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 6E5D1E77188 for ; Wed, 8 Jan 2025 22:23:32 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 9FCB46B007B; Wed, 8 Jan 2025 17:23:31 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 9AC1A6B0083; Wed, 8 Jan 2025 17:23:31 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7FEAA6B0085; Wed, 8 Jan 2025 17:23:31 -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 5DFFD6B007B for ; Wed, 8 Jan 2025 17:23:31 -0500 (EST) Received: from smtpin13.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id BF553141212 for ; Wed, 8 Jan 2025 22:23:30 +0000 (UTC) X-FDA: 82985712180.13.AF5F9CC Received: from mx0a-00069f02.pphosted.com (mx0a-00069f02.pphosted.com [205.220.165.32]) by imf19.hostedemail.com (Postfix) with ESMTP id 8DAC91A000F for ; Wed, 8 Jan 2025 22:23:27 +0000 (UTC) Authentication-Results: imf19.hostedemail.com; dkim=pass header.d=oracle.com header.s=corp-2023-11-20 header.b=OamOekWy; dkim=pass header.d=oracle.onmicrosoft.com header.s=selector2-oracle-onmicrosoft-com header.b=qFecOeoj; arc=pass ("microsoft.com:s=arcselector10001:i=1"); spf=pass (imf19.hostedemail.com: domain of lorenzo.stoakes@oracle.com designates 205.220.165.32 as permitted sender) smtp.mailfrom=lorenzo.stoakes@oracle.com; dmarc=pass (policy=reject) header.from=oracle.com ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1736375007; 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: references:dkim-signature; bh=nv6QcQAygthJPHmT788Jl9H9UoFhRufwGhS4FtIcR7k=; b=qRaLl/hfzr4rH3SzPr/+eRfJ6kuJdui0h17+h5dM+apgN3TM8hH5iTrNqJ78pbQjctOOaY FnJ1y2jSKtlKmGptaMiC5P63Hu1gdugHz1/1xPRxOGdt6m5V8Oc5sQnyOvolVEMNf7ebGZ lsYfsj9rkt08pbkKPwTxCz2wO9xAYsE= ARC-Seal: i=2; s=arc-20220608; d=hostedemail.com; t=1736375007; a=rsa-sha256; cv=pass; b=mxlT4AX1IiWsO/ZFNB/N2bCt8Fq/A97AvRzSG933Lq/ZsB7MX/xTtAunGZ5bi9/cGs9C9O GhpUn24qCAdmZ/hnr1ycI0Se1Z5VwNgqDKgoIZNkNswaRZR2rVr8UtOdAnjGrF1PW/H+Ri 3dNGnAb57LhFB9YsU1zSaRyzlK+d+ZE= ARC-Authentication-Results: i=2; imf19.hostedemail.com; dkim=pass header.d=oracle.com header.s=corp-2023-11-20 header.b=OamOekWy; dkim=pass header.d=oracle.onmicrosoft.com header.s=selector2-oracle-onmicrosoft-com header.b=qFecOeoj; arc=pass ("microsoft.com:s=arcselector10001:i=1"); spf=pass (imf19.hostedemail.com: domain of lorenzo.stoakes@oracle.com designates 205.220.165.32 as permitted sender) smtp.mailfrom=lorenzo.stoakes@oracle.com; dmarc=pass (policy=reject) header.from=oracle.com Received: from pps.filterd (m0246627.