Re: [PATCH] mm: memcontrol: Fix do not put the css reference

From: Michal Hocko
Date: Mon Jun 15 2020 - 07:50:14 EST


On Sun 14-06-20 20:26:53, Muchun Song wrote:
> We should put the css reference when memory allocation failed.
>
> Fixes: f0a3a24b532d ("mm: memcg/slab: rework non-root kmem_cache lifecycle management")
> Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>

This looks like a stable tree material to me.

Acked-by: Michal Hocko <mhocko@xxxxxxxx>

> ---
> mm/memcontrol.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index 0b38b6ad547d..2323d811ee8e 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -2772,8 +2772,10 @@ static void memcg_schedule_kmem_cache_create(struct mem_cgroup *memcg,
> return;
>
> cw = kmalloc(sizeof(*cw), GFP_NOWAIT | __GFP_NOWARN);
> - if (!cw)
> + if (!cw) {
> + css_put(&memcg->css);
> return;
> + }
>
> cw->memcg = memcg;
> cw->cachep = cachep;
> --
> 2.11.0

--
Michal Hocko
SUSE Labs