On Fri, Oct 01, 2021 at 03:09:37PM -0400, Waiman Long wrote:
> Since commit d648bcc7fe65 ("mm: kmem: make memcg_kmem_enabled()
> irreversible"), the only thing memcg_free_kmem() does is to call
> memcg_offline_kmem() when the memcg is still online. However,
> memcg_offline_kmem() is only called from mem_cgroup_css_free() which
> cannot be reached if the memcg hasn't been offlined first.
Hm, is it true? What if online_css() fails?
> As this
> function now serves no purpose, we should just remove it.
It looks like we can just use memcg_offline_kmem() instead of
memcg_free_kmem().
Thanks!
>
> Signed-off-by: Waiman Long <longman@xxxxxxxxxx>
> ---
> mm/memcontrol.c | 11 -----------
> 1 file changed, 11 deletions(-)
>
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index 4568363062c1..8177f253a127 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -3673,13 +3673,6 @@ static void memcg_offline_kmem(struct mem_cgroup *memcg)
>
> memcg_free_cache_id(kmemcg_id);
> }
> -
> -static void memcg_free_kmem(struct mem_cgroup *memcg)
> -{
> - /* css_alloc() failed, offlining didn't happen */
> - if (unlikely(memcg->kmem_state == KMEM_ONLINE))
> - memcg_offline_kmem(memcg);
> -}
> #else
> static int memcg_online_kmem(struct mem_cgroup *memcg)
> {
> @@ -3688,9 +3681,6 @@ static int memcg_online_kmem(struct mem_cgroup *memcg)
> static void memcg_offline_kmem(struct mem_cgroup *memcg)
> {
> }
> -static void memcg_free_kmem(struct mem_cgroup *memcg)
> -{
> -}
> #endif /* CONFIG_MEMCG_KMEM */
>
> static int memcg_update_kmem_max(struct mem_cgroup *memcg,
> @@ -5325,7 +5315,6 @@ static void mem_cgroup_css_free(struct cgroup_subsys_state *css)
> cancel_work_sync(&memcg->high_work);
> mem_cgroup_remove_from_trees(memcg);
> free_shrinker_info(memcg);
> - memcg_free_kmem(memcg);
> mem_cgroup_free(memcg);
> }
>
> --
> 2.18.1
>
