[PATCH 03/11] mm: memcontrol: constify the lruvec helpers

[Tal Zussman]

The lruvec lookup helpers only read from the memcg, folio, or lruvec
they are given. Constify them, along with lruvec_pgdat().

Signed-off-by: Tal Zussman <tz2294@xxxxxxxxxxxx>
---
 include/linux/memcontrol.h | 34 +++++++++++++++++-----------------
 include/linux/mmzone.h     |  2 +-
 mm/memcontrol.c            |  6 +++---
 3 files changed, 21 insertions(+), 21 deletions(-)

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 2b3b62e84ab2..4b7cc97e45b2 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -688,7 +688,7 @@ void mem_cgroup_migrate(struct folio *old, struct folio *new);
  * @pgdat combination. This can be the node lruvec, if the memory
  * controller is disabled.
  */
-static inline struct lruvec *mem_cgroup_lruvec(struct mem_cgroup *memcg,
+static inline struct lruvec *mem_cgroup_lruvec(const struct mem_cgroup *memcg,
 					       struct pglist_data *pgdat)
 {
 	struct mem_cgroup_per_node *mz;
@@ -729,7 +729,7 @@ static inline struct lruvec *mem_cgroup_lruvec(struct mem_cgroup *memcg,
  * their binding is stable if the returned lruvec matches the one the caller has
  * locked. Useful for lock batching.
  */
-static inline struct lruvec *folio_lruvec(struct folio *folio)
+static inline struct lruvec *folio_lruvec(const struct folio *folio)
 {
 	struct mem_cgroup *memcg = folio_memcg(folio);
 
@@ -745,9 +745,9 @@ struct mem_cgroup *get_mem_cgroup_from_current(void);
 
 struct mem_cgroup *get_mem_cgroup_from_folio(const struct folio *folio);
 
-struct lruvec *folio_lruvec_lock(struct folio *folio);
-struct lruvec *folio_lruvec_lock_irq(struct folio *folio);
-struct lruvec *folio_lruvec_lock_irqsave(struct folio *folio,
+struct lruvec *folio_lruvec_lock(const struct folio *folio);
+struct lruvec *folio_lruvec_lock_irq(const struct folio *folio);
+struct lruvec *folio_lruvec_lock_irqsave(const struct folio *folio,
 						unsigned long *flags);
 
 static inline
@@ -827,7 +827,7 @@ static inline struct mem_cgroup *mem_cgroup_from_seq(struct seq_file *m)
 	return mem_cgroup_from_css(seq_css(m));
 }
 
-static inline struct mem_cgroup *lruvec_memcg(struct lruvec *lruvec)
+static inline struct mem_cgroup *lruvec_memcg(const struct lruvec *lruvec)
 {
 	struct mem_cgroup_per_node *mz;
 
@@ -885,7 +885,7 @@ void mem_cgroup_update_lru_size(struct lruvec *lruvec, enum lru_list lru,
 		int zid, long nr_pages);
 
 static inline
-unsigned long mem_cgroup_get_zone_lru_size(struct lruvec *lruvec,
+unsigned long mem_cgroup_get_zone_lru_size(const struct lruvec *lruvec,
 		enum lru_list lru, int zone_idx)
 {
 	struct mem_cgroup_per_node *mz;
@@ -1175,13 +1175,13 @@ static inline void mem_cgroup_migrate(struct folio *old, struct folio *new)
 {
 }
 
-static inline struct lruvec *mem_cgroup_lruvec(struct mem_cgroup *memcg,
+static inline struct lruvec *mem_cgroup_lruvec(const struct mem_cgroup *memcg,
 					       struct pglist_data *pgdat)
 {
 	return &pgdat->__lruvec;
 }
 
-static inline struct lruvec *folio_lruvec(struct folio *folio)
+static inline struct lruvec *folio_lruvec(const struct folio *folio)
 {
 	struct pglist_data *pgdat = folio_pgdat(folio);
 	return &pgdat->__lruvec;
@@ -1241,7 +1241,7 @@ static inline void mem_cgroup_put(struct mem_cgroup *memcg)
 {
 }
 
-static inline struct lruvec *folio_lruvec_lock(struct folio *folio)
+static inline struct lruvec *folio_lruvec_lock(const struct folio *folio)
 {
 	struct pglist_data *pgdat = folio_pgdat(folio);
 
@@ -1250,7 +1250,7 @@ static inline struct lruvec *folio_lruvec_lock(struct folio *folio)
 	return &pgdat->__lruvec;
 }
 
-static inline struct lruvec *folio_lruvec_lock_irq(struct folio *folio)
+static inline struct lruvec *folio_lruvec_lock_irq(const struct folio *folio)
 {
 	struct pglist_data *pgdat = folio_pgdat(folio);
 
@@ -1259,7 +1259,7 @@ static inline struct lruvec *folio_lruvec_lock_irq(struct folio *folio)
 	return &pgdat->__lruvec;
 }
 
-static inline struct lruvec *folio_lruvec_lock_irqsave(struct folio *folio,
+static inline struct lruvec *folio_lruvec_lock_irqsave(const struct folio *folio,
 		unsigned long *flagsp)
 {
 	struct pglist_data *pgdat = folio_pgdat(folio);
@@ -1314,7 +1314,7 @@ static inline struct mem_cgroup *mem_cgroup_from_seq(struct seq_file *m)
 	return NULL;
 }
 
-static inline struct mem_cgroup *lruvec_memcg(struct lruvec *lruvec)
+static inline struct mem_cgroup *lruvec_memcg(const struct lruvec *lruvec)
 {
 	return NULL;
 }
@@ -1325,7 +1325,7 @@ static inline bool mem_cgroup_online(struct mem_cgroup *memcg)
 }
 
 static inline
-unsigned long mem_cgroup_get_zone_lru_size(struct lruvec *lruvec,
+unsigned long mem_cgroup_get_zone_lru_size(const struct lruvec *lruvec,
 		enum lru_list lru, int zone_idx)
 {
 	return 0;
@@ -1465,7 +1465,7 @@ static inline void mem_cgroup_flush_workqueue(void) { }
 static inline int mem_cgroup_init(void) { return 0; }
 #endif /* CONFIG_MEMCG */
 
-static inline struct lruvec *parent_lruvec(struct lruvec *lruvec)
+static inline struct lruvec *parent_lruvec(const struct lruvec *lruvec)
 {
 	struct mem_cgroup *memcg;
 
@@ -1528,8 +1528,8 @@ static inline void lruvec_unlock_irqrestore(struct lruvec *lruvec, unsigned long
 }
 
 /* Test requires a stable folio->memcg binding, see folio_memcg() */
-static inline bool folio_matches_lruvec(struct folio *folio,
-		struct lruvec *lruvec)
+static inline bool folio_matches_lruvec(const struct folio *folio,
+		const struct lruvec *lruvec)
 {
 	return lruvec_pgdat(lruvec) == folio_pgdat(folio) &&
 	       lruvec_memcg(lruvec) == folio_memcg(folio);
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 84e237f2c17d..8e1e3a50757a 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -1657,7 +1657,7 @@ extern void init_currently_empty_zone(struct zone *zone, unsigned long start_pfn
 
 extern void lruvec_init(struct lruvec *lruvec);
 
-static inline struct pglist_data *lruvec_pgdat(struct lruvec *lruvec)
+static inline struct pglist_data *lruvec_pgdat(const struct lruvec *lruvec)
 {
 #ifdef CONFIG_MEMCG
 	return lruvec->pgdat;
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index b9bf655cdd2d..e2845f761e37 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1441,7 +1441,7 @@ void mem_cgroup_scan_tasks(struct mem_cgroup *memcg,
  *
  * Return: The lruvec this folio is on with its lock held and rcu read lock held.
  */
-struct lruvec *folio_lruvec_lock(struct folio *folio)
+struct lruvec *folio_lruvec_lock(const struct folio *folio)
 {
 	struct lruvec *lruvec;
 
@@ -1469,7 +1469,7 @@ struct lruvec *folio_lruvec_lock(struct folio *folio)
  * Return: The lruvec this folio is on with its lock held and interrupts
  * disabled and rcu read lock held.
  */
-struct lruvec *folio_lruvec_lock_irq(struct folio *folio)
+struct lruvec *folio_lruvec_lock_irq(const struct folio *folio)
 {
 	struct lruvec *lruvec;
 
@@ -1498,7 +1498,7 @@ struct lruvec *folio_lruvec_lock_irq(struct folio *folio)
  * Return: The lruvec this folio is on with its lock held and interrupts
  * disabled and rcu read lock held.
  */
-struct lruvec *folio_lruvec_lock_irqsave(struct folio *folio,
+struct lruvec *folio_lruvec_lock_irqsave(const struct folio *folio,
 		unsigned long *flags)
 {
 	struct lruvec *lruvec;

-- 
2.39.5