Re: [PATCH] mm: memcontrol: rename mem_cgroup_from_slab_obj()

[Anshuman Khandual <anshuman.khandual@arm.com>]

On 10/12/25 9:13 PM, Johannes Weiner wrote:
> In addition to slab objects, this function is used for resolving
> non-slab kernel pointers. This has caused confusion in recent
> refactoring work. Rename it to mem_cgroup_from_virt(), sticking with
> terminology established by the virt_to_<foo>() converters.
> 
> Link: https://lore.kernel.org/linux-mm/20251113161424.GB3465062@cmpxchg.org/
> Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
> ---
>  include/linux/memcontrol.h | 4 ++--
>  mm/list_lru.c              | 4 ++--
>  mm/memcontrol.c            | 4 ++--
>  3 files changed, 6 insertions(+), 6 deletions(-)
> 
> diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
> index 0651865a4564..17ad5cf43129 100644
> --- a/include/linux/memcontrol.h
> +++ b/include/linux/memcontrol.h
> @@ -1727,7 +1727,7 @@ static inline int memcg_kmem_id(struct mem_cgroup *memcg)
>  	return memcg ? memcg->kmemcg_id : -1;
>  }
>  
> -struct mem_cgroup *mem_cgroup_from_slab_obj(void *p);
> +struct mem_cgroup *mem_cgroup_from_virt(void *p);
>  
>  static inline void count_objcg_events(struct obj_cgroup *objcg,
>  				      enum vm_event_item idx,
> @@ -1799,7 +1799,7 @@ static inline int memcg_kmem_id(struct mem_cgroup *memcg)
>  	return -1;
>  }
>  
> -static inline struct mem_cgroup *mem_cgroup_from_slab_obj(void *p)
> +static inline struct mem_cgroup *mem_cgroup_from_virt(void *p)
>  {
>  	return NULL;
>  }
> diff --git a/mm/list_lru.c b/mm/list_lru.c
> index ec48b5dadf51..37b642f6cbda 100644
> --- a/mm/list_lru.c
> +++ b/mm/list_lru.c
> @@ -187,7 +187,7 @@ bool list_lru_add_obj(struct list_lru *lru, struct list_head *item)
>  
>  	if (list_lru_memcg_aware(lru)) {
>  		rcu_read_lock();
> -		ret = list_lru_add(lru, item, nid, mem_cgroup_from_slab_obj(item));
> +		ret = list_lru_add(lru, item, nid, mem_cgroup_from_virt(item));
>  		rcu_read_unlock();
>  	} else {
>  		ret = list_lru_add(lru, item, nid, NULL);
> @@ -224,7 +224,7 @@ bool list_lru_del_obj(struct list_lru *lru, struct list_head *item)
>  
>  	if (list_lru_memcg_aware(lru)) {
>  		rcu_read_lock();
> -		ret = list_lru_del(lru, item, nid, mem_cgroup_from_slab_obj(item));
> +		ret = list_lru_del(lru, item, nid, mem_cgroup_from_virt(item));
>  		rcu_read_unlock();
>  	} else {
>  		ret = list_lru_del(lru, item, nid, NULL);
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index be810c1fbfc3..e552072e346c 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -806,7 +806,7 @@ void mod_lruvec_kmem_state(void *p, enum node_stat_item idx, int val)
>  	struct lruvec *lruvec;
>  
>  	rcu_read_lock();
> -	memcg = mem_cgroup_from_slab_obj(p);
> +	memcg = mem_cgroup_from_virt(p);
>  
>  	/*
>  	 * Untracked pages have no memcg, no lruvec. Update only the
> @@ -2619,7 +2619,7 @@ struct mem_cgroup *mem_cgroup_from_obj_slab(struct slab *slab, void *p)
>   * The caller must ensure the memcg lifetime, e.g. by taking rcu_read_lock(),
>   * cgroup_mutex, etc.
>   */
> -struct mem_cgroup *mem_cgroup_from_slab_obj(void *p)
> +struct mem_cgroup *mem_cgroup_from_virt(void *p)
>  {
>  	struct slab *slab;
> 

Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>