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]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id BACB1CCD184 for ; Fri, 17 Oct 2025 05:39:19 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 000818E0012; Fri, 17 Oct 2025 01:39:19 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id F19D58E0002; Fri, 17 Oct 2025 01:39:18 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id DE1108E0012; Fri, 17 Oct 2025 01:39:18 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id C73038E0002 for ; Fri, 17 Oct 2025 01:39:18 -0400 (EDT) Received: from smtpin08.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 74C9B11A48F for ; Fri, 17 Oct 2025 05:39:18 +0000 (UTC) X-FDA: 84006503196.08.8975976 Received: from mx0b-00069f02.pphosted.com (mx0b-00069f02.pphosted.com [205.220.177.32]) by imf01.hostedemail.com (Postfix) with ESMTP id 0789340005 for ; Fri, 17 Oct 2025 05:39:14 +0000 (UTC) Authentication-Results: imf01.hostedemail.com; dkim=pass header.d=oracle.com header.s=corp-2025-04-25 header.b="DEicWG/C"; dkim=pass header.d=oracle.onmicrosoft.com header.s=selector2-oracle-onmicrosoft-com header.b=YnlTUF0i; spf=pass (imf01.hostedemail.com: domain of harry.yoo@oracle.com designates 205.220.177.32 as permitted sender) smtp.mailfrom=harry.yoo@oracle.com; dmarc=pass (policy=reject) header.from=oracle.com; arc=pass ("microsoft.com:s=arcselector10001:i=1") ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1760679555; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=PurqZoOyAQqghDYRVO4dP8Ucrloq6RZpO+1oz9WadKk=; b=dWgq+rbbNmcu+DLr7DZ60NDSkoOp39IamvU+Qf1WnCVRKaUQ6BRv6le1jpLn66ySHoEOBv jV+1BwyvhQLhIG1k9ogowPN6qd/zDeeafYTfxZ8NC4WY8pr7nmquFk1h3DbHtTGG1j3NTG DVK9JL0QlXGwyMOzrt58WFpwnPt621A= ARC-Authentication-Results: i=2; imf01.hostedemail.com; dkim=pass header.d=oracle.com header.s=corp-2025-04-25 header.b="DEicWG/C"; dkim=pass header.d=oracle.onmicrosoft.com header.s=selector2-oracle-onmicrosoft-com header.b=YnlTUF0i; spf=pass (imf01.hostedemail.com: domain of harry.yoo@oracle.com designates 205.220.177.32 as permitted sender) smtp.mailfrom=harry.yoo@oracle.com; dmarc=pass (policy=reject) header.from=oracle.com; arc=pass ("microsoft.com:s=arcselector10001:i=1") ARC-Seal: i=2; s=arc-20220608; d=hostedemail.com; t=1760679555; a=rsa-sha256; cv=pass; b=iYEnQO0qttgs5dd2SAHmU0xtUfD5FXqeo8spiwKMhFQkeEh7QQ1wTO0ZpWB7y4OSIJgrRg vLfDgsU3rz3YoMdizvqdCGJm+Iytk3sJhiBJG0MR/hb6z/2QOYzLm//ie4lFe/8z9QcxP2 Yd4s5ELdOXDQfp4Hi2iYvyejxHXXRhg= Received: from pps.filterd (m0246631.