Explain relationships between allocation and expanding. Suggested-by: Vladimir Davydov <vdavydov.dev@xxxxxxxxx> Signed-off-by: Kirill Tkhai <ktkhai@xxxxxxxxxxxxx> --- 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; -- To unsubscribe from this list: send the line "unsubscribe cgroups" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html