Michal Hocko writes:
and it makes some sense. Except for the root memcg where we do not account any memory. Adding if (mem_cgroup_is_root(memcg)) return false; should do the trick. The same is the case for mem_cgroup_below_low. Could you give it a try please just to confirm?
Oh, of course :-) This seems more likely than what I proposed, and would be great to test.