Re: [PATCH] fix: mm: memcontrol: convert objcg to be per-memcg per-node type

[Usama Arif]

On 09/03/2026 14:29, Qi Zheng wrote:
> From: Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx>
> 
> Reset pn->orig_objcg to NULL to prevent obj_cgroup_put()
> from being called agagin in __mem_cgroup_free().
> 
> Reported-by: Usama Arif <usama.arif@xxxxxxxxx>
> Signed-off-by: Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx>
> ---
>  mm/memcontrol.c | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index 992a3f5caa62b..ad32639ea5959 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -4140,8 +4140,14 @@ static int mem_cgroup_css_online(struct cgroup_subsys_state *css)
>  	for_each_node(nid) {
>  		struct mem_cgroup_per_node *pn = memcg->nodeinfo[nid];
>  
> -		if (pn && pn->orig_objcg)
> +		if (pn && pn->orig_objcg) {
>  			obj_cgroup_put(pn->orig_objcg);
> +			/*
> +			 * Reset pn->orig_objcg to NULL to prevent obj_cgroup_put()
> +			 * from being called agagin in __mem_cgroup_free().

nit: s/agagin/again/

Apart from the nit.

Acked-by: Usama Arif <usama.arif@xxxxxxxxx>

> +			 */
> +			pn->orig_objcg = NULL;
> +		}
>  	}
>  	free_shrinker_info(memcg);
>  offline_kmem: