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 672C4C27C53 for ; Wed, 5 Jun 2024 14:09:54 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id ECE836B0089; Wed, 5 Jun 2024 10:09:53 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id E56DB6B008A; Wed, 5 Jun 2024 10:09:53 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id CA9986B008C; Wed, 5 Jun 2024 10:09:53 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id A8E616B0089 for ; Wed, 5 Jun 2024 10:09:53 -0400 (EDT) Received: from smtpin25.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 312CD1614EE for ; Wed, 5 Jun 2024 14:09:53 +0000 (UTC) X-FDA: 82197018666.25.E0259CF Received: from NAM10-DM6-obe.outbound.protection.outlook.com (mail-dm6nam10on2084.outbound.protection.outlook.com [40.107.93.84]) by imf09.hostedemail.com (Postfix) with ESMTP id 66FD514001C for ; Wed, 5 Jun 2024 14:09:49 +0000 (UTC) Authentication-Results: imf09.hostedemail.com; dkim=pass header.d=Nvidia.com header.s=selector2 header.b=EaLsSoVb; dmarc=pass (policy=reject) header.from=nvidia.com; spf=pass (imf09.hostedemail.com: domain of ziy@nvidia.com designates 40.107.93.84 as permitted sender) smtp.mailfrom=ziy@nvidia.com; arc=pass ("microsoft.com:s=arcselector9901:i=1") ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1717596589; 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=X6Rdz3gLqP6jIJmp8YZDatHuTIMWf+FLNopTMnQ/Af8=; b=kFxv0ftnm6JQ34AHzSSVaMvOr+pAMM9cuMc/sfbHAKcrMOTALNMOYBxrebxRj74RgHebLb +wKMTrBdYSY2OGXZq/I2t1EfISO8zI2z1rRIWawat+Fauk0ZhqcblH+eDMNYBXAHXOAYbq y1bFYXEhQza4imji5q5GhzR32vJX39w= ARC-Authentication-Results: i=2; imf09.hostedemail.com; dkim=pass header.d=Nvidia.com header.s=selector2 header.b=EaLsSoVb; dmarc=pass (policy=reject) header.from=nvidia.com; spf=pass (imf09.hostedemail.com: domain of ziy@nvidia.com designates 40.107.93.84 as permitted sender) smtp.mailfrom=ziy@nvidia.com; arc=pass ("microsoft.com:s=arcselector9901:i=1") ARC-Seal: i=2; s=arc-20220608; d=hostedemail.com; t=1717596589; a=rsa-sha256; cv=pass; b=U25ocDTbD/QqF3OXvxNTLs6PSFwDIF0e3CeaufTAdWLx+kEfD+k1Pom/ZZgcQ7HJ9ZlTSk kqgWmOfLw8iT+C6TqnB1QO2cqPQC30VvDmL57jlToNKU7uKe+swz5QxzvmPEmcSuJ5t6n3 OeWvvbWRjlzztZ5kRyZvri55vfnlzp8= ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=IehODwUg2pPCGLuQxbfjqmiguLJBY6oCWBAqesO1k0iBe2nCedYNPCrWsOYf0RttvPxIuQBmdUxByF6DLDEa6u+AvjweUrAWWXBdx3u9e0hhxe/46L7twTqRjCIHa8IP3U+ImLfNu/kMuS8eJIrvnc08mX2Y+YrsosBQWr6WWHVOT2Ah6hM95GesFLeGTYAz0W7j61cIVD5FZzp8/R71wKprZNLllEbBfMLv6F9d+cNqrJORaI1dNkO9tdpryrzWjVd7D1z+2OAvmkszdFvtcWm4GQznhsEBLH2pC4d185cxvNqr8ZhOvC52SDQhtJ5MK7IxbSo3G/jRVsl9UlbqjA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; 