[PATCH 0/2] mm: memcontrol: remove two unused helpers

[PATCH 0/2] mm: memcontrol: remove two unused helpers

[Tal Zussman]

They were happily unused until I decided to disturb their peace.

---
Tal Zussman (2):
      mm: memcontrol: remove mod_memcg_page_state()
      mm: memcontrol: remove page_memcg_check()

 include/linux/memcontrol.h | 32 --------------------------------
 1 file changed, 32 deletions(-)
---
base-commit: ad9f2d463666c64e94b04be5263c9bf8f9f96fb7
change-id: 20261014-memcg-unused-page-helpers-c43a866ee0ba

Best regards,
--  
Tal Zussman <tz2294@columbia.edu>

[PATCH 1/2] mm: memcontrol: remove mod_memcg_page_state()

[Tal Zussman]

The last caller was removed in commit c466412c73c3 ("mm: memcontrol:
switch to native NR_VMALLOC vmstat counter"). Remove it.

Signed-off-by: Tal Zussman <tz2294@columbia.edu>
---
 include/linux/memcontrol.h | 20 --------------------
 1 file changed, 20 deletions(-)

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 74110a324f9e..b65a2d0fca3a 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -957,21 +957,6 @@ void mem_cgroup_print_oom_group(struct mem_cgroup *memcg);
 void mod_memcg_state(struct mem_cgroup *memcg,
 		     enum memcg_stat_item idx, int val);
 
-static inline void mod_memcg_page_state(const struct page *page,
-					enum memcg_stat_item idx, int val)
-{
-	struct mem_cgroup *memcg;
-
-	if (mem_cgroup_disabled())
-		return;
-
-	rcu_read_lock();
-	memcg = folio_memcg(page_folio(page));
-	if (memcg)
-		mod_memcg_state(memcg, idx, val);
-	rcu_read_unlock();
-}
-
 unsigned long memcg_events(const struct mem_cgroup *memcg, int event);
 unsigned long memcg_page_state(const struct mem_cgroup *memcg, int idx);
 unsigned long memcg_page_state_output(const struct mem_cgroup *memcg, int item);
@@ -1412,11 +1397,6 @@ static inline void mod_memcg_state(struct mem_cgroup *memcg,
 {
 }
 
-static inline void mod_memcg_page_state(const struct page *page,
-					enum memcg_stat_item idx, int val)
-{
-}
-
 static inline unsigned long memcg_page_state(const struct mem_cgroup *memcg, int idx)
 {
 	return 0;

-- 
2.39.5

Re: [PATCH 1/2] mm: memcontrol: remove mod_memcg_page_state()

[Harry Yoo]

On Wed, Oct 14, 2026 at 01:08:20PM -0400, Tal Zussman wrote:
> The last caller was removed in commit c466412c73c3 ("mm: memcontrol:
> switch to native NR_VMALLOC vmstat counter"). Remove it.
> 
> Signed-off-by: Tal Zussman <tz2294@columbia.edu>
> ---

Looks good to me,
Reviewed-by: Harry Yoo (Meta) <harry@kernel.org>

-- 
Cheers,
Harry / Hyeonggon

Re: [PATCH 1/2] mm: memcontrol: remove mod_memcg_page_state()

[Shakeel Butt]

On Wed, Oct 14, 2026 at 01:08:20PM -0400, Tal Zussman wrote:
> The last caller was removed in commit c466412c73c3 ("mm: memcontrol:
> switch to native NR_VMALLOC vmstat counter"). Remove it.
> 
> Signed-off-by: Tal Zussman <tz2294@columbia.edu>

Acked-by: Shakeel Butt <shakeel.butt@linux.dev>

Re: [PATCH 1/2] mm: memcontrol: remove mod_memcg_page_state()

[Johannes Weiner]

On Wed, Oct 14, 2026 at 01:08:20PM -0400, Tal Zussman wrote:
> The last caller was removed in commit c466412c73c3 ("mm: memcontrol:
> switch to native NR_VMALLOC vmstat counter"). Remove it.
> 
> Signed-off-by: Tal Zussman <tz2294@columbia.edu>

Reviewed-by: Johannes Weiner <hannes@cmpxchg.org>

Thanks Tal

[PATCH 2/2] mm: memcontrol: remove page_memcg_check()

[Tal Zussman]

The last caller was removed in commit 90f095b816e2 ("mm/page_owner: use
memcg_data snapshot to avoid TOCTOU in print_page_owner_memcg()").
Remove it.

Signed-off-by: Tal Zussman <tz2294@columbia.edu>
---
 include/linux/memcontrol.h | 12 ------------
 1 file changed, 12 deletions(-)

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index b65a2d0fca3a..33439e285d94 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -499,13 +499,6 @@ static inline struct mem_cgroup *folio_memcg_check(const struct folio *folio)
 	return obj_cgroup_memcg(objcg);
 }
 
-static inline struct mem_cgroup *page_memcg_check(const struct page *page)
-{
-	if (PageTail(page))
-		return NULL;
-	return folio_memcg_check((const struct folio *)page);
-}
-
 static inline struct mem_cgroup *get_mem_cgroup_from_objcg(const struct obj_cgroup *objcg)
 {
 	struct mem_cgroup *memcg;
@@ -1089,11 +1082,6 @@ static inline struct mem_cgroup *folio_memcg_check(const struct folio *folio)
 	return NULL;
 }
 
-static inline struct mem_cgroup *page_memcg_check(const struct page *page)
-{
-	return NULL;
-}
-
 static inline struct mem_cgroup *get_mem_cgroup_from_objcg(const struct obj_cgroup *objcg)
 {
 	return NULL;

-- 
2.39.5

Re: [PATCH 2/2] mm: memcontrol: remove page_memcg_check()

[Harry Yoo]

On Wed, Oct 14, 2026 at 01:08:21PM -0400, Tal Zussman wrote:
> The last caller was removed in commit 90f095b816e2 ("mm/page_owner: use
> memcg_data snapshot to avoid TOCTOU in print_page_owner_memcg()").
> Remove it.
> 
> Signed-off-by: Tal Zussman <tz2294@columbia.edu>
> ---

Looks good to me,
Reviewed-by: Harry Yoo (Meta) <harry@kernel.org>

-- 
Cheers,
Harry / Hyeonggon

Re: [PATCH 2/2] mm: memcontrol: remove page_memcg_check()

[Shakeel Butt]

On Wed, Oct 14, 2026 at 01:08:21PM -0400, Tal Zussman wrote:
> The last caller was removed in commit 90f095b816e2 ("mm/page_owner: use
> memcg_data snapshot to avoid TOCTOU in print_page_owner_memcg()").
> Remove it.
> 
> Signed-off-by: Tal Zussman <tz2294@columbia.edu>

Acked-by: Shakeel Butt <shakeel.butt@linux.dev>

Re: [PATCH 2/2] mm: memcontrol: remove page_memcg_check()

[Johannes Weiner]

On Wed, Oct 14, 2026 at 01:08:21PM -0400, Tal Zussman wrote:
> The last caller was removed in commit 90f095b816e2 ("mm/page_owner: use
> memcg_data snapshot to avoid TOCTOU in print_page_owner_memcg()").
> Remove it.
> 
> Signed-off-by: Tal Zussman <tz2294@columbia.edu>

Reviewed-by: Johannes Weiner <hannes@cmpxchg.org>