From: Tal Zussman <tz2294@columbia.edu>
To: Johannes Weiner <hannes@cmpxchg.org>,
Michal Hocko <mhocko@kernel.org>,
Roman Gushchin <roman.gushchin@linux.dev>,
Shakeel Butt <shakeel.butt@linux.dev>,
Muchun Song <muchun.song@linux.dev>,
Andrew Morton <akpm@linux-foundation.org>,
Chris Li <chrisl@kernel.org>, Kairui Song <kasong@tencent.com>,
Kemeng Shi <shikemeng@huaweicloud.com>,
Nhat Pham <nphamcs@gmail.com>, Baoquan He <baoquan.he@linux.dev>,
Barry Song <baohua@kernel.org>,
Youngjun Park <youngjun.park@lge.com>,
David Hildenbrand <david@kernel.org>,
Lorenzo Stoakes <ljs@kernel.org>,
"Liam R. Howlett" <liam@infradead.org>,
Vlastimil Babka <vbabka@kernel.org>,
Mike Rapoport <rppt@kernel.org>,
Suren Baghdasaryan <surenb@google.com>,
Qi Zheng <qi.zheng@linux.dev>,
Axel Rasmussen <axelrasmussen@google.com>,
Yuanchu Xie <yuanchu@google.com>, Wei Xu <weixugc@google.com>,
"Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: cgroups@vger.kernel.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org, Tal Zussman <tz2294@columbia.edu>
Subject: [PATCH 03/11] mm: memcontrol: constify the lruvec helpers
Date: Wed, 02 Sep 2026 15:27:49 -0400 [thread overview]
Message-ID: <20260902-folio_memcg-const-v1-3-e2c1da22246d@columbia.edu> (raw)
In-Reply-To: <20260902-folio_memcg-const-v1-0-e2c1da22246d@columbia.edu>
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@columbia.edu>
---
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
next prev parent reply other threads:[~2026-09-02 19:28 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-02 19:27 [PATCH 00/11] mm: memcontrol: constify the read side of the memcg API Tal Zussman
2026-09-02 19:27 ` [PATCH 01/11] mm: memcontrol: take a const folio in folio_memcg() and friends Tal Zussman
2026-09-02 19:27 ` [PATCH 02/11] mm: memcontrol: constify obj_cgroup_memcg() " Tal Zussman
2026-09-02 19:27 ` Tal Zussman [this message]
2026-09-04 21:35 ` [PATCH 03/11] mm: memcontrol: constify the lruvec helpers Tal Zussman
2026-09-02 19:27 ` [PATCH 04/11] mm/page_io: take a const folio in bio_associate_blkg_from_folio() Tal Zussman
2026-09-02 19:27 ` [PATCH 05/11] mm: memcontrol: constify the mem_cgroup accessors Tal Zussman
2026-09-02 19:27 ` [PATCH 06/11] mm: page_counter: constify page_counter_read() and page_counter_margin() Tal Zussman
2026-09-02 19:27 ` [PATCH 07/11] mm: memcontrol: constify the reclaim protection helpers Tal Zussman
2026-09-02 19:27 ` [PATCH 08/11] mm: memcontrol: constify the memcg and lruvec stat readers Tal Zussman
2026-09-04 21:42 ` Tal Zussman
2026-09-02 19:27 ` [PATCH 09/11] mm: memcontrol: constify the swap accounting helpers Tal Zussman
2026-09-02 19:27 ` [PATCH 10/11] mm: memcontrol: constify mem_cgroup_swappiness() and mem_cgroup_get_max() Tal Zussman
2026-09-02 19:27 ` [PATCH 11/11] mm: memcontrol: constify the zswap and socket pressure helpers Tal Zussman
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