On Sun, Dec 06, 2020 at 06:14:40PM +0800, Muchun Song wrote: > The unit of NR_ANON_THPS is HPAGE_PMD_NR already. So it should inc/dec > by one rather than nr_pages. This is a real bug, thanks for catching it. However, your patch changes the user-visible output of /proc/vmstat! NR_ANON_THPS isn't just used by memcg, it's a generic accounting item of the memory subsystem. See this from the Fixes:-patch: - __inc_node_page_state(page, NR_ANON_THPS); + __inc_lruvec_page_state(page, NR_ANON_THPS); While we've considered /proc/vmstat less official than other files like meminfo, and have in the past freely added and removed items, changing the unit of an existing one is not going to work.