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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1F8DAC433EF for ; Mon, 25 Apr 2022 11:12:15 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id A44EF6B0075; Mon, 25 Apr 2022 07:12:13 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 9F5146B0078; Mon, 25 Apr 2022 07:12:13 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 86FDC6B0075; Mon, 25 Apr 2022 07:12:13 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.a.hostedemail.com [64.99.140.24]) by kanga.kvack.org (Postfix) with ESMTP id 6653D6B0078 for ; Mon, 25 Apr 2022 07:12:13 -0400 (EDT) Received: from smtpin31.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 34AB322E95 for ; Mon, 25 Apr 2022 11:12:13 +0000 (UTC) X-FDA: 79395137346.31.782D528 Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [45.249.212.189]) by imf18.hostedemail.com (Postfix) with ESMTP id B54291C003C for ; Mon, 25 Apr 2022 11:12:08 +0000 (UTC) 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: 8bit Content-Type: text/plain 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 X-Stat-Signature: dx84j95cmtwtn5sqgm6oh76dtin156s6 X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: B54291C003C Authentication-Results: imf18.hostedemail.com; dkim=none; spf=pass (imf18.hostedemail.com: domain of linmiaohe@huawei.com designates 45.249.212.189 as permitted sender) smtp.mailfrom=linmiaohe@huawei.com; dmarc=pass (policy=quarantine) header.from=huawei.com X-Rspam-User: X-HE-Tag: 1650885128-465764 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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