From: Minchan Kim <minchan@kernel.org>
To: Andrew Morton <akpm@linux-foundation.org>
CC: <linux-kernel@vger.kernel.org>, <linux-mm@kvack.org>,
        <kernel-team@lge.com>, Johannes Weiner <hannes@cmpxchg.org>,
        Michal Hocko <mhocko@suse.com>,
        "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
        Anshuman Khandual <khandual@linux.vnet.ibm.com>,
        Minchan Kim <minchan@kernel.org>
Subject: [PATCH v1 03/10] mm: remove SWAP_MLOCK check for SWAP_SUCCESS in ttu
Date: Mon, 13 Mar 2017 09:35:46 +0900
Message-ID: <1489365353-28205-4-git-send-email-minchan@kernel.org>
In-Reply-To: <1489365353-28205-1-git-send-email-minchan@kernel.org>
References: <1489365353-28205-1-git-send-email-minchan@kernel.org>
MIME-Version: 1.0
Content-Type: text/plain
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 680
Lines: 25

If the page is mapped and rescue in try_to_unmap_one,
page_mapcount(page) == 0 cannot be true so page_mapcount check
in try_to_unmap is enough to return SWAP_SUCCESS.
IOW, SWAP_MLOCK check is redundant so remove it.

Signed-off-by: Minchan Kim <minchan@kernel.org>
---
 mm/rmap.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/rmap.c b/mm/rmap.c
index d47af09..1cfb3a3 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1530,7 +1530,7 @@ int try_to_unmap(struct page *page, enum ttu_flags flags)
 	else
 		ret = rmap_walk(page, &rwc);
 
-	if (ret != SWAP_MLOCK && !page_mapcount(page))
+	if (!page_mapcount(page))
 		ret = SWAP_SUCCESS;
 	return ret;
 }
-- 
2.7.4