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 6706CD26D92 for ; Fri, 9 Jan 2026 18:39:01 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id B06FC6B0005; Fri, 9 Jan 2026 13:39:00 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id AB4C66B0089; Fri, 9 Jan 2026 13:39:00 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 941DE6B008A; Fri, 9 Jan 2026 13:39:00 -0500 (EST) 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 7B5CC6B0005 for ; Fri, 9 Jan 2026 13:39:00 -0500 (EST) Received: from smtpin27.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 203D6BACDF for ; Fri, 9 Jan 2026 18:39:00 +0000 (UTC) X-FDA: 84313287240.27.33BA4CB Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.13]) by imf01.hostedemail.com (Postfix) with ESMTP id 740564000C for ; Fri, 9 Jan 2026 18:38:56 +0000 (UTC) Authentication-Results: imf01.hostedemail.com; dkim=pass header.d=intel.com header.s=Intel header.b=Q9UYoH6E; spf=pass (imf01.hostedemail.com: domain of matthew.brost@intel.com designates 198.175.65.13 as permitted sender) smtp.mailfrom=matthew.brost@intel.com; dmarc=pass (policy=none) header.from=intel.com; arc=reject ("signature check failed: fail, {[1] = sig:microsoft.com:reject}") ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1767983936; 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=fBco+iQ1f64WE48BIvAzmZkXC5ARrO/1sD67hHZzu7c=; b=jWMoArQmJz6516daQT2CX92bNf763ieqL1ONY5yQ9nqKVqOMSI4/1vc9uB6LW+M2FPHNiT 6bsZu47XYpoMRhxFa6gGwEiQOthkMfDidVkgVHfJBgw4OtD/o7OHKJDUSQBBaAe6ysmXzL WlhE6CVIJiqrY2AuyTJew3jHF5LY3rQ= ARC-Authentication-Results: i=2; imf01.hostedemail.com; dkim=pass header.d=intel.com header.s=Intel header.b=Q9UYoH6E; spf=pass (imf01.hostedemail.com: domain of matthew.brost@intel.com designates 198.175.65.13 as permitted sender) smtp.mailfrom=matthew.brost@intel.com; dmarc=pass (policy=none) header.from=intel.com; arc=reject ("signature check failed: fail, {[1] = sig:microsoft.com:reject}") ARC-Seal: i=2; s=arc-20220608; d=hostedemail.com; t=1767983936; a=rsa-sha256; cv=fail; b=qO9G7U/MiPOxKH0LgRiROQdE8NJjEkC1s52eGuoyi9v+g7mBrqGVo7hrCfVt0iVY3jWO9Y C/eOn0Y1knIRhHLgT9PDoWwvLj1eWzkZ8QfrLJVgqZDeIULqmQPS4B68Ueps9z+1qMx+I0 zW5a+hyEKuBTyTWCu9NEEzboxMMoGGA= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1767983937; x=1799519937; h=date:from:to:cc:subject:message-id:references: in-reply-to:mime-version; bh=zPmX6c0J/cz8TQKoQNIIpvhwx4cCkDt72qssvUUUChk=; b=Q9UYoH6EOEA4TbjIjHwibrmnPcLYz85FCuZ1SRGOML9hSCdXPkVnh1RA CRnAJsjNZIvhQmzd0cdfmLP1Srr+17Cb4QW3c/XKErIzvZhmbsyBkI0mv 7mj5LPzZMtZW7SjeqO/b3q3EJW5UCNEWKw0Y7UTflrshlUY8nyT9GK9R0 