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 508M9Wtw004398; Wed, 8 Jan 2025 22:23:26 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=cc :content-type:date:from:message-id:mime-version:subject:to; s= corp-2023-11-20; bh=nv6QcQAygthJPHmT788Jl9H9UoFhRufwGhS4FtIcR7k=; b= OamOekWyA6uFNY8BXi4XNBpkvfJS1NKQE7cekYJY4k3hmgot+Of4b2xB9ZZEuKpI q8rLv9CdzXyj77LaVyILdGyoLKWgv0DmLDfhzMHldXns3EwpDOF4B7N7R5ckXEJB nX64uP9MLk5+b9xYrpeQth/xOudf0tLSQDmO+2cshog2vszF5/Rd8wmyn32MPs6d s6Ee/rlyuSi9GIMBlA7Z47y5r3HaWX+slEzFZPpkoFS70Ct8rC5apU+LLqzGFg// HWpX9vxI39+OJtLMBTCHl39md8h1U7cjYbExfr/N3rCXbPGXDc4dSv0RF65MMqZX 1ETzbcMkAsYnAt1BMzHHqg== Received: from iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com (iadpaimrmta03.appoci.oracle.com [130.35.103.27]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 43xuk084th-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 08 Jan 2025 22:23:25 +0000 (GMT) Received: from pps.filterd (iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com [127.0.0.1]) by iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com (8.18.1.2/8.18.1.2) with ESMTP id 508MF4wX010893; Wed, 8 Jan 2025 22:23:24 GMT Received: from nam12-bn8-obe.outbound.protection.outlook.com (mail-bn8nam12lp2175.outbound.protection.outlook.com [104.47.55.175]) by iadpaimrmta03.imrmtpd1.prodappiadaev1.oraclevcn.com (PPS) with ESMTPS id 43xuea62fe-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 08 Jan 2025 22:23:24 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=O9p9yceRJqUAseF1VjGcyZMuvwR1MkEQ+IevTFFiw9KftogV0UIz8AojKmJpkuXabWYkQWqe7dnaj/buzYqSud0Zh+6K6ePNltu+W8mLmhYKvgmkCqul5B6BU1xoe4w893fMFAcvj+3YmeaLOcyVJjhtLszG6+NyC1+kNCDQRvXNxLUdMSG4I0uo6/FTH4oFCsJsXmSDtje/mGjSfinDgTUlok0IEUakHkzGtC7uoAELS55+Fa+p6uDftpUwnbB/C7wYkJzUW+2viALH+whrX78uH0zDCqSu/zBh3ei/OvIIzW3wIDqccdlAwdUz4h65CthizxMlk/hoDKvNAGoJTw== 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=nv6QcQAygthJPHmT788Jl9H9UoFhRufwGhS4FtIcR7k=; b=DpP05YctUZ028cjgs2U0kzklkUYt6hKUFkmf2EcxDJOrZ3PBFZt6Oc00psHdTNyEvmA6c7u1psqywO7T81vB0RLmjfFUeNywyRp2bA7pCueV6lokJTAF0TX1M2ixnUyjICHww3ycrUoQmrC5/Pwf0bJR85gUBse9COR7dthYutzSqlnSDT9+d6Oyz73N76mpw5rzKl84OC/fSkaQZ/fL8W8jxHW+j/UZQHRSkpAIb2sr0MJ0ml2+Yrc1Ai3yHU9j4dLzusx34p7OSJsoWvCbLHxlNbuAd56Fi75dzAvNpD80v4HQx4NUYK5veSWipWw7i9Mva6Ch6hEpymOIKatDOQ== 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=nv6QcQAygthJPHmT788Jl9H9UoFhRufwGhS4FtIcR7k=; b=qFecOeojD3/yDvVNkg/7VoBOMf087H7KMUEn6lTNwaRm6vMeqWhBC0VRQByg48e5Wp+nqbhCwoflCyx2velPdnhwfcqQJdhy5aE6rG4eQZclot8beil7qHWQQyyUk5woaBiDGu67Qxvx5Fm3hXslc0ASt8o3iffBK/PBlxI5Do0= Received: from BYAPR10MB3366.namprd10.prod.outlook.com (2603:10b6:a03:14f::25) by IA1PR10MB5946.namprd10.prod.outlook.com (2603:10b6:208:3d6::9) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.8335.11; Wed, 8 