Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
From:   Muchun Song <songmuchun@bytedance.com>
To:     hannes@cmpxchg.org, mhocko@kernel.org, vdavydov.dev@gmail.com,
        akpm@linux-foundation.org
Cc:     cgroups@vger.kernel.org, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org,
        Muchun Song <songmuchun@bytedance.com>
Subject: [PATCH] mm: memcontrol: replace the loop with a list_for_each_entry()
Date:   Thu,  4 Feb 2021 18:53:20 +0800
Message-Id: <20210204105320.46072-1-songmuchun@bytedance.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

The rule of list walk has gone since:

 commit a9d5adeeb4b2 ("mm/memcontrol: allow to uncharge page without using page->lru field")

So remove the strange comment and replace the loop with a
list_for_each_entry().

Signed-off-by: Muchun Song <songmuchun@bytedance.com>
---
 mm/memcontrol.c | 17 ++---------------
 1 file changed, 2 insertions(+), 15 deletions(-)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 6c7f1ea3955e..43341bd7ea1c 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -6891,24 +6891,11 @@ static void uncharge_page(struct page *page, struct uncharge_gather *ug)
 static void uncharge_list(struct list_head *page_list)
 {
 	struct uncharge_gather ug;
-	struct list_head *next;
+	struct page *page;
 
 	uncharge_gather_clear(&ug);
-
-	/*
-	 * Note that the list can be a single page->lru; hence the
-	 * do-while loop instead of a simple list_for_each_entry().
-	 */
-	next = page_list->next;
-	do {
-		struct page *page;
-
-		page = list_entry(next, struct page, lru);
-		next = page->lru.next;
-
+	list_for_each_entry(page, page_list, lru)
 		uncharge_page(page, &ug);
-	} while (next != page_list);
-
 	uncharge_batch(&ug);
 }
 
-- 
2.11.0