hdTogTZIrOZ9O8EnVBbkXXyWMQj0l8ELPhNfQuzOQJWBgx2cmqxICVJvY nEpEklG8aK9F0ZDMDm+Fw/05yVqyDAR+GMsGthsR+/0GFGhNRiyaLyoXF 0ixHRPRiPgbXjaXGtKcJ5Zt/AK/R2hDOOQV12rR7AdbforXkI7bySXZqm A==; X-CSE-ConnectionGUID: S1fgqB2sSmuRbwDelcdZnQ== X-CSE-MsgGUID: LFrd4toTRsekbLksWPbyYA== X-IronPort-AV: E=McAfee;i="6800,10657,11666"; a="80475316" X-IronPort-AV: E=Sophos;i="6.21,214,1763452800"; d="scan'208";a="80475316" Received: from fmviesa010.fm.intel.com ([10.60.135.150]) by orvoesa105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Jan 2026 10:38:55 -0800 X-CSE-ConnectionGUID: CR+cU3l7QHGZNunw0xKyhQ== X-CSE-MsgGUID: JBFuC8caTYy8B91TI4tdPg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.21,214,1763452800"; d="scan'208";a="204324256" Received: from orsmsx902.amr.corp.intel.com ([10.22.229.24]) by fmviesa010.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Jan 2026 10:38:54 -0800 Received: from ORSMSX901.amr.corp.intel.com (10.22.229.23) by ORSMSX902.amr.corp.intel.com (10.22.229.24) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.29; Fri, 9 Jan 2026 10:38:53 -0800 Received: from ORSEDG901.ED.cps.intel.com (10.7.248.11) by ORSMSX901.amr.corp.intel.com (10.22.229.23) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.29 via Frontend Transport; Fri, 9 Jan 2026 10:38:53 -0800 Received: from PH0PR06CU001.outbound.protection.outlook.com (40.107.208.64) by edgegateway.intel.com (134.134.137.111) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.29; Fri, 9 Jan 2026 10:38:53 -0800 ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=Bs+zYY50t5beBokFTWPedBXLIM/gOg/eQiH1+4llvxARahJBR7uZGCE0Ze3+RiEclJ7GiJocbeWKpx/v+mSVtgKCB1M7vuQl0SkN9O1PWwL3L8L1urNQYvW5chWJAATMqt9HnFVSSo/b295agPF2XPvyfl1pgN1GYGqxZCjyu66Bhi9p/7kSHxuKVhyHl16M90C2z2ju1pha0M+s1BA6zOGHUhdcHv0tVuY8ik0N+nVAhPorCYLkz/Y0e9PyQFD/gRYb8vSNOVIccrCpikXDlDoatowN5AYOaEmVzctLpO688rujic/nI+HD6jmINVy/UpGSR0zwFGDpJSblfjh3wg== 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=fBco+iQ1f64WE48BIvAzmZkXC5ARrO/1sD67hHZzu7c=; b=MXowtL26Hj+wGcJ7EUE8Vgrq76+WHbFtKs05gkuS/vmLBcA/8ZjZMSa0VYumJRIUexmsQJWdB7qm33jmpFscnVwvxix3LlZ05w6jilN8ZHJfBvEoRZvJfOxN58T8lwMCrJeBoDdHnzyPNvsFRm4M7PK5BICQ6sUO9i0bQOymE4FdlnBZe9ATR9F/QdrCq0MBE2QPwjKaBCluit5Q5F7PQdI9FijzDGGkp+AFjmCjz439tOUlSPpu4FmcK7WY2hgcPZeLBclK10IKNMh5v4JKqPHloGb4VJa1okr9oJLyko17pf0M+NDMv8LVkwUkVDGiWMignTi1voG3lGgFerWvOg== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=intel.com; dmarc=pass action=none header.from=intel.com; dkim=pass header.d=intel.com; arc=none Received: from PH7PR11MB6522.namprd11.prod.outlook.com (2603:10b6:510:212::12) by