Jan 2025 22:23:20 +0000 Received: from BYAPR10MB3366.namprd10.prod.outlook.com ([fe80::baf2:dff1:d471:1c9]) by BYAPR10MB3366.namprd10.prod.outlook.com ([fe80::baf2:dff1:d471:1c9%4]) with mapi id 15.20.8335.010; Wed, 8 Jan 2025 22:23:20 +0000 Date: Wed, 8 Jan 2025 22:23:16 +0000 From: Lorenzo Stoakes To: lsf-pc@lists.linux-foundation.org Cc: linux-mm@kvack.org, linux-fsdevel@vger.kernel.org Subject: [LSF/MM/BPF TOPIC] The future of anon_vma Message-ID: Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-ClientProxiedBy: LO4P123CA0359.GBRP123.PROD.OUTLOOK.COM (2603:10a6:600:18d::22) To BYAPR10MB3366.namprd10.prod.outlook.com (2603:10b6:a03:14f::25) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: BYAPR10MB3366:EE_|IA1PR10MB5946:EE_ X-MS-Office365-Filtering-Correlation-Id: bb25c87c-d211-4134-1dcb-08dd30330ed2 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|1800799024|376014|366016; X-Microsoft-Antispam-Message-Info: =?us-ascii?Q?CasEI4FKmWzQZ5oDujr9SOtN4P/AMWcBjTeqYz7czLP+EAIdvCLdrKa1AJJ9?= =?us-ascii?Q?ZCzIjW39mnnLeehyVrXPykZInaROocMWw1MFdDp2UEMpTTFHq4uKIAH37nhG?= =?us-ascii?Q?4iov1EeFQ5kb2jObakllG8neQcehpVH9HGfqHdyEymcZZnrRxlJ5y3Wd9++j?= =?us-ascii?Q?nkL9x9qdhEkXkUQZbQNm/ypallc7aaJm/gb3EN1D9rjYQl2kdIUwlCRu5cgD?= =?us-ascii?Q?fzUCQK73uzhSCy0srX7h5qUUFotgmbc7EZMt92jMFrkGmewkzImwDyC7yTTS?= =?us-ascii?Q?zeL0DOCbvPA/9CbonIC0rsr6wqgjtRc58qMUCAnFM/2gzk14Nz7N26XlipdV?= =?us-ascii?Q?/wpcGjYdhIK31z4n0xkM66cpmPv7aG4KMBM/gu+DcvNKQGZ0vFS3lRWQEcDX?= =?us-ascii?Q?mxWh/Zh60qMVaxcz9zzKjTrND7+G+ZSckgwJoTK4cKlg1K1PGl7vmvTtNO7o?= =?us-ascii?Q?xdVGhr+Gkq4x/iedv/jUEQlDyXxZ+4Ywgdmmcd9/D9Xz00AFbLt5xSQDQd+B?= =?us-ascii?Q?xx6x8knRh9p1Su2gidtQ1IGawOkYZEue5SS+NaavowHLvxMCEu1JbLAi4myg?= =?us-ascii?Q?/NeqFvACVZIEUgPWC3Lzi8V2zsTn0y8a4z8Nt8WQtzd87KJOxFNPmb1I1yHh?= =?us-ascii?Q?yFfdE32QjUUMzgukMes03M26+ly6EWEuDqWgiPQF26mBwi+IVAM2Pl1Lb8/c?= =?us-ascii?Q?CKMXiIk1TP1td2VvVry1GOyZq1cVgGiJxiYMfEyu3owXd1+vqg+WXzQk+GsC?= =?us-ascii?Q?5Ep492TNb4SYZFZ/SS7SbaterrUHvIC7y3u1CnhjgKFG33wRnQJBkmobUK+Q?= =?us-ascii?Q?/bPg9BGxdOu1BM8PlSXbgujIJgSRq8W86IUE3OClbAfern5Pu8tAah20ECCv?= =?us-ascii?Q?AYorW99gu1Gre+lMjYR0lv8MfQ9Ium5z3PorWOhScz0rJ/0tEzV9T8vEzsem?= =?us-ascii?Q?qinAtFi9sbAk561UO/23VQeHwUAhu9xgUYVxzI4GE1bysY/wmvRbRNaSVOCx?= =?us-ascii?Q?7RFzAaCDohDJPpXUwbeumpuNGz2yOOUl2HqjaxNTDY4CnE2is3+xXx9w+rjL?= =?us-ascii?Q?4GLwRK+ZeRRTFD1SUwd72ctDI0D+m4jgqB9xYRy2/+B+BMDWRXmVcANhm4eg?= =?us-ascii?Q?2t2sVzqBCEGMQPpHO/nezcjxryp9ArBrMZjuhG2jsUTzXTQbilU6+FIeF19h?= =?us-ascii?Q?5ZupWfgHIKFxfZmSvNE4uL/bV9GTWhxK7IK5JPcmhOM7TEzkG/u3TDn3NPaQ?= =?us-ascii?Q?j2oC8vqDrwqwj9AweY+QwokR7Vd6fmP6Mvw6pY415XgCO3MJ0brHhyn9JcoW?