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 59GLu99r032266; Fri, 17 Oct 2025 05:38:58 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=cc :content-type:date:from:in-reply-to:message-id:mime-version :references:subject:to; s=corp-2025-04-25; bh=PurqZoOyAQqghDYRVO 4dP8Ucrloq6RZpO+1oz9WadKk=; b=DEicWG/CpLXfE6TP8Mwg9yOtE9XS4guncy UDkFtUCWVsLzQdraaNBf8BuEos60yhUW0CdIF7BziMOldMl9iNW1/D81cp/ZNiYD 459vUl5dzH+53GdnUF36XCQ2dFU8g9OnHDeb77LzywhcW23eAvBfycIc1AjJkfQq snm/QM9+PU3U2ak6Gr3gXEKHFlWxDxinTwDlm9pXh5+JXvy83zpaqpUB1LL1kEVi Ea+cXS1CP5ENjZtvskC8x+Q/fYF5Nm4TfIBogeovtcG8Y/0xTkgzYaBeEKbFrt+3 Q6g1q85l8Vg8T+5GAFZMZVPM/2M6C9HvzfEa6pF3jgjMB1r1ealQ== Received: from iadpaimrmta01.imrmtpd1.prodappiadaev1.oraclevcn.com (iadpaimrmta01.appoci.oracle.com [130.35.100.223]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 49ra1qhby7-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 17 Oct 2025 05:38:58 +0000 (GMT) Received: from pps.filterd (iadpaimrmta01.imrmtpd1.prodappiadaev1.oraclevcn.com [127.0.0.1]) by iadpaimrmta01.imrmtpd1.prodappiadaev1.oraclevcn.com (8.18.1.2/8.18.1.2) with ESMTP id 59H45kV0025938; Fri, 17 Oct 2025 05:38:57 GMT Received: from dm5pr21cu001.outbound.protection.outlook.com (mail-centralusazon11011024.outbound.protection.outlook.com [52.101.62.24]) by iadpaimrmta01.imrmtpd1.prodappiadaev1.oraclevcn.com (PPS) with ESMTPS id 49qdpjn7xj-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 17 Oct 2025 05:38:57 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=RFCftijaUFoBMxTuPrKzaHtt3V6yzY3eylvGpdAeXU2vGCNRC7kRgf36GenEfv8knGc6SK2TPtszVmSySoU0Oa52wC0XfWydeYmmkCDDXirY0plyfnkMgS9TeZ9AE6cOd/8l953O929TcDlTGBGD5R0qaPjd2VhjjKt1xq+RI4eR1CvQkt8/nR9tFWJp4RmTWBzUw5Hy21QEUVMSRFFjtymBf7T145CUS/8N3QkfsIm9I5GUaSQHRzIfO5c7riNx/2rOyx2W/8XXZY0mueQy5ujWUtYvAAyiOtR1Q/uWLEiaEErszvIWB7c8/bQ+D130Q4slYfpq5zqpT/DRc0IaEA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=PurqZoOyAQqghDYRVO4dP8Ucrloq6RZpO+1oz9WadKk=; b=xQkXkbx603xOtwMnHCSX8KsarW26tTM3pbdUNe4N8oYfAU5sqpznb9HhfS+NVTYrCUUWfS/XoYibLK3zCfLgp8bDQ86ibVfx913O7ViqCgUMQEhE70t2zxjTvHoO8ULYYND20otPf+OzSnmL/EpGT/HSXH8y3Jg8U1yVnLvAzhJA2jApatZqlCcD3fnTYIqTY9WvWU82lIJGIauIOhQzLeSrnng/2CgWjl2sb87pcqqVigfLwBNe3wCIrXTXoMhmb2lNBaUdyZh2SDVGPlDj5FjFOGpyUefPw5B2aA9RoDBnf3M2sghwiK7RqUZNe2x3euW+CowrDf7F87n4KpjAVg== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=oracle.com; dmarc=pass action=none header.from=oracle.com; dkim=pass header.d=oracle.