[PATCH v3 28/30 fix 1/2] mm: memcontrol: fix lruvec_stats->state_local reparenting

From: Qi Zheng

Date: Thu Jan 15 2026 - 05:42:19 EST


From: Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx>

Signed-off-by: Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx>
---
include/linux/memcontrol.h | 2 --
mm/memcontrol-v1.c | 8 --------
mm/memcontrol-v1.h | 5 ++++-
mm/memcontrol.c | 19 ++++++++-----------
4 files changed, 12 insertions(+), 22 deletions(-)

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 1fe554eec1e25..e0b84b109b7ac 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -944,8 +944,6 @@ bool memcg_vm_event_item_valid(enum vm_event_item idx);
unsigned long lruvec_page_state(struct lruvec *lruvec, enum node_stat_item idx);
unsigned long lruvec_page_state_local(struct lruvec *lruvec,
enum node_stat_item idx);
-void reparent_memcg_lruvec_state_local(struct mem_cgroup *memcg,
- struct mem_cgroup *parent, int idx);

void mem_cgroup_flush_stats(struct mem_cgroup *memcg);
void mem_cgroup_flush_stats_ratelimited(struct mem_cgroup *memcg);
diff --git a/mm/memcontrol-v1.c b/mm/memcontrol-v1.c
index 03b924920d6a5..daf9bad8c45ea 100644
--- a/mm/memcontrol-v1.c
+++ b/mm/memcontrol-v1.c
@@ -1909,14 +1909,6 @@ void reparent_memcg1_state_local(struct mem_cgroup *memcg, struct mem_cgroup *pa
reparent_memcg_state_local(memcg, parent, memcg1_stats[i]);
}

-void reparent_memcg1_lruvec_state_local(struct mem_cgroup *memcg, struct mem_cgroup *parent)
-{
- int i;
-
- for (i = 0; i < ARRAY_SIZE(memcg1_stats); i++)
- reparent_memcg_lruvec_state_local(memcg, parent, memcg1_stats[i]);
-}
-
void memcg1_stat_format(struct mem_cgroup *memcg, struct seq_buf *s)
{
unsigned long memory, memsw;
diff --git a/mm/memcontrol-v1.h b/mm/memcontrol-v1.h
index 45528195d3578..5b1188f3d4173 100644
--- a/mm/memcontrol-v1.h
+++ b/mm/memcontrol-v1.h
@@ -75,7 +75,6 @@ void memcg1_uncharge_batch(struct mem_cgroup *memcg, unsigned long pgpgout,

void memcg1_stat_format(struct mem_cgroup *memcg, struct seq_buf *s);
void reparent_memcg1_state_local(struct mem_cgroup *memcg, struct mem_cgroup *parent);
-void reparent_memcg1_lruvec_state_local(struct mem_cgroup *memcg, struct mem_cgroup *parent);

void memcg1_account_kmem(struct mem_cgroup *memcg, int nr_pages);
static inline bool memcg1_tcpmem_active(struct mem_cgroup *memcg)
@@ -116,6 +115,10 @@ static inline void memcg1_uncharge_batch(struct mem_cgroup *memcg,

static inline void memcg1_stat_format(struct mem_cgroup *memcg, struct seq_buf *s) {}

+static inline void reparent_memcg1_state_local(struct mem_cgroup *memcg, struct mem_cgroup *parent)
+{
+}
+
static inline void memcg1_account_kmem(struct mem_cgroup *memcg, int nr_pages) {}
static inline bool memcg1_tcpmem_active(struct mem_cgroup *memcg) { return false; }
static inline bool memcg1_charge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages,
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 7333a37830051..b7b35143d4d2d 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -225,13 +225,13 @@ static inline struct obj_cgroup *__memcg_reparent_objcgs(struct mem_cgroup *memc
return objcg;
}

-#ifdef CONFIG_MEMCG_V1
+static void reparent_memcg_lruvec_state_local(struct mem_cgroup *memcg,
+ struct mem_cgroup *parent, int idx);
static void __mem_cgroup_flush_stats(struct mem_cgroup *memcg, bool force);

static inline void reparent_state_local(struct mem_cgroup *memcg, struct mem_cgroup *parent)
{
- if (cgroup_subsys_on_dfl(memory_cgrp_subsys))
- return;
+ int i;

synchronize_rcu();

@@ -239,13 +239,10 @@ static inline void reparent_state_local(struct mem_cgroup *memcg, struct mem_cgr

/* The following counts are all non-hierarchical and need to be reparented. */
reparent_memcg1_state_local(memcg, parent);
- reparent_memcg1_lruvec_state_local(memcg, parent);
-}
-#else
-static inline void reparent_state_local(struct mem_cgroup *memcg, struct mem_cgroup *parent)
-{
+
+ for (i = 0; i < NR_LRU_LISTS; i++)
+ reparent_memcg_lruvec_state_local(memcg, parent, i);
}
-#endif

static inline void reparent_locks(struct mem_cgroup *memcg, struct mem_cgroup *parent)
{
@@ -510,8 +507,8 @@ unsigned long lruvec_page_state_local(struct lruvec *lruvec,
return x;
}

-void reparent_memcg_lruvec_state_local(struct mem_cgroup *memcg,
- struct mem_cgroup *parent, int idx)
+static void reparent_memcg_lruvec_state_local(struct mem_cgroup *memcg,
+ struct mem_cgroup *parent, int idx)
{
int i = memcg_stats_index(idx);
int nid;
--
2.20.1