[PATCH] memcg: Add comment to mem_cgroup_css_online()
From: Kirill Tkhai <hidden>
Date: 2018-08-02 08:13:37
Also in:
linux-mm, lkml
Subsystem:
control group - memory resource controller (memcg), memory management, the rest · Maintainers:
Johannes Weiner, Michal Hocko, Roman Gushchin, Shakeel Butt, Andrew Morton, Linus Torvalds
Explain relationships between allocation and expanding. Suggested-by: Vladimir Davydov <redacted> Signed-off-by: Kirill Tkhai <redacted> ---
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index d90993ef1d7d..34e5ff72ce87 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c@@ -4703,6 +4703,11 @@ static int mem_cgroup_css_online(struct cgroup_subsys_state *css) { struct mem_cgroup *memcg = mem_cgroup_from_css(css); + /* + * A memcg must be visible for memcg_expand_shrinker_maps() + * by the time the maps are allocated. So, we allocate maps + * here, when for_each_mem_cgroup() can't skip it. + */ if (memcg_alloc_shrinker_maps(memcg)) { mem_cgroup_id_remove(memcg); return -ENOMEM;