DS0PR11MB7559.namprd11.prod.outlook.com (2603:10b6:8:146::7) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9499.5; Fri, 9 Jan 2026 18:38:46 +0000 Received: from PH7PR11MB6522.namprd11.prod.outlook.com ([fe80::9e94:e21f:e11a:332]) by PH7PR11MB6522.namprd11.prod.outlook.com ([fe80::9e94:e21f:e11a:332%7]) with mapi id 15.20.9456.015; Fri, 9 Jan 2026 18:38:46 +0000 Date: Fri, 9 Jan 2026 10:38:43 -0800 From: Matthew Brost To: "David Hildenbrand (Red Hat)" CC: Zi Yan , Francois Dugast , , , "Balbir Singh" , Andrew Morton , Lorenzo Stoakes , Baolin Wang , "Liam R. Howlett" , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , , , Alistair Popple Subject: Re: [PATCH v3 1/7] mm: Add folio_split_unref helper Message-ID: References: <20260109085605.443316-1-francois.dugast@intel.com> <20260109085605.443316-2-francois.dugast@intel.com> <59fb1669-2908-4cab-b3c0-b97479da3fb9@kernel.org> <1319a24a-bcfc-47e5-a022-f5d00994acc9@kernel.org> <85033126-c60a-4cac-8f6f-5bd2f6102fec@kernel.org> Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <85033126-c60a-4cac-8f6f-5bd2f6102fec@kernel.org> X-ClientProxiedBy: SJ0PR03CA0370.namprd03.prod.outlook.com (2603:10b6:a03:3a1::15) To PH7PR11MB6522.namprd11.prod.outlook.com (2603:10b6:510:212::12) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: PH7PR11MB6522:EE_|DS0PR11MB7559:EE_ X-MS-Office365-Filtering-Correlation-Id: 805fe162-bf6b-4cd9-eefd-08de4fae5285 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|366016|1800799024|7416014|376014; X-Microsoft-Antispam-Message-Info: =?us-ascii?Q?8bZcg2u2KNxyOnD7oANEXd64k0l+S88e8fWyK9SS4Y7PYTFmywmitrYEtzJ5?= =?us-ascii?Q?mHVXYGuIcFBF+QIQdVVpuqIbkXvuvHQCODTz+9J+EABqm31U4mBoaAIxT6kX?= =?us-ascii?Q?I0MnFuaYi4aJg9RedUOnXj83kmnn69dfTn2WgmP6YtRB3f1vPT52WeJVVbGi?= =?us-ascii?Q?XQi1fmsl16s+9ogVWChLK+WKgcFpN06C5ZsdwUpV1IMThqvxK5vKnG0238fe?= =?us-ascii?Q?Cn1G1L6f4QC8axpWN4R/MjQJwwBd3/ryqcOqU6mxZ+uKDG5DeLVsIU7QU+we?= =?us-ascii?Q?anav3CvAfgGYGH+525OYNT0HRC22P1kwvkY3WHakkZfHDOlVH231J6k71cJS?= =?us-ascii?Q?ro/i/8Gyb49vTjBn4skcVnM1hgHq65fyiXU9C7zNDUlFabkG8f8j5OhlamOt?= =?us-ascii?Q?oDSRBgn8B8cU9j8/0JFKdcNOOC3hRcWslubATGw0USOYloRub+VTZ7WSQAMp?= =?us-ascii?Q?WknxVyYDjgvbtHyuZA5TEa7vTL+IE4VpltZED2XmxvCmuSY29A7Akaqt/X2r?= =?us-ascii?Q?JE9DOfunDwvbOZJscdSEdL3TP5JhR5AVHKevylhclslQ/OpPSD9zuLkEFYgr?= =?us-ascii?Q?1aKeh/T7j1u42cBZgWe0F/34VKH217hc7wTPStkSSd5sDWXmAEjYiVeYXjfG?= =?us-ascii?Q?ekICkFb6PUge6SQQ61W6sy9cICLXQE+agoXJ58GnXlG9GNKQ8gpg0jVhVM3z?= =?us-ascii?Q?JDQez9v06Fi/2SbEW44lSJV4FHL4EKHPv5tvy4fs6goI2y4CiWvl6MqDNqUM?= =?us-ascii?Q?XO4Ej27fRm9kg0cMCRVMw7K2btx64LMn6AeZMYBXGpN8rDzMVOffuC0DAo6Q?