[064/173] mm/memcg: revise the using condition of lock_page_lruvec function series

Commit Message

Andrew Morton Feb. 24, 2021, 8:03 p.m. UTC

From: Alex Shi <[e-mail]>
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/[e-mail]
Signed-off-by: Alex Shi <[e-mail]>
Acked-by: Hugh Dickins <[e-mail]>
Cc: Hugh Dickins <[e-mail]>
Cc: Johannes Weiner <[e-mail]>
Cc: Michal Hocko <[e-mail]>
Cc: Vladimir Davydov <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
---

 mm/memcontrol.c |    9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

Patch

--- 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)
 {