From 4f0c9c68a0b15b914b24c20d33f80ed0cf2df9d9 Mon Sep 17 00:00:00 2001
From: Yang Shi <yang.shi@linux.alibaba.com>
Date: Mon, 23 Sep 2019 15:38:09 -0700
Subject: [PATCH] mm: move mem_cgroup_uncharge out of __page_cache_release()

References: git fixes (mm/memcontrol)
Patch-mainline: v5.4-rc1
Git-commit: 7ae88534cdd96235cd775c03b32a75009355740b

A later patch makes THP deferred split shrinker memcg aware, but it needs
page->mem_cgroup information in THP destructor, which is called after
mem_cgroup_uncharge() now.

So move mem_cgroup_uncharge() from __page_cache_release() to compound page
destructor, which is called by both THP and other compound pages except
HugeTLB.  And call it in __put_single_page() for single order page.

Link: http://lkml.kernel.org/r/1565144277-36240-3-git-send-email-yang.shi@linux.alibaba.com
Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
Suggested-by: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
---
 mm/page_alloc.c | 1 +
 mm/swap.c       | 2 +-
 mm/vmscan.c     | 6 ++----
 3 files changed, 4 insertions(+), 5 deletions(-)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 47338f00f994..e420a4a178bd 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -670,6 +670,7 @@ static void bad_page(struct page *page, const char *reason,
 
 void free_compound_page(struct page *page)
 {
+	mem_cgroup_uncharge(page);
 	__free_pages_ok(page, compound_order(page));
 }
 
diff --git a/mm/swap.c b/mm/swap.c
index 0226c5346560..784dc1620620 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -71,12 +71,12 @@ static void __page_cache_release(struct page *page)
 		spin_unlock_irqrestore(&pgdat->lru_lock, flags);
 	}
 	__ClearPageWaiters(page);
-	mem_cgroup_uncharge(page);
 }
 
 static void __put_single_page(struct page *page)
 {
 	__page_cache_release(page);
+	mem_cgroup_uncharge(page);
 	free_unref_page(page);
 }
 
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 0a6a3dfa81c3..7179e3734197 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1488,10 +1488,9 @@ static unsigned long shrink_page_list(struct list_head *page_list,
 		 * Is there need to periodically free_page_list? It would
 		 * appear not as the counts should be low
 		 */
-		if (unlikely(PageTransHuge(page))) {
-			mem_cgroup_uncharge(page);
+		if (unlikely(PageTransHuge(page)))
 			(*get_compound_page_dtor(page))(page);
-		} else
+		else
 			list_add(&page->lru, &free_pages);
 		continue;
 
@@ -1912,7 +1911,6 @@ static unsigned noinline_for_stack move_pages_to_lru(struct lruvec *lruvec,
 
 			if (unlikely(PageCompound(page))) {
 				spin_unlock_irq(&pgdat->lru_lock);
-				mem_cgroup_uncharge(page);
 				(*get_compound_page_dtor(page))(page);
 				spin_lock_irq(&pgdat->lru_lock);
 			} else