Re: [PATCH] memcg: make it work on sparse non-0-node systems

Michal Hocko
2019-04-29T11:30:28Z

On Mon 29-04-19 12:59:39, Jiri Slaby wrote:
[...]
> static inline bool list_lru_memcg_aware(struct list_lru *lru)
> {
> - /*
> - * This needs node 0 to be always present, even
> - * in the systems supporting sparse numa ids.
> - */
> - return !!lru->node[0].memcg_lrus;
> + return !!lru->node[first_online_node].memcg_lrus;
> }
>
> static inline struct list_lru_one *

How come this doesn't blow up later - e.g. in memcg_destroy_list_lru
path which does iterate over all existing nodes thus including the
node 0.
--
Michal Hocko
SUSE Labs