From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5C4ECC433EF for ; Mon, 25 Apr 2022 11:12:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241700AbiDYLPs (ORCPT ); Mon, 25 Apr 2022 07:15:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45438 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241705AbiDYLPm (ORCPT ); Mon, 25 Apr 2022 07:15:42 -0400 Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [45.249.212.189]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A7C222A279 for ; Mon, 25 Apr 2022 04:12:11 -0700 (PDT) Received: from canpemm500002.china.huawei.com (unknown [172.30.72.54]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4Kn2Kk5yjbzCsKn; Mon, 25 Apr 2022 19:07:38 +0800 (CST) Received: from huawei.com (10.175.124.27) by canpemm500002.china.huawei.com (7.192.104.244) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Mon, 25 Apr 2022 19:12:09 +0800 From: Miaohe Lin To: CC: , , , , , , Subject: [PATCH v3 1/6] mm/vmscan: add a comment about MADV_FREE pages check in folio_check_dirty_writeback Date: Mon, 25 Apr 2022 19:12:27 +0800 Message-ID: <20220425111232.23182-2-linmiaohe@huawei.com> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20220425111232.23182-1-linmiaohe@huawei.com> References: <20220425111232.23182-1-linmiaohe@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-Originating-IP: [10.175.124.27] X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) To canpemm500002.china.huawei.com (7.192.104.244) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The MADV_FREE pages check in folio_check_dirty_writeback is a bit hard to follow. Add a comment to make the code clear. Suggested-by: Huang, Ying Signed-off-by: Miaohe Lin Reviewed-by: Christoph Hellwig Reviewed-by: Oscar Salvador --- mm/vmscan.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index 99a572f01cb4..913eb565140c 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -1438,7 +1438,10 @@ static void folio_check_dirty_writeback(struct folio *folio, /* * Anonymous pages are not handled by flushers and must be written - * from reclaim context. Do not stall reclaim based on them + * from reclaim context. Do not stall reclaim based on them. + * MADV_FREE anonymous pages are put into inactive file list too. + * They could be mistakenly treated as file lru. So further anon + * test is needed. */ if (!folio_is_file_lru(folio) || (folio_test_anon(folio) && !folio_test_swapbacked(folio))) { -- 2.23.0