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.onmicrosoft.com; s=selector2-oracle-onmicrosoft-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=PurqZoOyAQqghDYRVO4dP8Ucrloq6RZpO+1oz9WadKk=; b=YnlTUF0i83dZmrrpAWEWmF3SAekvo1osD6Cx8YBMPUdvq5S8BRrpZqE25RGj+92MVGa1rW2VCWJPp54xuRaUoS68VPMKCdmDRctE3UFKnkZSVprU5oBkuhkf/P9wIXaItpfsIb2HjVIffLZIz8m6VXw1F0pYzU+3yYA360nVFb0= Received: from CH3PR10MB7329.namprd10.prod.outlook.com (2603:10b6:610:12c::16) by CO1PR10MB4403.namprd10.prod.outlook.com (2603:10b6:303:9a::17) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9228.13; Fri, 17 Oct 2025 05:38:43 +0000 Received: from CH3PR10MB7329.namprd10.prod.outlook.com ([fe80::c2a4:fdda:f0c2:6f71]) by CH3PR10MB7329.namprd10.prod.outlook.com ([fe80::c2a4:fdda:f0c2:6f71%4]) with mapi id 15.20.9228.009; Fri, 17 Oct 2025 05:38:43 +0000 Date: Fri, 17 Oct 2025 14:38:31 +0900 From: Harry Yoo To: Qi Zheng Cc: hannes@cmpxchg.org, hughd@google.com, mhocko@suse.com, roman.gushchin@linux.dev, shakeel.butt@linux.dev, muchun.song@linux.dev, david@redhat.com, lorenzo.stoakes@oracle.com, ziy@nvidia.com, baolin.wang@linux.alibaba.com, Liam.Howlett@oracle.com, npache@redhat.com, ryan.roberts@arm.com, dev.jain@arm.com, baohua@kernel.org, lance.yang@linux.dev, akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, Muchun Song , Qi Zheng Subject: Re: [PATCH v5 3/4] mm: thp: use folio_batch to handle THP splitting in deferred_split_scan() Message-ID: References: <4f5d7a321c72dfe65e0e19a3f89180d5988eae2e.1760509767.git.zhengqi.arch@bytedance.com> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4f5d7a321c72dfe65e0e19a3f89180d5988eae2e.1760509767.git.zhengqi.arch@bytedance.com> X-ClientProxiedBy: SL2PR01CA0023.apcprd01.prod.exchangelabs.com (2603:1096:100:41::35) To CH3PR10MB7329.namprd10.prod.outlook.com (2603:10b6:610:12c::16) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: CH3PR10MB7329:EE_|CO1PR10MB4403:EE_ X-MS-Office365-Filtering-Correlation-Id: d90317f9-3281-4786-ecd0-08de0d3f6ebf X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|366016|7416014|376014|1800799024; X-Microsoft-Antispam-Message-Info: =?us-ascii?Q?QwYEVWTK1waOou161+bmnZSJ+cWzpOc5T2iTk3ftEeYPkCuxQU19zGCKoOCa?= =?us-ascii?Q?nc9Prf6KlK/yM5fUWWZPeNCobY5G6I7Ogm03Ujnvh45LbgyEyM51dIhe1vIa?= =?us-ascii?Q?h0IUqVRBd3+j6e8coBtsHVAEXeJ6LU5D6GvgLotA7TgLMpk5CaiPt0slgdc3?= =?us-ascii?Q?UHlMWJsERKbq92av27vS4Me/mSaAXzu/cQhhj3KUx0SBmpGJef8FIrjKcC6l?= =?us-ascii?Q?63iMzneIdajNkcrC4X02gzUrmUEVQtbEOgJHgQjoPrqxtC+xkHByquDaNpM3?= =?us-ascii?Q?vIS2CUcbnh7IQte+M7VKDZ1wcpBOTFIZWi26Ue/vlfpY3HQUVvqqljGpp9BO?= =?us-ascii?Q?Sv4/GAzDqVG/hsh8j3+Hgh4ATjj6KFMX5vn9JKOX5XQIHRu+/l4CUtb+39zX?= =?us-ascii?Q?FtVDOhIRUqTRJhiYhq0I4kgJdBUjV7f8h16o6CMTSlwHMX3Hx56KA9zQgMdy?= =?us-ascii?Q?4E9lrQUVaS/naEyob/XA69vvPMl6wfH6wHr87OLpYbFmLnY3WeKc7n+exWEo?