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=X6Rdz3gLqP6jIJmp8YZDatHuTIMWf+FLNopTMnQ/Af8=; b=d40EHIjcy6TyOzihfsAaMXQB+31g2FnAIPCxWw55E6CFCdstTvn5wwQt6RSH71yWSScCKaFhol0+tH1NckUC+j7X4lcwkEMnjKKuJikjU+q3JdoYDDW9Va2HFu+xbe69IW2uBM1YjCePcymXWciGU3Yfd5KgSPtZ1gHs4quEoI95R6u7093GyoYFXHTiFyDt3fJ/REDZIr02sjIDn3CFbY/Uz6Sr95/JCFq/VlTdLx4SJiKdZb1UAUFPCc5cGa56rxJWl0cF3Hzv+cBcx8cExHSvp1YdQHM6BzvUWgIL/yKAYbNUgsdDUoj9Xqd+dYk9kD4z9xiAYzco3Wn8EE0+BA== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=nvidia.com; dmarc=pass action=none header.from=nvidia.com; dkim=pass header.d=nvidia.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=Nvidia.com; s=selector2; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=X6Rdz3gLqP6jIJmp8YZDatHuTIMWf+FLNopTMnQ/Af8=; b=EaLsSoVbmGkzmDtPGhMRtEVQ1+/Fi/PeofM+3Hx4COwsCh3QgE3kYSt7hmR/Hc+qWIm5Jr46GLbEO0bqMIS7OCNae+PTbFV9xLXse0DDvRWSN83OtVvBNu+Lk70BBHk/6Bjkt0GxONRHkmw4mktzxa0yy9Nm73I/FJxau8Sd5t8fJbTBm9582zg0BSkqgbD1/VZvM2kLRivW/ksNipTCnzNkzQj2y6eAS/2vvilQi/fenLlUkAB2O+GexFdK7rIGcTTsZM3PFFjybRXwqXbq4AcnhRQSojDOsMd4Y0BE9DSXu5FMLOZKgjs+vrqm9frXxHSaDIkDYktvE+7McY3MEg== Received: from DS7PR12MB5744.namprd12.prod.outlook.com (2603:10b6:8:73::18) by LV3PR12MB9117.namprd12.prod.outlook.com (2603:10b6:408:195::10) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.7633.25; Wed, 5 Jun 2024 14:09:25 +0000 Received: from DS7PR12MB5744.namprd12.prod.outlook.com ([fe80::f018:13a9:e165:6b7e]) by DS7PR12MB5744.namprd12.prod.outlook.com ([fe80::f018:13a9:e165:6b7e%4]) with mapi id 15.20.7633.021; Wed, 5 Jun 2024 14:09:25 +0000 From: Zi Yan To: ran xiaokai Cc: 21cnbao@gmail.com, akpm@linux-foundation.org, david@redhat.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, mhocko@kernel.org, v-songbaohua@oppo.com, xu.xin16@zte.com.cn, yang.yang29@zte.com.cn Subject: Re: [PATCH linux-next] mm: huge_memory: fix misused mapping_large_folio_support() for anon folios Date: Wed, 05 Jun 2024 07:08:31 -0700 X-Mailer: MailMate (1.14r6030) Message-ID: In-Reply-To: <20240605095406.891512-1-ranxiaokai627@163.com> References: <20240605095406.891512-1-ranxiaokai627@163.com> Content-Type: multipart/signed; boundary="=_MailMate_781623F8-93FE-4E65-9300-2E2C849131AA_="; micalg=pgp-sha512; protocol="application/pgp-signature" X-ClientProxiedBy: CH0PR03CA0094.namprd03.prod.outlook.com (2603:10b6:610:cd::9) To DS7PR12MB5744.namprd12.prod.outlook.com (2603:10b6:8:73::18) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: DS7PR12MB5744:EE_|LV3PR12MB9117:EE_ X-MS-Office365-Filtering-Correlation-Id: 05a60b7f-5ec3-44a9-f0b5-08dc85691ace X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230031|7416005|376005|366007|1800799015; X-Microsoft-Antispam-Message-Info: =?us-ascii?Q?WbF058qb+iKIkHgja+Ze7KHllAM+pBMOcC5VqRPigwzfG+0zhOKvAmmbM2S2?= =?us-ascii?Q?ZtJ0Xqkf8t4/zcxh99SQQKiJ4eRT1F9DPvOUmEDsnlC3Lyt8OiI/z8wE0MdK?= =?us-ascii?Q?CPW4dQl5Jhgi21PU4C1zwOav15wmPie8+zwjs8SzjC3GQVqJ/cvtGUQSa2VJ?= =?us-ascii?Q?Juq3m8fAOGzZDIbcwcApLkkGyKqI06wsgSiFluCt1o0hSiYYmwaZDsTaOd7c?= =?us-ascii?Q?CSzYUpKkubzWgise2R9ei9zar32ZePpsf97EZ2SP66Yb8onJRF6vaKndxH/3?= =?us-ascii?Q?LyKKSMbpEXPaVwbLWp/Mr3IutthyEAIsO0bjonn3HNk0q3xJ8IQUrwgYa4G1?= =?us-ascii?Q?sJeZv6z/BWLVDJ4O10TU+mYFJvbBAZJbOyy5BUkGPwV5OiJywaZI097mK3IA?= =?us-ascii?Q?mBm5nAueE0C17z7x4rb0Uu2eKZ4bu9dyt9H+RbLtMsegtxWHbiplTlM/BW15?= =?us-ascii?Q?0TcT0aY9LcqsTa1b6ehkg1DXbnDbTFA+fKPys4KK67BEKMQRf5iQrTfrqiiH?= =?us-ascii?Q?Dw/TS4T2subl1G0FrHD5W8ly/Ceznr4TxOek00TME5yO/NtTTLj227dLX9bL?= =?us-ascii?Q?gWI+nRTP7BS2hxTv6loT/Zk9OiLabD/GRqk6Y2qLcDs2QNnBngykXlwlwdt7?= =?us-ascii?Q?2up8TyU1d81cLuiKuJfVOBZ2Bq0omKSZ4L+ygi4ibn4BTppaHg9zqN2kqiF3?= =?us-ascii?Q?EfW8xw9F6Q3uBs/Lg7OFRddHSX+HJumWW8I1MFZmQOnsB3nuqqF6by7EkDUW?= =?us-ascii?Q?5TD3r2PkBJGL6AKESdvVCl/TYBt7tAwbc7VSLYMhHJMPPWvvWrnbo2m3ClPd?= =?us-ascii?Q?zB8YePol9cCIzIlDNFW39obQ7VlDJw2c7cTmn7rjiLRMUmNGUEGiEfSoxHt3?= =?us-ascii?Q?HdRrcoSX6/jDI6H1XG4kFZ7psfHCGeMN8ZL/2GnBxNhp/yS72Pte73IEyIkD?= =?us-ascii?Q?RAmXuBDO5CEpjaDvIcOoNv4zFVd4KpbtjMyN5wq9ezSnlqYLFFQaFdh34qCJ?= =?us-ascii?Q?kEQBiMWYfNgZPuSPNmcVajS50UOGpx0cEe2iCMGYy5Sh9kFw3U34fcimNWpJ?= =?us-ascii?Q?8bIcJVuUQRrJgjpuEmmwhswS0qa6HWR4fNMClqLecM/47ewFCCp6atwW7OJF?= =?us-ascii?Q?gc0gPo+pVZ7h/Hjd8Qexy1m7YppkVjvs6kyopyGyn6vD6gpL01W5aBXgYyNi?= =?us-ascii?Q?Obj54KeZMnj02O+S/EMhY4ZjalHEdxvHa21Z1cDidoficgw+4QZ+dncgeI6b?= =?us-ascii?Q?0uJWVSZdkpYKzdyUu96XLLlsm0SHBPVhDoDwZ3q8TBc9Xe56gDXYqmwCj+DU?= =?us-ascii?Q?7dxpaykYCS7U+e/HdAN5CHat?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:DS7PR12MB5744.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230031)(7416005)(376005)(366007)(1800799015);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?U+0TnoCzjwbrUzqkp8snfg5e1uqmWYYAOaG7lr/XUPbxx9Sw2HqS3EpNGu9T?= =?us-ascii?Q?vszMfaVLCvKlyfj41Z5H1zMP21uz1CHmmIyriWCo9NK/XXG+CXS8RHP9+ke+?= =?us-ascii?Q?qrCVdLeNj4qHGoXQ8pj2TqG3RkcBLfUfO3suHfktdA+pRkfpu+YLzGbr1R2L?= =?us-ascii?Q?x58BSiIoXVdx74ap6wEFbBd7r+Q1b09+oOhNMfxDJzUaBSvyCO1GKf/kLv6/?