[PATCH 7/8] memcg: remove unused mem_cgroup_id() and mem_cgroup_from_id()

Shakeel Butt
2025-12-25T23:23:20Z

Now that all callers have been converted to use either:
- The private ID APIs (mem_cgroup_private_id/mem_cgroup_from_private_id)
for internal kernel objects that outlive their cgroup
- The public cgroup ID APIs (mem_cgroup_ino/mem_cgroup_get_from_ino)
for external interfaces

Remove the unused wrapper functions mem_cgroup_id() and
mem_cgroup_from_id() along with their !CONFIG_MEMCG stubs.

Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
---
include/linux/memcontrol.h | 18 ------------------
mm/memcontrol.c | 5 -----
2 files changed, 23 deletions(-)

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index c823150ec288..3e7d69020b39 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -830,12 +830,6 @@ static inline unsigned short mem_cgroup_private_id(struct mem_cgroup *memcg)
}
struct mem_cgroup *mem_cgroup_from_private_id(unsigned short id);

-static inline unsigned short mem_cgroup_id(struct mem_cgroup *memcg)
-{
- return mem_cgroup_private_id(memcg);
-}
-struct mem_cgroup *mem_cgroup_from_id(unsigned short id);
-
static inline u64 mem_cgroup_ino(struct mem_cgroup *memcg)
{
return memcg ? cgroup_id(memcg->css.cgroup) : 0;
@@ -1282,18 +1276,6 @@ static inline void mem_cgroup_scan_tasks(struct mem_cgroup *memcg,
{
}

-static inline unsigned short mem_cgroup_id(struct mem_cgroup *memcg)
-{
- return 0;
-}
-
-static inline struct mem_cgroup *mem_cgroup_from_id(unsigned short id)
-{
- WARN_ON_ONCE(id);
- /* XXX: This should always return root_mem_cgroup */
- return NULL;
-}
-
static inline unsigned short mem_cgroup_private_id(struct mem_cgroup *memcg)
{
return 0;
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 1ff2f9bd820c..ede39dde05df 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3615,11 +3615,6 @@ struct mem_cgroup *mem_cgroup_from_private_id(unsigned short id)
return xa_load(&mem_cgroup_private_ids, id);
}

-struct mem_cgroup *mem_cgroup_from_id(unsigned short id)
-{
- return mem_cgroup_from_private_id(id);
-}
-
struct mem_cgroup *mem_cgroup_get_from_ino(u64 ino)
{
struct cgroup *cgrp;
--
2.47.3