On Wed 24-03-21 12:11:35, Muchun Song wrote: > On Tue, Mar 23, 2021 at 11:04 PM Muchun Song <[email protected]> wrote: > > > > The pages aren't accounted at the root level, so we cannot uncharge the > > page to the memsw counter for the root memcg. Fix this. > > > > Fixes: 1f47b61fb407 ("mm: memcontrol: fix swap counter leak on swapout from > > offline cgroup") > > Signed-off-by: Muchun Song <[email protected]> > > I am very sorry. I should repent. I suddenly realise the fix is totally > wrong. Because the @memcg cannot be root memcg when > @memcg != @swap_memcg.
I am probably blind but I do not see why this would be the case. We have memcg != swap_memcg in this branch but we do not know the neither of the two is root_mem_cgroup, no? If we did knot that we wouldn't have to check for swap_memcg != root_mem_cgroup. Or do I miss something? -- Michal Hocko SUSE Labs