= =?us-ascii?Q?E3HZ2ieemB5zfkGNMI7w7HgV4CXWAlOJaZreV34wMqrejy45DmuJBHtirVnB?= =?us-ascii?Q?Y6jgmDY+PFlJw8WY35tnouwbNQDgIc/9nvuRxbsxzHdjcXr03ym+8C2Buvs0?= =?us-ascii?Q?fKu/zET2ZNHt9h8pUKOi419VMZe991tHaj1RxlxcWRhP+p4Ot7GLocLk2AMV?= =?us-ascii?Q?PRYUFM3F2RgDK4rfbNPH4co0H8Vpqe92dPc6KoeGphoOlZTg6ji06EJ7eBNM?= =?us-ascii?Q?xg5ImObxExiQQqnPhGPJ6WKNu8CVminCEaw4X3uPpFphHhcIKHtY3TjKry+d?= =?us-ascii?Q?CoUBd9pyhBif4JH9hxAMo5/pdei8Oq2vJzhlp72i3jpwa8Pa0o5MVkECh9y1?= =?us-ascii?Q?UBFY4hxXryi6Yn+fMfhP4WwWClYIPXsE8JPR+oz3uNW1MpTFB3m50AgeXC4h?= =?us-ascii?Q?avkQF98lXAPwHU7nNrMblDF9tSE3hJu7gy2EAL81VXMwawBr8vRIJimgI6LT?= =?us-ascii?Q?Fjco2wl1y2GsESKsgbqvRrv3NW1OEJWL2Zjlo6skSkTIZMJ+QXvVUQdSYbAW?= =?us-ascii?Q?aOhU4VxPeKfchhfUNbAgvJmQ4wjntyaL7FgWjRy1Sj1gLhfP8sS5iVV9sGiN?= =?us-ascii?Q?TiQz8VrVsBrxfdTpmELAgAUaEjwAgNbbLUhqp3lHBOqIRfq1i//jxmbWhabq?= =?us-ascii?Q?C4LQ8zCsY7Yf+572FnMvrro4pcbZuEh0JEZV36h9ctkkSawKJ2T3BpnhQjfs?= =?us-ascii?Q?mnAQcLggE7JtRHQUIyOlJ1Jhzlah6faas4eY513/6Cv60B3erfoT7CSc+d7p?= =?us-ascii?Q?696EtNeqwLABOnHuIRlFjrR5pckQcVMr03u2zVxDvFObjR8aKbIWFRAr+4ZY?= =?us-ascii?Q?t0U9eHNUvAkinb/qCTxAd8OKOE2g6rzkfPUVHfOAEXrBf9QVcL0/+KsKKLu5?= =?us-ascii?Q?qlDqg2Dlh+nQu/NnMRTC/GPwxZgosb+4?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:CH3PR10MB7329.namprd10.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(366016)(7416014)(376014)(1800799024);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?MxgZqdWMz/Hxw+Y11L1kguVI3A10ZiXjaoh84Ae/hAVBzW7z78c2hva73Hd/?= =?us-ascii?Q?xPgk9WfwnEhctG5HLjAirCF1W+4CEaX/VaeqagZ7VQ2CqaIej/KKe2aabOff?= =?us-ascii?Q?YpnCpZ1/mn1Cz6r+zDjZoLmas/Es7gxjiACiG2PytncttVVBexYUv1fOdtz7?= =?us-ascii?Q?FRsbd8vMb/OFUeIdi6jX3a3FVDwGRIEv/bJAjdEHoN63a6KqIGzcONlAXFVn?= =?us-ascii?Q?GX5PK9JXAPnKaBU01zUQ5plgRFBGHsS/JG+6uLxqauNmqZf1CCy1MRaAuB7a?= =?us-ascii?Q?8rTcbt0wBSOZwcw0EIBMwnXCZMZ9758/4C5EW+kUspg0NEcpTeg0kCHhP4zy?= =?us-ascii?Q?CnGCgxFqYBPTknq2tdSgK5YMqFuqT71OPpWFcfbJ1qWZemBKyToyhj2abNmi?= =?us-ascii?Q?Jos2K4aPvAYVhsS0XUu1GbDaFkK/xzGN/k9s6rboJrffgjILIRZ2XZEH9qLi?= =?us-ascii?Q?zQHcFhemNA/GU56hgxqYwGAcyVofobbT96eWfcXBgvzRA3OyeMeDJV6R/tL0?= =?us-ascii?Q?X02H96iSEX+VInZF1uXv/dfOUYXPlIQ1QTYRYlZ2wo7uVbA7oCgZazoExvOm?= =?us-ascii?Q?obadnZrcMuqi/PYxctSuMc7hsR1vXGZ9loNOcpkvnoeZvx8jNX32tCJRf9Ct?= =?us-ascii?Q?K7k+oUem7dZehK1WT7vdRh9EtMzAWb09CuBgOFn2OhOY5/DQ938a/Fd3q+rX?= =?us-ascii?Q?OX7dCAn36KqtpAmWt5U+dqZTvyJ6gIgV6nHJHa0EAKO7VJ234cygZleBmVhu?= =?us-ascii?Q?NCXLRkqgkF5wTPswKG4OcvC/DUqBrdWdEcpr3CB/T65I5JQGz+hf3ZH12sAU?= =?us-ascii?Q?74bAowyOOQ8l85AR6/XJPiBiYey65+Movdg/SbvHPfzr1GDoyVokKHTrf41D?= =?us-ascii?Q?zsRLGe+ukyuFAJtJggZV5tCAwoNCsgTOqaeK1am/JNW0InTEKeOxgHS55hHX?