Hi Roman, On Fri, Oct 25, 2019 at 04:27:10PM -0700, Roman Gushchin wrote: > page_cgroup_ino() doesn't return a valid memcg pointer for non-compund > slab pages, because it depends on PgHead AND PgSlab flags to be set > to determine the memory cgroup from the kmem_cache. > It's correct for compound pages, but not for generic small pages. Those > don't have PgHead set, so it ends up returning zero. > > Fix this by replacing the condition to PageSlab() && !PageTail(). You may also want to update the comment above memcg_from_slab_page(): * So this function assumes that the page can pass PageHead() and PageSlab() * checks.
