[PATCH 1/5] mm/vmscan: put the redirtied MADV_FREE pages back to anonymous LRU list

From: Miaohe Lin <linmiaohe@huawei.com>
To: <akpm@linux-foundation.org>
Cc: <hannes@cmpxchg.org>, <vbabka@suse.cz>, <mhocko@suse.com>,
	<axboe@kernel.dk>, <iamjoonsoo.kim@lge.com>, <alexs@kernel.org>,
	<apopple@nvidia.com>, <willy@infradead.org>, <minchan@kernel.org>,
	<david@redhat.com>, <shli@fb.com>, <hillf.zj@alibaba-inc.com>,
	<linux-mm@kvack.org>, <linux-kernel@vger.kernel.org>,
	<linmiaohe@huawei.com>
Subject: [PATCH 1/5] mm/vmscan: put the redirtied MADV_FREE pages back to anonymous LRU list
Date: Sat, 10 Jul 2021 18:03:25 +0800	[thread overview]
Message-ID: <20210710100329.49174-2-linmiaohe@huawei.com> (raw)
In-Reply-To: <20210710100329.49174-1-linmiaohe@huawei.com>

If the MADV_FREE pages are redirtied before they could be reclaimed, put
the pages back to anonymous LRU list by setting SwapBacked flag and the
pages will be reclaimed in normal swapout way. Otherwise MADV_FREE pages
won't be reclaimed as expected.

Fixes: 802a3a92ad7a ("mm: reclaim MADV_FREE pages")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
---
 mm/vmscan.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/mm/vmscan.c b/mm/vmscan.c
index a7602f71ec04..6483fe0e2065 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1628,6 +1628,7 @@ static unsigned int shrink_page_list(struct list_head *page_list,
 			if (!page_ref_freeze(page, 1))
 				goto keep_locked;
 			if (PageDirty(page)) {
+				SetPageSwapBacked(page);
 				page_ref_unfreeze(page, 1);
 				goto keep_locked;
 			}
-- 
2.23.0

