linux-kernel - [PATCH 11/16] mm/migration: remove unneeded lock page and PageMovable check

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Message-ID: <20220304093409.25829-12-linmiaohe@huawei.com>
Date:   Fri, 4 Mar 2022 17:34:04 +0800
From:   Miaohe Lin <linmiaohe@...wei.com>
To:     <akpm@...ux-foundation.org>
CC:     <mike.kravetz@...cle.com>, <shy828301@...il.com>,
        <willy@...radead.org>, <ying.huang@...el.com>, <ziy@...dia.com>,
        <minchan@...nel.org>, <apopple@...dia.com>,
        <ave.hansen@...ux.intel.com>, <o451686892@...il.com>,
        <almasrymina@...gle.com>, <jhubbard@...dia.com>,
        <rcampbell@...dia.com>, <peterx@...hat.com>,
        <naoya.horiguchi@....com>, <mhocko@...e.com>, <riel@...hat.com>,
        <linux-mm@...ck.org>, <linux-kernel@...r.kernel.org>,
        <linmiaohe@...wei.com>
Subject: [PATCH 11/16] 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 soon. So we can thus remove unneeded lock page and
PageMovable check here.

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

diff --git a/mm/migrate.c b/mm/migrate.c
index 1de5289a4af0..e0db06927f02 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1074,12 +1074,8 @@ 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