hugetlbfs pages do not participate in memcg: so although they do find most of migrate_page_states() useful, it would be better if they did not call into mem_cgroup_migrate() - where Qian Cai reported that LTP's move_pages12 triggers the warning in Alex Shi's prospective commit "mm/memcg: warning on !memcg after readahead page charged".
Signed-off-by: Hugh Dickins <[email protected]> --- This fixes a likely future warning, but is just a cleanup right now. mm/migrate.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- 5.9-rc2/mm/migrate.c 2020-08-16 17:32:50.665507048 -0700 +++ linux/mm/migrate.c 2020-08-28 17:42:07.967278385 -0700 @@ -668,7 +668,8 @@ void migrate_page_states(struct page *ne copy_page_owner(page, newpage); - mem_cgroup_migrate(page, newpage); + if (!PageHuge(page)) + mem_cgroup_migrate(page, newpage); } EXPORT_SYMBOL(migrate_page_states);
