On Mon, 12 Aug 2019 16:37:54 -0700 Roman Gushchin <guro@xxxxxx> wrote: > Similar to vmstats, percpu caching of local vmevents leads to an > accumulation of errors on non-leaf levels. This happens because > some leftovers may remain in percpu caches, so that they are > never propagated up by the cgroup tree and just disappear into > nonexistence with on releasing of the memory cgroup. > > To fix this issue let's accumulate and propagate percpu vmevents > values before releasing the memory cgroup similar to what we're > doing with vmstats. > > Since on cpu hotplug we do flush percpu vmstats anyway, we can > iterate only over online cpus. > > Fixes: 42a300353577 ("mm: memcontrol: fix recursive statistics correctness & scalabilty") No cc:stable?