Re: [PATCH 5/8] mm: memcontrol: separate kmem code from legacy tcp accounting code

Michal Hocko
2015-12-10T12:59:15Z

On Tue 08-12-15 13:34:22, Johannes Weiner wrote:
> The cgroup2 memory controller will include important in-kernel memory
> consumers per default, including socket memory, but it will no longer
> carry the historic tcp control interface.
>
> Separate the kmem state init from the tcp control interface init in
> preparation for that.
>
> Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>

Acked-by: Michal Hocko <mhocko@suse.com>

> ---
> mm/memcontrol.c | 33 ++++++++++++---------------------
> 1 file changed, 12 insertions(+), 21 deletions(-)
>
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index 5118618..55a3f07 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -2925,17 +2925,6 @@ static int memcg_propagate_kmem(struct mem_cgroup *memcg)
> return ret;
> }
>
> -static int memcg_init_kmem(struct mem_cgroup *memcg)
> -{
> - int ret;
> -
> - ret = memcg_propagate_kmem(memcg);
> - if (ret)
> - return ret;
> -
> - return tcp_init_cgroup(memcg);
> -}
> -
> static void memcg_offline_kmem(struct mem_cgroup *memcg)
> {
> struct cgroup_subsys_state *css;
> @@ -2988,7 +2977,6 @@ static void memcg_free_kmem(struct mem_cgroup *memcg)
> static_branch_dec(&memcg_kmem_enabled_key);
> WARN_ON(page_counter_read(&memcg->kmem));
> }
> - tcp_destroy_cgroup(memcg);
> }
> #else
> static int memcg_update_kmem_limit(struct mem_cgroup *memcg,
> @@ -2996,16 +2984,9 @@ static int memcg_update_kmem_limit(struct mem_cgroup *memcg,
> {
> return -EINVAL;
> }
> -static int memcg_init_kmem(struct mem_cgroup *memcg)
> -{
> - return 0;
> -}
> static void memcg_offline_kmem(struct mem_cgroup *memcg)
> {
> }
> -static void memcg_free_kmem(struct mem_cgroup *memcg)
> -{
> -}
> #endif /* CONFIG_MEMCG_KMEM */
>
> /*
> @@ -4241,9 +4222,14 @@ mem_cgroup_css_online(struct cgroup_subsys_state *css)
> }
> mutex_unlock(&memcg_create_mutex);
>
> - ret = memcg_init_kmem(memcg);
> +#ifdef CONFIG_MEMCG_KMEM
> + ret = memcg_propagate_kmem(memcg);
> if (ret)
> return ret;
> + ret = tcp_init_cgroup(memcg);
> + if (ret)
> + return ret;
> +#endif
>
> #ifdef CONFIG_INET
> if (cgroup_subsys_on_dfl(memory_cgrp_subsys) && !cgroup_memory_nosocket)
> @@ -4288,11 +4274,16 @@ static void mem_cgroup_css_free(struct cgroup_subsys_state *css)
> {
> struct mem_cgroup *memcg = mem_cgroup_from_css(css);
>
> - memcg_free_kmem(memcg);
> #ifdef CONFIG_INET
> if (cgroup_subsys_on_dfl(memory_cgrp_subsys) && !cgroup_memory_nosocket)
> static_branch_dec(&memcg_sockets_enabled_key);
> #endif
> +
> +#ifdef CONFIG_MEMCG_KMEM
> + memcg_free_kmem(memcg);
> + tcp_destroy_cgroup(memcg);
> +#endif
> +
> __mem_cgroup_free(memcg);
> }
>
> --
> 2.6.3

--
Michal Hocko
SUSE Labs