On Mon, Aug 12, 2019 at 04:37:54PM -0700, Roman Gushchin 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. Just to clarify: this patch should be placed on top of two other patches, which I sent a bit earlier today: 1) mm: memcontrol: flush percpu slab vmstats on kmem offlining 2) mm: memcontrol: flush percpu vmstats before releasing memcg Sorry for the inconvenience, I forgot about vmevents during working on the final version, and remembered too late. Thanks!