= =?us-ascii?Q?YBKY/Nrj2tiQh0Krf2Pooz52Yo99k4CZnDj+/6EA94BC0QdKK9rw2GK/DieK?= =?us-ascii?Q?1UFA+dpmKglt1OTLDd9wjIkQXI1i?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:BYAPR10MB3366.namprd10.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(1800799024)(376014)(366016);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?gmXptBsXHMgJdQ+bzW0u/tieR83H2iTFOaVzHVrDgrocxEhxtdYTsY2Am/XW?= =?us-ascii?Q?CeNKIy4+Vxzo+tJRBurCIw8cXexJ2YbEeftap0Y58BdjDQ8/5Z+uuBBPRD8r?= =?us-ascii?Q?9ENseBgTASi7oUHVxQh2VGaMdgZDSVePB790ARU3nT1TtESygC5sZajvD+vu?= =?us-ascii?Q?r5/J9IJdUZk1B9BzEjQOyzA3KhNl2LZRDszhmz+WVkJeTp7mMqUlgiLAVwZr?= =?us-ascii?Q?MX/hJEZAn3UmS99S6JNJ8p6873FAPOqRu3+6slH81Cn8LjP3gp5VHYCgHsJo?= =?us-ascii?Q?TPs6IWqXbrcJshKny+dIxVjOFt7Ka07ZEc8ETHSVooaPgYGT5FriKdMaTTdz?= =?us-ascii?Q?8RtucAaxHbHFH3C2KVBw6g3+1myRI9F3XHEtbIZD0vEunOp+Yd3lRXdId42Q?= =?us-ascii?Q?xgDJQARpx6VBkZqQi2pMeuIKNVk2I2ImSOTBdPhahtsVymBlFDODbFZrKooA?= =?us-ascii?Q?UF+rRO1BqonsuoIXFIw0iIGQv0jYgEEVlT3N50Z4OlwmoMVtZTZjAF5q7Znr?= =?us-ascii?Q?wU8l8nW20QIgVclltJqLmnOQeXvhi5QNztqH3kJbGCxssL0JsHL5Tm/LFZhM?= =?us-ascii?Q?+Hwcvde6H05aIffNaeDMrKzaP5zKYFQ17HyZBKdXG+ImUPup2KPN9g4w/vyi?= =?us-ascii?Q?Q0j6mQZatbWV3jV+soaNf51sfFW5IplwlaGlP9KLMpRXlIm/l1nqIKcpZryX?= =?us-ascii?Q?Rk6yAultbvW1RGviWkL7O0aKYUXJ0yR2ZzHeaiVFhWIR2UmPcZ8dBWtAo+i9?= =?us-ascii?Q?ZCRhEpLx+VmF8nAoa2zuNl86OVLUXIAgNL/OWfs/8hBJifDejdrxWL4aXucX?= =?us-ascii?Q?2Wu3nqiRNUkbpM5kc3kDiGhJBGbSwPBRXtch3kgMCpM4tin4JpvgJfTddfqj?= =?us-ascii?Q?GEO+x1YrPgfDAQzIhJqROgyDGm1pxgbFeuMUhkGHATWkcenhE8oAjpzUlUFx?= =?us-ascii?Q?olrIFxKsmHK/Ilz/HC7im265EaIdGjlguA58Ct+pDF+CmwasaQPOtQpEIsVS?= =?us-ascii?Q?SGAgdKMTpCu/xBwUECJeNK5sJ2xF4331CCPF21uDeBMZBcLic7JcPDsPa600?= =?us-ascii?Q?o6PLBLHpki9lomurvCRkBM0Pr54dNY85y29Jy8p56LxdbDEaziNbu7IcAM1L?= =?us-ascii?Q?J4rvn0iim8c7uPGg7SXItgGI6vXVP86zejzFdAETLbG7nsNDPzx/L2cZSOHq?= =?us-ascii?Q?r/Mnl3OMp9crDpkj7S4pCbUrtQOkbgUp2Tvs04mr60wkbXhKHrnTOk8UYGoP?= =?us-ascii?Q?NzrLw4nCVrptGp3GScDXf437wiQrzrk07EgdUT1LXHO2BaIgTWzawCdGA5+x?= =?us-ascii?Q?g9W0pBGmMYcB7557KWpHZUKWQOFcQXOGF7+BPrOsgY4+K355l6VmHLQ/VR5/?= =?us-ascii?Q?G8EK+V7/IUCyrti+zK8vfExc3TLuFQWAib05IbnTmseOOSjMA0OdmADOPg+l?= =?us-ascii?Q?tUY62VAMaekFaPs5SMuneNv1opkTbPzhxstVIJDH/kMIu+vwlqzzMw15AdC5?= =?us-ascii?Q?DD+n884qR9qTiGr/qBDcwTZf6F6mIA6YhbK+Wt6Rekyc1FwF+slMDWlTAXoT?= =?us-ascii?Q?eLakQ/GcKkyXlwcrQNRG11cXCgbzn3PEgP3yAQMMq3D3sK1coCtA7VuBd/Iq?= =?us-ascii?Q?oQ=3D=3D?= 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: bb25c87c-d211-4134-1dcb-08dd30330ed2 X-MS-Exchange-CrossTenant-AuthSource: BYAPR10MB3366.namprd10.