= =?us-ascii?Q?Dm/2C0Iiyp/cmOxrnSO/nzdRsjrTPpNqnWqkYII6oSomu+6V6T6kh6Gnv8wn?= =?us-ascii?Q?ilYyAwtnl25bCmxkUVczIoCQWqVIQ3nhIAODbHGdvtE2G5hrI1FHgA/G9EgS?= =?us-ascii?Q?xn+G0TN8T+JEg3GGlZIM6xtw5toqXlnBk8TYa4bXYgN14M5AGZ5uOL3SHnSk?= =?us-ascii?Q?gIfjTgLbTYHcn1jDSMFDtRBumU/fmsxTgtJNog/dN2v5Twt0Bnn/jR7zBxzu?= =?us-ascii?Q?m8jMr5lT2KOZQg+tPnYSlgzboVIln7ZAEItz7lu9Czp3jZ5KkF2g7OVWZ7wU?= =?us-ascii?Q?iQjv0hRn7HXsJgGRLHjO7En/kcXqqGe0gxBblyLlVh8pBLkplYfE2Z71/g7n?= =?us-ascii?Q?uLmav9oLqZZnY1ed22Bwxo2OLc7LA8Bnd8nLbhFxej1yzq8RBCn5t9ulasoc?= =?us-ascii?Q?F5NlZklHd4x803ZzY//ZRpDxLaFxXDuwvl1nV2kxveXRVw28rNrjgd2XKM5o?= =?us-ascii?Q?Ox/AcOH+70rjwJMkVaWCSl1N5xdI52KI3WiKG5xN221AMsRGK7x3jXd+BIMh?= =?us-ascii?Q?UxEDc10v7RQSMjBAGTidYNvJJt2CVU1NEoCffU5TUwGFTObxJQ=3D=3D?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:PH7PR11MB6522.namprd11.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(366016)(1800799024)(7416014)(376014);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?vSagL6H9CTMUmmcBi4Nn33uqmS5mPOBMnDnjV5s9YRdRDqQZrIM0boztcTyD?= =?us-ascii?Q?TQ57tNb8/dXDsKMLg/lXTtxz+f6qyfXkId5Bvnr+yJ8bGckagXRmVkv7Y6tP?= =?us-ascii?Q?yPorg9WxRiPyUMceazwxmNRDzXbwrqiFo0Cjb3sjrbqPLAAl1LIB6d+Ehbui?= =?us-ascii?Q?GopL12DOl4RkVu/0KyJODqfPMM52qAGs8pofsIfwdmDVsXyXFQVj1HHR/g30?= =?us-ascii?Q?FDk294sb9voc182BlioMkV0nJsFxELec2nmppxwC7VYeNcghUAVk+csOKOsY?= =?us-ascii?Q?9en4GXrJWnwUPqDFvQMhdX3GDZPx2nrOa3xS9lRlAs0PG3OZxtZ+TOCnsU+A?= =?us-ascii?Q?7GRdbdZ+ybuxiQP/dBDbMWVnZwigh58weGo2h2T++6ZYEPf4AqrOxNZ13N5f?= =?us-ascii?Q?xZ+UWbeRvCktzaIMUkR4HINdZK/7u64sfgX2r7t2pb+qE2jl7kemqlsOwtCs?= =?us-ascii?Q?/F1Tp4wHFlLN6ch7CtcILAmxzddL7E1Lv4oK9KnrrW56khNhy/cC+tZb9ROP?= =?us-ascii?Q?BJ1/dpRr4uY68kGnHZChKdtpvLPNrKdPwvvd7RR4BjGAVjwuV+c7APHmbvt5?= =?us-ascii?Q?G65WhvhD+d+KGq/G/rUb4dLPlOEOYC93dgnORUcu/DxdDHdf63i4cDl1g7nv?= =?us-ascii?Q?21Z/GkN2PuklQxSxBQ/FeFIYVmEpJf+MZlvro8z5pp1Z/XAxNp60LdC8CdbE?= =?us-ascii?Q?x6qU9DqRfpNeLT569hg1NpKBom4fYcgDIxtfySkGdpsdY6aSe/N4il52j1tp?= =?us-ascii?Q?pcTVCKKdq5WEXJnAwWX2w31XaCCb+sOOqq2AQz+2UsPCnAXF60tCLettnUwh?= =?us-ascii?Q?/p1SVFreHlhh7BaFJs8ynLp0lEwsO0qzNykCOTk0eAUaLPJn4bw8KjBw3HR7?= =?us-ascii?Q?+VAcrzjnNRpgMaEeX5jbXko/KQu2HwkKFsfJVoZfB2rhM8+2eRvHJ96k1r9s?= =?us-ascii?Q?hN93POZxF8kJwJVuuGFv3r2ao4rT+/GPffnlNsjrd5c+n3nS6KAgS9E+ZFi4?= =?us-ascii?Q?+K+BYVBiGu6U5MLbB1prYrEoB/5rBa7WX9hkYnD5VCLmcjIO4w1uKjykDKYI?= =?us-ascii?Q?aLpo+p1YlsJ+eGnoLTQBeIBrarBukKdF9zM5B/oTWb5IT0IwZULyEfyfmduT?= =?us-ascii?Q?vK56oH7GY8bqppBO/viMsSeXipoUmAGixAVrmAuQgFsboDRnd0kMtMOeYE9E?= =?us-ascii?Q?NlLNQ7oitUJ75G8sLHggy3W910G4TGyZXwN/pk9FhBFq0zMv054LlyvPcVc/?