mm: memcontrol: directly access page->memcg_data in mm/page_alloc.c

page_memcg() is not suitable for use by page_expected_state() and
page_bad_reason().  Because it can BUG_ON() for the slab pages when
CONFIG_DEBUG_VM is enabled.  As neither lru, nor kmem, nor slab page
should have anything left in there by the time the page is freed, what
we care about is whether the value of page->memcg_data is 0.  So just
directly access page->memcg_data here.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Muchun Song <[email protected]>
Acked-by: Johannes Weiner <[email protected]>
Reviewed-by: Shakeel Butt <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Roman Gushchin <[email protected]>
Cc: Vladimir Davydov <[email protected]>
Cc: Xiongchun Duan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

1 files changed, 2 insertions, 2 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index e2f19bf948db..56a8103580d6 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1103,7 +1103,7 @@ static inline bool page_expected_state(struct page *page,
 	if (unlikely((unsigned long)page->mapping |
 			page_ref_count(page) |
 #ifdef CONFIG_MEMCG
-			(unsigned long)page_memcg(page) |
+			page->memcg_data |
 #endif
 			(page->flags & check_flags)))
 		return false;
@@ -1128,7 +1128,7 @@ static const char *page_bad_reason(struct page *page, unsigned long flags)
 			bad_reason = "PAGE_FLAGS_CHECK_AT_FREE flag(s) set";
 	}
 #ifdef CONFIG_MEMCG
-	if (unlikely(page_memcg(page)))
+	if (unlikely(page->memcg_data))
 		bad_reason = "page still charged to cgroup";
 #endif
 	return bad_reason;