= =?us-ascii?Q?3l6K7j5cBWcMQMGBjrqGmh4CoV2ZY68nca+pCasXGeceteOaQ5yelIUh1eoS?= =?us-ascii?Q?Ck0uykAgWQJa+X92fHPvAnek/K+bRIKPbCXI5j4uIqXhPnvSaGlOGQIrXvKM?= =?us-ascii?Q?ko3zwTsqC6xsILGNKnY3qvDXTr7iBnWmELrS6rOOgGk+9ulVx24vAxzmNiBR?= =?us-ascii?Q?MeTIysh+yEAUVYnSyoQhLKIr1hzsJ4XNBJfqzR7hnh3cYXeIIAE2OK5Q5b8U?= =?us-ascii?Q?xDSq2RKspf/tsNH+sDHFNDZysJdnNQ3CGQmO/K2gM9HN8ddwkcLPk7SFOsZn?= =?us-ascii?Q?klkt+i8C4GmnoCVUsPxSBuUH6/4HvOxGF5+BhrqcmU1DpRXn521IZkQ0cbUo?= =?us-ascii?Q?c7JDkHOgfKuDu+Ry8GGo5Yv2T7xDXv88HNtVAm2Wt2KEIYwPSCyMuLSSfQco?= =?us-ascii?Q?nbwNCaxKj+fPpQEZe9SWU1nWryygeHpnz+n+wt+9q2FcX5BuIwIlvT7Ol9F6?= =?us-ascii?Q?AAATgicw2AZREgY9hj/9XGrMw+gq+HJny0koggwCuUQRyjkCrU9771CP53jI?= =?us-ascii?Q?Jj9QTxOhH4/986bfFdZg/YxQ7SWOSJbeJs74UcrB33aaUFK3iUVTUAqphYam?= =?us-ascii?Q?Gjo8nwoV526aPmY99mPWrRxHE6SbANG3oI5E1LGrgtKMTEWDxJM4p2KVbNFL?= =?us-ascii?Q?VH+QUxM5xWL9xFYEtecl/RHqNqPqimLxgWWbujicuf8xmG75cdxDxxYAe6g8?= =?us-ascii?Q?nfPWglsdvHGkh5Ey4Txyd43uIcj7nCFbOiSJZHLAwrwwsnLnp3Un5H8gqjEN?= =?us-ascii?Q?7SEdNVWmUyP8psKrq6etDH9IuVe3RFcIKb9nxsGTDVyRArz9tDofheOMQrGp?= =?us-ascii?Q?2Y9Ac1wiFvaKfY0lPTiA2DbEyxOO3pyJeau8cOax/CYlu3R8rdaOkZ6Buidl?= =?us-ascii?Q?QQFvS8ZIgad/ZloUMjRjc1XZrvLoaHVp5noyAlflWKq213V4jQUcv8yd15Z4?= =?us-ascii?Q?he2iMhwGzpNwvlJ1y9TrYhnxjMAUMTFpPVs2Ix0hhBcvHW/JRqJ3mth8tvGN?= =?us-ascii?Q?3MqEJVd4azPDzlt3fSzBwga0cGrpDZOS6Om7LLfN7QM1hFJkIBklv8z/E0J+?= =?us-ascii?Q?2Vp+Ih8myic+qWsdref34p4IHFPtO+J44cmQoMZdwN7aKLfRu3vE+NqoHO8a?= =?us-ascii?Q?SwG19lXoFYyg3gjZqVVhLrEv6th3IOSSUVphIHMywBY3xWIa8OGIA9am/yXM?= =?us-ascii?Q?ct0LvjvbKsA80SptdJb8nzU5MC+OAmEJNnN4AyksgXgeSL4Z0dM4uUs012mi?= =?us-ascii?Q?nSSYxNbd/A0y7Yuse0tR9UXKy4KbM/3NsrVP+nQYmH1GSff/ldgcwbGuNpeQ?= =?us-ascii?Q?7gvZCp1GubD8trpVhYg=3D?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 05a60b7f-5ec3-44a9-f0b5-08dc85691ace X-MS-Exchange-CrossTenant-AuthSource: DS7PR12MB5744.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 05 Jun 2024 14:09:24.9777 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: A0monpOIhOxp4yK6pQzgZs507VoLkNhc7dP7I61kHBCic+Y6A7N4iaxDljd/vCp1 X-MS-Exchange-Transport-CrossTenantHeadersStamped: LV3PR12MB9117 X-Rspamd-Queue-Id: 66FD514001C X-Stat-Signature: gubcuxpdzqahmaxy4cxf7udihfxxjcy6 X-Rspam-User: X-Rspamd-Server: rspam04 X-HE-Tag: 1717596589-196252 X-HE-Meta: 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 j3QlpOCB