From: Alex Shi <alex.shi@xxxxxxxxxxxxxxxxx> Subject: mm/memcg: revise the using condition of lock_page_lruvec function series lock_page_lruvec() and its variants are safe to use under the same conditions as commit_charge(): add lock_page_memcg() to the comment. Polished with Hugh Dickins' suggestions, thanks! Link: https://lkml.kernel.org/r/1608614453-10739-1-git-send-email-alex.shi@xxxxxxxxxxxxxxxxx Signed-off-by: Alex Shi <alex.shi@xxxxxxxxxxxxxxxxx> Acked-by: Hugh Dickins <hughd@xxxxxxxxxx> Cc: Hugh Dickins <hughd@xxxxxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxxxx> Cc: Vladimir Davydov <vdavydov.dev@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/memcontrol.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) --- a/mm/memcontrol.c~mm-memcg-revise-the-using-condition-of-lock_page_lruvec-function-series +++ a/mm/memcontrol.c @@ -1346,10 +1346,11 @@ void lruvec_memcg_debug(struct lruvec *l * lock_page_lruvec - lock and return lruvec for a given page. * @page: the page * - * This series functions should be used in either conditions: - * PageLRU is cleared or unset - * or page->_refcount is zero - * or page is locked. + * These functions are safe to use under any of the following conditions: + * - page locked + * - PageLRU cleared + * - lock_page_memcg() + * - page->_refcount is zero */ struct lruvec *lock_page_lruvec(struct page *page) { _