= =?us-ascii?Q?11hBl9QLtm8QV8hy212UvcCYbyAOjJ5JW/vzupAUOmFKMsmhdOtOMUlzh7iy?= =?us-ascii?Q?Tli4ID8m9MKd8wpEktaFJ7tuuzyYYBU8sBuV8A3FmFNYMBlfWzeL+Vlu9VPu?= =?us-ascii?Q?9FJqwo82IU+pH7Dn9sQfhv+tdIQo/cb+kP6wp+aTdthFz0UDoAXx5rPWZyXW?= =?us-ascii?Q?QREmPLrkIAgOJejkmf/2YFLaRv5wmKsjVdjqBwxamKWenuBEV+F08DTec3a1?= =?us-ascii?Q?Ds5XjluYqPPaiYZLBtZik8KW1A00b4E5obk3fUXn52fs4FuZ24mmS3TJ7hxM?= =?us-ascii?Q?T/H8Y9watvP4zG6lx3NIlyXtVVCoBYL2ggcaDxJ79KDYtRpChiMQj9XbzdXW?= =?us-ascii?Q?cu9U4H4jXmF8emuQnv+BkRcg/1m7mkX5N0okruKqAYvZzhYHnzPW/fhR0hf4?= =?us-ascii?Q?x6EyDIiGP9CUkajmqHS+XYWEjsR+NDnHL30v2TAGRc7JDCYdIT0g8xdwfHL+?= =?us-ascii?Q?NpsLz6Xmz60eNMdVCoWJIBX3ZfdkfZU=3D?= X-MS-Exchange-CrossTenant-Network-Message-Id: 805fe162-bf6b-4cd9-eefd-08de4fae5285 X-MS-Exchange-CrossTenant-AuthSource: PH7PR11MB6522.namprd11.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 09 Jan 2026 18:38:46.1786 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 46c98d88-e344-4ed4-8496-4ed7712e255d X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: 0vOqZC++lDLqlm1KH5e2vVz3Vav7bFMVfwg+Tmox/o517Q4TalM8ex4isNIU7Et0EBQKdMIPmYYAqLnj4/awIw== X-MS-Exchange-Transport-CrossTenantHeadersStamped: DS0PR11MB7559 X-OriginatorOrg: intel.com X-Stat-Signature: g5nzfgt19c184eru3hs9prrqzst7abnd X-Rspam-User: X-Rspamd-Queue-Id: 740564000C X-Rspamd-Server: rspam08 X-HE-Tag: 1767983936-435463 X-HE-Meta: U2FsdGVkX1+rPKv5oYI585/DLRxCQEdOSn8Cy3ZqqT2LSKzhWZrAOkYSQFkLFq9xr4TYFEz1DNpST7yLe3cgtxQubgn9CZlJPLY1P80V8Yohznmf7nrk2LEAspzVZb1ayAca1s03dx+ZROIScnf2lncbzzGZFOTfBin8ARZTw81L0GJV1iLXP3uc3zYpekomgaoXas1niF9xwib73P1+O7cFupGgTHgNMcTDshxke8UJLaDCtq8sWQm7q/VV5de1KTTT3oLhygKG/QEbv9vLGha+366OlN6pTYdBB0Z35c8blKEHhbkHwhhw2ue7QM6LGAc0CsSmZkOMUou7S9mut/xiCDSHD2nEi/p1JQT9rGh0k+95tc55nxC60xOE3m4Jb21MxZ7iXQv6CHRIKhjYU8M1TMqNg960tffHlJSgzAWfxrx6l74+2Bt5jJMWv+JjMESjki5OQFIvVitEXrj4VryNoZA0QJ+PC1vrensJzWMJ+jVT/Cq3x5GK66EByOeasYFxw6X4UUMHSVP2fyFDHzpQSWRV4h9PqaApctOVNeR/a5vmgAc+vEflePpqCeOumO5TGocXm2ATwoyIQF+EesP0WxecAGLfKv+lk4GOE7Qd+0ntAyB4HYQ4OW0wuIicJJ6FIoAHakE4tPYhL0GIqhTTqOQ5fqKL3SbYDStISkbtd7zJJFgvxZm1DgPgsq2eYejMrX3U8ScYZslCa3NCKL4t0HoQq3kwtdenjze7tcHTNenYIBCa1HG2JBL+4kJFigPg/KOkj1wsfYVVRSSieUEnPOoAo0ARtn9+HgQXcfrIndTC9PfkXan10LXXUsgY1QIZPkwYthS07eQxw9gDkRK19MNFrFKVzOZEFxdKR5dUx6Azaz8fikAapfZ17zZ/Xn8ky0B0BCkvsrl80MsFNF3Sua+88nXBICRWfOAI1Viui71HBdcFveIH21d8a7Q882EFQzf4aRyGo2vwJgg 5drtol6m 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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 Fri, Jan 09, 2026 at 04:11:23PM +0100, David Hildenbrand (Red Hat) wrote: > On 1/9/26 15:30, Zi Yan wrote: > > On 9 Jan 2026, at 8:26, David Hildenbrand (Red Hat) wrote: > > > > > On 1/9/26 14:19, David Hildenbrand (Red Hat) wrote: > > > > On 1/9/26 09:54, Francois Dugast wrote: > > > > > From: Matthew Brost > > > > > > > > > > Add folio_split_unref helper which splits an unreferenced folio > > > > > > > > split_unref reads like "split and unref". > > > > > > > > You probably want to call this something like "folio_split_frozen" ? > > > > > > > > The very definition of "frozen" is "refcount = 0 ", so you can simplify > > > > the documentation. > > > > > > > > Are the folios you want to pass in there completely unused (-> free) or > > > > might they still be in use (e.g., migration entries point at them during > > > > folio split) > > > > > > > > So I am not sure yet if this should be "folio_split_frozen()" or > > > > "folio_split_freed()" or sth like that. > > > > > > > > I'm not CCed on the other patches in the series or the cover letter, so > > > > I don't see the context. Here is a patchwork link to the entire series: https://patchwork.freedesktop.org/series/159119/ > > > > > > > > > > Ah, I was CCed on #3 where we call this function on folios that are getting freed. > > > > > > In that case it would be acceptable to initialize folio->mapping (and folio->index?) of the split folios. Do we also have to initialize folio->flags, folio->private etc? > > > I lifted this code from FSDAX here: https://elixir.bootlin.com/linux/v6.18.4/source/fs/dax.c#L394 It seemly does everything we need for a zone_device split. > > > See __split_huge_page_tail(). > > > I'm not seeing this function defined anywhere. > > > folio_split_freed() would likely be best, because then it is clearer that there is absolutely no state to copy from the large folio. > > > > Yes, basically, we do not have a reverse function of prep_compound_page() and > > open codes the reverse process in free_pages_prepare(). For zone devices, > > zone_device_page_init() calls prep_compound_page() to form a folio but > > free_zone_device_folio() never does the reverse. FS DAX has its own > > dax_folio_put() to do it. Alistair suggested to come up with a helper > > function for both FS DAX and free_zone_device_folio(). > > > > Maybe free_zone_device_folio_prepare() is better. And put it in mm/memremap.c. +1 can rename and move. > > That would be even better, if we can limit this completely to zone_device. Yes, I believe this function should only used by device private, device coherent, and fsdax folios which are all zone_device. I can add warning in this function too if it is called on non-zone_device folio too. Matt > -- > Cheers > > David