= =?us-ascii?Q?N3G4YQ1WUnInPSbuGYGDPxQzGf0mNlcAnSwLlFPEBNjRom49SqQ12cnzUoHd?= =?us-ascii?Q?Bje9zgQ+3VJYn4iS4ilZdNp8shRMiRP6VOfHoLVIhhIeCm12DOOOQChZYOAz?= =?us-ascii?Q?Un/0Jb41nTuNyIAhH6cGlJ15XHRdWg7ISmCcoJcsBeneFzcCDAm0EZ64COyu?= =?us-ascii?Q?8tc1sQvfqS1zu6oIfPx6YvzImPflTMjdrSYAoMwxAiEajxXR57gWgTgqUb2W?= =?us-ascii?Q?dHTIa+YMzhQC2wVdVoD1df57441jgeWAF6hphu34fTaS0abfOXuBTx4Y6fXT?= =?us-ascii?Q?mCwvVJZZx5zHGvnbzR/1r7mpbjXrKU4YBNTIXUJ/c85oOn7S97bzlLcNqONZ?= =?us-ascii?Q?g9ry3hy+OSm7dhyoViLa+6n8IgXnLBtP5bzQu5GE9c8kPv+HCgLgpTT2mb/s?= =?us-ascii?Q?qxs1lOMqYPX2SSpcj811LlQAixhkkzOdNJXlxCm3t6kA1rhpFTcSYhLv+C5X?= =?us-ascii?Q?rfjWmRfFt+SFMMXOYiHWyiurw1kQuOquS/nDB/jWsjauPbv63Ae2sBa7zo/H?= =?us-ascii?Q?k/WX40KY9AsrlqpZvVhEW4Fk+ds40/bpoV6vJMYgsnY9lsdbpxGu612IwwgA?= =?us-ascii?Q?EDmxG6wkaZxiZ8Dgr5Q79nlo2DpXhgTt1JlSBTvP?= X-MS-Exchange-AntiSpam-ExternalHop-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-ExternalHop-MessageData-0: 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 X-OriginatorOrg: oracle.com X-MS-Exchange-CrossTenant-Network-Message-Id: d90317f9-3281-4786-ecd0-08de0d3f6ebf X-MS-Exchange-CrossTenant-AuthSource: CH3PR10MB7329.namprd10.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 17 Oct 2025 05:38:42.9369 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 4e2c6054-71cb-48f1-bd6c-3a9705aca71b X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: 9ua16FMMcqCHFw/XlERLUlnw7mu0I756dTWcPk2E3XH3NCd+I1cd5qkH+qkRdJve37/jgfcXdqQx2bnUnxnNBA== X-MS-Exchange-Transport-CrossTenantHeadersStamped: CO1PR10MB4403 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1121,Hydra:6.1.9,FMLib:17.12.80.40 definitions=2025-10-17_03,2025-10-13_01,2025-03-28_01 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 adultscore=0 mlxlogscore=999 malwarescore=0 mlxscore=0 spamscore=0 suspectscore=0 phishscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2510020000 definitions=main-2510170041 X-Proofpoint-Spam-Details-Enc: AW1haW4tMjUxMDEyMDA1MSBTYWx0ZWRfX7dAAIvR0hDH1 SYMwpJUpF/4j0M9I4M3ZEf1HLE7jebA63vovvT2zIVL1NlI9dBEQygrq/HQ4bc/SdbPMVuzIF7Q ETjNQWCWCmA4muSKINJIbQxIbSgGubn1rSPOKe+qjfB2YkmLSaNCmfh0zpLj9rdH5zncVxkGKEG YdCwl4gPqXH+5uSwfiUz/d8SwESUiA3XkgSNrW+0/GDVVG+35/LFsmUW6ZKUka17EK/i5KOzGTR ctzq4VHLKpnOBsCPWmTWEHgIDjOzHHyJ70bGDs1vTfDs56Ol3FdBHLSHOwHkczO9FmTtdfEEFXr TZAnjjr12eSckF8iXC0x2sSfZpi4SG3OlEXEt/sGtRPgchWBCxhoUHVzLuZ098kGHsg5RunBn+5 evZuixss0os7cduTHlFaqUti1ax2Y5IPbR59D/U78FrYOL9cQIM= X-Proofpoint-GUID: xtuBFYmlBfGorEwO3oaH0XoBYFEuIXax X-Proofpoint-ORIG-GUID: xtuBFYmlBfGorEwO3oaH0XoBYFEuIXax X-Authority-Analysis: v=2.4 cv=GL0F0+NK c=1 sm=1 tr=0 ts=68f1d672 