mm: memcontrol: refactor mod_memcg_state() and mod_memcg_lruvec_state()

Refactor the memcg_reparent_objcgs() to facilitate subsequent reparenting
non-hierarchical stats.

Link: https://lore.kernel.org/7f8bd3aacec2270b9453428fc8585cca9f10751e.1772711148.git.zhengqi.arch@bytedance.com
Co-developed-by: Yosry Ahmed <yosry@kernel.org>
Signed-off-by: Yosry Ahmed <yosry@kernel.org>
Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Allen Pais <apais@linux.microsoft.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Chen Ridong <chenridong@huawei.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Hamza Mahfooz <hamzamahfooz@linux.microsoft.com>
Cc: Harry Yoo <harry.yoo@oracle.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Imran Khan <imran.f.khan@oracle.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kamalesh Babulal <kamalesh.babulal@oracle.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam Howlett <Liam.Howlett@oracle.com>
Cc: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Michal Koutný <mkoutny@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Usama Arif <usamaarif642@gmail.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Wei Xu <weixugc@google.com>
Cc: Yuanchu Xie <yuanchu@google.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

1 files changed, 31 insertions, 19 deletions

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index e43ca8da8daf..271d4c6307b6 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -717,21 +717,12 @@ static int memcg_state_val_in_pages(int idx, int val)
 		return max(val * unit / PAGE_SIZE, 1UL);
 }
 
-/**
- * mod_memcg_state - update cgroup memory statistics
- * @memcg: the memory cgroup
- * @idx: the stat item - can be enum memcg_stat_item or enum node_stat_item
- * @val: delta to add to the counter, can be negative
- */
-void mod_memcg_state(struct mem_cgroup *memcg, enum memcg_stat_item idx,
-		       int val)
+static void __mod_memcg_state(struct mem_cgroup *memcg,
+			      enum memcg_stat_item idx, int val)
 {
 	int i = memcg_stats_index(idx);
 	int cpu;
 
-	if (mem_cgroup_disabled())
-		return;
-
 	if (WARN_ONCE(BAD_STAT_IDX(i), "%s: missing stat item %d\n", __func__, idx))
 		return;
 
@@ -745,6 +736,21 @@ void mod_memcg_state(struct mem_cgroup *memcg, enum memcg_stat_item idx,
 	put_cpu();
 }
 
+/**
+ * mod_memcg_state - update cgroup memory statistics
+ * @memcg: the memory cgroup
+ * @idx: the stat item - can be enum memcg_stat_item or enum node_stat_item
+ * @val: delta to add to the counter, can be negative
+ */
+void mod_memcg_state(struct mem_cgroup *memcg, enum memcg_stat_item idx,
+		       int val)
+{
+	if (mem_cgroup_disabled())
+		return;
+
+	__mod_memcg_state(memcg, idx, val);
+}
+
 #ifdef CONFIG_MEMCG_V1
 /* idx can be of type enum memcg_stat_item or node_stat_item. */
 unsigned long memcg_page_state_local(struct mem_cgroup *memcg, int idx)
@@ -764,21 +770,16 @@ unsigned long memcg_page_state_local(struct mem_cgroup *memcg, int idx)
 }
 #endif
 
-static void mod_memcg_lruvec_state(struct lruvec *lruvec,
-				     enum node_stat_item idx,
-				     int val)
+static void __mod_memcg_lruvec_state(struct mem_cgroup_per_node *pn,
+				     enum node_stat_item idx, int val)
 {
-	struct mem_cgroup_per_node *pn;
-	struct mem_cgroup *memcg;
+	struct mem_cgroup *memcg = pn->memcg;
 	int i = memcg_stats_index(idx);
 	int cpu;
 
 	if (WARN_ONCE(BAD_STAT_IDX(i), "%s: missing stat item %d\n", __func__, idx))
 		return;
 
-	pn = container_of(lruvec, struct mem_cgroup_per_node, lruvec);
-	memcg = pn->memcg;
-
 	cpu = get_cpu();
 
 	/* Update memcg */
@@ -794,6 +795,17 @@ static void mod_memcg_lruvec_state(struct lruvec *lruvec,
 	put_cpu();
 }
 
+static void mod_memcg_lruvec_state(struct lruvec *lruvec,
+				     enum node_stat_item idx,
+				     int val)
+{
+	struct mem_cgroup_per_node *pn;
+
+	pn = container_of(lruvec, struct mem_cgroup_per_node, lruvec);
+
+	__mod_memcg_lruvec_state(pn, idx, val);
+}
+
 /**
  * mod_lruvec_state - update lruvec memory statistics
  * @lruvec: the lruvec