On 04.12.2019 22:16, Yang Shi wrote:
> Since commit 0a432dcbeb32edcd211a5d8f7847d0da7642a8b4 ("mm: shrinker:
> make shrinker not depend on memcg kmem"), shrinkers' idr is protected by
> CONFIG_MEMCG instead of CONFIG_MEMCG_KMEM, so it makes no sense to
> protect shrinker idr replace with CONFIG_MEMCG_KMEM.
>
> Cc: Kirill Tkhai <ktkhai@xxxxxxxxxxxxx>
> Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
> Cc: Michal Hocko <mhocko@xxxxxxxx>
> Cc: Shakeel Butt <shakeelb@xxxxxxxxxx>
> Cc: Roman Gushchin <guro@xxxxxx>
> Signed-off-by: Yang Shi <yang.shi@xxxxxxxxxxxxxxxxx>
It looks like that in CONFIG_SLOB case we do not even call some shrinkers
for subordinate mem cgroups (i.e., we don't call deferred_split_shrinker),
since they never become completely registered.
Fixes: 0a432dcbeb32edcd211a5d8f7847d0da7642a8b4 ("mm: shrinker: make shrinker not depend on memcg kmem")
Reviewed-by: Kirill Tkhai <ktkhai@xxxxxxxxxxxxx>
> ---
> mm/vmscan.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/mm/vmscan.c b/mm/vmscan.c
> index ee4eecc..e7f10c4 100644
> --- a/mm/vmscan.c
> +++ b/mm/vmscan.c
> @@ -422,7 +422,7 @@ void register_shrinker_prepared(struct shrinker *shrinker)
> {
> down_write(&shrinker_rwsem);
> list_add_tail(&shrinker->list, &shrinker_list);
> -#ifdef CONFIG_MEMCG_KMEM
> +#ifdef CONFIG_MEMCG
> if (shrinker->flags & SHRINKER_MEMCG_AWARE)
> idr_replace(&shrinker_idr, shrinker, shrinker->id);
> #endif
>
