From: Jaewon Kim <jaewon31.kim@samsung.com>
To: akpm@linux-foundation.org
Cc: mgorman@suse.de, minchan@kernel.org, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org, jaewon31.kim@gmail.com,
        Jaewon Kim <jaewon31.kim@samsung.com>
Subject: [PATCH v2] vmscan: fix increasing nr_isolated incurred by putback
 unevictable pages
Date: Tue, 04 Aug 2015 19:40:08 +0900
Message-id: <1438684808-12707-1-git-send-email-jaewon31.kim@samsung.com>
DLP-Filter: Pass
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1299
Lines: 38

reclaim_clean_pages_from_list() assumes that shrink_page_list() returns
number of pages removed from the candidate list. But shrink_page_list()
puts back mlocked pages without passing it to caller and without
counting as nr_reclaimed. This incurrs increasing nr_isolated.
To fix this, this patch changes shrink_page_list() to pass unevictable
pages back to caller. Caller will take care those pages.

Signed-off-by: Jaewon Kim <jaewon31.kim@samsung.com>
---
Changes since v1

1/ changed subject from vmscan: reclaim_clean_pages_from_list() must count mlocked pages
2/ changed to return unevictable pages rather than returning the number of unevictable pages

 mm/vmscan.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 5e8eadd..a4b2d07 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1157,7 +1157,7 @@ cull_mlocked:
 		if (PageSwapCache(page))
 			try_to_free_swap(page);
 		unlock_page(page);
-		putback_lru_page(page);
+		list_add(&page->lru, &ret_pages);
 		continue;
 
 activate_locked:
-- 
1.9.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/