eU51BKzay0ObQodID3gWQeQrVcznbykWh+gdV8yKnadZbBOTBa0ugxOdqeQxcG74g9wRXgBKhMIkduxC+8syGhgG53cEb6GOlCXUcVewXezzGEbEzOLMAn9GdoDlmHYcgljBV2mOBUyWvPMDkKpwti1SkLa6+7kLAlhnHflXWATj+ZoE9nyQ4L7EyoRLsq+tKTGLYNUXZkT62+tf8QQ5YeEsKS3c15OP62g4W23mRsECx1/GZ4XevsMtTp5zG8KY0qRUakmDYXHGx10gAOLaR85QXxnhL3+9hmiESyPVvXkFLvotBgdgHo3mf1gs6HV6V1DHnrfANnRVHCXUy01DCKSwhOknHsvQu5p0MwWvPNXb/j1VoXu1MTR+Iaz93TEzeyvGz1yclll/rth2+Dns6fPADQU4iolk5tRzvyAG/vV0Cva1fvmi6vH3g/uoWdBX9ucCR 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: --=_MailMate_781623F8-93FE-4E65-9300-2E2C849131AA_= Content-Type: text/plain Content-Transfer-Encoding: quoted-printable On 5 Jun 2024, at 2:54, ran xiaokai wrote: >> On Tue, Jun 4, 2024 at 5:47?PM wrote: >>> >>> From: Ran Xiaokai >>> >>> When I did a large folios split test, a WARNING >>> "[ 5059.122759][ T166] Cannot split file folio to non-0 order" >>> was triggered. But my test cases are only for anonmous folios. >>> while mapping_large_folio_support() is only reasonable for page >>> cache folios. >>> >>> In split_huge_page_to_list_to_order(), the folio passed to >>> mapping_large_folio_support() maybe anonmous folio. The >>> folio_test_anon() check is missing. So the split of the anonmous THP >>> is failed. This is also the same for shmem_mapping(). We'd better add= >>> a check for both. But the shmem_mapping() in __split_huge_page() is >>> not involved, as for anonmous folios, the end parameter is set to -1,= so >>> (head[i].index >=3D end) is always false. shmem_mapping() is not call= ed. >>> >>> Using /sys/kernel/debug/split_huge_pages to verify this, with this >>> patch, large anon THP is successfully split and the warning is ceased= =2E >>> >>> Signed-off-by: Ran Xiaokai >>> Cc: xu xin >>> Cc: Yang Yang >>> --- >>> mm/huge_memory.c | 38 ++++++++++++++++++++------------------ >>> 1 file changed, 20 insertions(+), 18 deletions(-) >>> >>> diff --git a/mm/huge_memory.c b/mm/huge_memory.c >>> index 317de2afd371..4c9c7e5ea20c 100644 >>> --- a/mm/huge_memory.c >>> +++ b/mm/huge_memory.c >>> @@ -3009,31 +3009,33 @@ int split_huge_page_to_list_to_order(struct p= age *page, struct list_head *list, >>> if (new_order >=3D folio_order(folio)) >>> return -EINVAL; >>> >>> - /* Cannot split anonymous THP to order-1 */ >>> - if (new_order =3D=3D 1 && folio_test_anon(folio)) { >>> - VM_WARN_ONCE(1, "Cannot split to order-1 folio"); >>> - return -EINVAL; >>> - } >>> - >>> if (new_order) { >>> /* Only swapping a whole PMD-mapped folio is supporte= d */ >>> if (folio_test_swapcache(folio)) >>> return -EINVAL; >>> - /* Split shmem folio to non-zero order not supported = */ >>> - if (shmem_mapping(folio->mapping)) { >>> - VM_WARN_ONCE(1, >>> - "Cannot