From 48060834f2277374bb68c04c62de8b57e769f701 Mon Sep 17 00:00:00 2001 From: Muchun Song Date: Thu, 29 Apr 2021 22:56:45 -0700 Subject: [PATCH] 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/20210319163821.20704-4-songmuchun@bytedance.com Signed-off-by: Muchun Song Acked-by: Johannes Weiner Reviewed-by: Shakeel Butt Cc: Michal Hocko Cc: Roman Gushchin Cc: Vladimir Davydov Cc: Xiongchun Duan Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_alloc.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index e2f19bf..56a8103 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; -- 2.7.4