b=1 cx=c_pps a=zPCbziy225d3KhSqZt3L1A==:117 a=zPCbziy225d3KhSqZt3L1A==:17 a=6eWqkTHjU83fiwn7nKZWdM+Sl24=:19 a=z/mQ4Ysz8XfWz/Q5cLBRGdckG28=:19 a=lCpzRmAYbLLaTzLvsPZ7Mbvzbb8=:19 a=xqWC_Br6kY4A:10 a=kj9zAlcOel0A:10 a=x6icFKpwvdMA:10 a=GoEa3M9JfhUA:10 a=VkNPw1HP01LnGYTKEx00:22 a=968KyxNXAAAA:8 a=Ikd4Dj_1AAAA:8 a=20KFwNOVAAAA:8 a=yPCof4ZbAAAA:8 a=wjPibnQ-TMmD0LTstD8A:9 a=CjuIK1q_8ugA:10 cc=ntf awl=host:12091 X-Stat-Signature: t7fbh1j4hjgr6bxoqe9outucmoywoc1p X-Rspam-User: X-Rspamd-Server: rspam07 X-Rspamd-Queue-Id: 0789340005 X-HE-Tag: 1760679554-827001 X-HE-Meta: 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 vYXe/YX4 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 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: List-Subscribe: List-Unsubscribe: On Wed, Oct 15, 2025 at 02:35:32PM +0800, Qi Zheng wrote: > From: Muchun Song > > The maintenance of the folio->_deferred_list is intricate because it's > reused in a local list. > > Here are some peculiarities: > > 1) When a folio is removed from its split queue and added to a local > on-stack list in deferred_split_scan(), the ->split_queue_len isn't > updated, leading to an inconsistency between it and the actual > number of folios in the split queue. > > 2) When the folio is split via split_folio() later, it's removed from > the local list while holding the split queue lock. At this time, > the lock is not needed as it is not protecting anything. > > 3) To handle the race condition with a third-party freeing or migrating > the preceding folio, we must ensure there's always one safe (with > raised refcount) folio before by delaying its folio_put(). More > details can be found in commit e66f3185fa04 ("mm/thp: fix deferred > split queue not partially_mapped"). It's rather tricky. > > We can use the folio_batch infrastructure to handle this clearly. In this > case, ->split_queue_len will be consistent with the real number of folios > in the split queue. If list_empty(&folio->_deferred_list) returns false, > it's clear the folio must be in its split queue (not in a local list > anymore). > > In the future, we will reparent LRU folios during memcg offline to > eliminate dying memory cgroups, which requires reparenting the split queue > to its parent first. So this patch prepares for using > folio_split_queue_lock_irqsave() as the memcg may change then. > > Signed-off-by: Muchun Song > Signed-off-by: Qi Zheng > Reviewed-by: Zi Yan > Acked-by: David Hildenbrand > Acked-by: Shakeel Butt > --- Nothing unusual came up during my review, so: Reviewed-by: Harry Yoo -- Cheers, Harry / Hyeonggon