split shmem folio to non-0 or= der"); >>> - return -EINVAL; >>> - } >>> - /* No split if the file system does not support large= folio */ >>> - if (!mapping_large_folio_support(folio->mapping)) { >>> - VM_WARN_ONCE(1, >>> - "Cannot split file folio to non-0 ord= er"); >>> - return -EINVAL; >>> + >>> + if (folio_test_anon(folio)) { >>> + /* Cannot split anonymous THP to order-1 */ >>> + if (new_order =3D=3D 1) { >>> + VM_WARN_ONCE(1, "Cannot split to orde= r-1 folio"); >>> + return -EINVAL; >>> + } >>> + } else { >>> + /* Split shmem folio to non-zero order not su= pported */ >>> + if (shmem_mapping(folio->mapping)) { >>> + VM_WARN_ONCE(1, >>> + "Cannot split shmem folio to = non-0 order"); >>> + return -EINVAL; >>> + } >>> + /* No split if the file system does not suppo= rt large folio */ >>> + if (!mapping_large_folio_support(folio->mappi= ng)) { >>> + VM_WARN_ONCE(1, >>> + "Cannot split file folio to n= on-0 order"); >>> + return -EINVAL; >>> + } >> >> Am I missing something? if file system doesn't support large folio, >> how could the large folio start to exist from the first place while it= s >> mapping points to a file which doesn't support large folio? > > I think it is the CONFIG_READ_ONLY_THP_FOR_FS case. > khugepaged will try to collapse read-only file-backed pages to 2M THP. Can you add this information to the commit log in your next version? Best Regards, Yan, Zi --=_MailMate_781623F8-93FE-4E65-9300-2E2C849131AA_= Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename=signature.asc Content-Type: application/pgp-signature; name=signature.asc -----BEGIN PGP SIGNATURE----- iQJDBAEBCgAtFiEEh7yFAW3gwjwQ4C9anbJR82th+ooFAmZgcWAPHHppeUBudmlk aWEuY29tAAoJEJ2yUfNrYfqKhP0P/1CLIaYaV64XGPZzdAw+FS0dygPHkwxHDicv OLGxGPsGgq0KFqPUAtlNiSf8BRYFPfg2G+JHH6BEYj+EatH+szvlTJQSt/i1vmyG jotSQfY2jDTWKwlJ3X+u9UTiuMHDPHpCbo8lni8AjU3AYLOo4HXds9tvNkDwhXp3 Hiu/A8j57cXU3Nxk0vmp9Uqf5Wh9ZTDLolgrW3DMqfqj81JJX5+NOr55qOo68tob 9M7ZAIBwIjB1B5DmdNTuyletDPlyLsUQ7aNXtwITtsu+9jLNDtGKngZ+jGhxre62 rPBgQo+TJyGdhXHhReTNWmwdT31TJiw0emVQ/BMOZDE2GsQEO8+aCJfmXDzq4C6x wPSUTdqbgwM7h33QzGN0pTfPHqfVC2YTPMio0EbvjJ/FVRHbtETAyNgujamgrePr 3X7RWtax7I17mFponyfEsaIYCpDH/eveca3J4s1HXQ8M/qoyf+nJvy3tMzNJwRh+ sDIbjm2sPPiVYedi6JKPx1fxyiEErxQNItFNWgXSgziTGN8xlKA5S2ZE+1Zev/uF RkV1ROVZ0psB3KLXUCV2D704R31ayVZkywswIF3+MsNNmCQlT2bCuAXUjFYNJ5nD t3l4i/cOLVkVOixXWMKpubyf+WzKqIuApTxH5e9vxAcqc5Q9z23FLyM9T0u/nI2P cfhAX/Gy =iCUo -----END PGP SIGNATURE----- --=_MailMate_781623F8-93FE-4E65-9300-2E2C849131AA_=--