be of type enum memcg_stat_item or node_stat_item.
+ * Keep in sync with memcg_exact_page_state().
+ */
+static unsigned long memcg_page_state_local(struct mem_cgroup *memcg, int idx)
+{
+	long x = 0;
+	int cpu;
+
+	for_each_possible_cpu(cpu)
+		x += per_cpu(memcg->vmstats_local->stat[idx], cpu);
+#ifdef CONFIG_SMP
+	if (x < 0)
+		x = 0;
+#endif
+	return x;
+}
+
 static struct mem_cgroup_per_node *
 parent_nodeinfo(struct mem_cgroup_per_node *pn, int nid)
 {