linux-kernel - [PATCH v2 2/4] mm/migration: remove unneeded lock page and PageMovable check

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Message-ID: <20220425132723.34824-3-linmiaohe@huawei.com>
Date:   Mon, 25 Apr 2022 21:27:21 +0800
From:   Miaohe Lin <linmiaohe@...wei.com>
To:     <akpm@...ux-foundation.org>, <mike.kravetz@...cle.com>,
        <naoya.horiguchi@....com>
CC:     <ying.huang@...el.com>, <hch@....de>, <dhowells@...hat.com>,
        <cl@...ux.com>, <david@...hat.com>, <linux-mm@...ck.org>,
        <linux-kernel@...r.kernel.org>, <linmiaohe@...wei.com>
Subject: [PATCH v2 2/4] mm/migration: remove unneeded lock page and PageMovable check

When non-lru movable page was freed from under us, __ClearPageMovable must
have been done. Even if it's not done, ClearPageIsolated here won't hurt
as page will be freed anyway. So we can thus remove unneeded lock page and
PageMovable check here.

Signed-off-by: Miaohe Lin <linmiaohe@...wei.com>
Reviewed-by: Christoph Hellwig <hch@....de>
---
 mm/migrate.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/mm/migrate.c b/mm/migrate.c
index b779646665fe..0fc4651b3e39 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1093,12 +1093,8 @@ static int unmap_and_move(new_page_t get_new_page,
 		/* page was freed from under us. So we are done. */
 		ClearPageActive(page);
 		ClearPageUnevictable(page);
-		if (unlikely(__PageMovable(page))) {
-			lock_page(page);
-			if (!PageMovable(page))
-				ClearPageIsolated(page);
-			unlock_page(page);
-		}
+		if (unlikely(__PageMovable(page)))
+			ClearPageIsolated(page);
 		goto out;
 	}
 
-- 
2.23.0