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 08 Jan 2025 22:23:20.8212 (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: bpWrTleR7vUg0kszXyZTyzBg1dLg9Ejdw1KjcQX5LtoEx+Aok/vdrz3EDf+lmZA7fHxvpB6hxZ+KAPe4sKM3IypYhuGmf+a9E6XOHDywASw= X-MS-Exchange-Transport-CrossTenantHeadersStamped: IA1PR10MB5946 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1057,Hydra:6.0.680,FMLib:17.12.68.34 definitions=2025-01-08_05,2025-01-08_01,2024-11-22_01 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 phishscore=0 malwarescore=0 adultscore=0 mlxlogscore=978 suspectscore=0 mlxscore=0 spamscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2411120000 definitions=main-2501080183 X-Proofpoint-ORIG-GUID: 5C1infki90WSdjeFaj9-_hTPrbNN58Pi X-Proofpoint-GUID: 5C1infki90WSdjeFaj9-_hTPrbNN58Pi X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 8DAC91A000F X-Stat-Signature: fnyi8743p5qj3daqwzbsxfy17crx4kiy X-Rspam-User: X-HE-Tag: 1736375007-107776 X-HE-Meta: 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 29vTRdeQ 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.418027, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: Hi all, Since time immemorial the kernel has maintained two separate realms within mm - that of file-backed mappings and that of anonymous mappings. Each of these require a reverse mapping from folio to VMA, utilising interval trees from an intermediate object referenced by folio->mapping back to the VMAs which map it. In the case of a file-backed mapping, this 'intermediate object' is the shared page cache entry, of type struct address_space. It is non-CoW which keep things simple(-ish) and the concept is straight-forward - both the folio and the VMAs which map the page cache object reference it. In the case of anonymous memory, things are not quite as simple, as a result of CoW. This is further complicated by forking and the very many different combinations of CoW'd and non-CoW'd folios that can exist within a mapping. This kind of mapping utilises struct anon_vma objects which as a result of this complexity are pretty well entirely concerned with maintaining the notion of an anon_vma object rather than describing the underlying memory in any way. Of course we can enter further realms of insan^W^W^W^W^Wcomplexity by maintaining a MAP_PRIVATE file-backed mapping where we can experience both at once! The fact that we can have both CoW'd and non-CoW'd folios referencing a VMA means that we require -yet another- type, a struct anon_vma_chain, maintained on a linked list, to abstract the link between anon_vma objects and VMAs, and to provide a means by which one can manage and traverse anon_vma objects from the VMA as well as looking them up from the reverse mapping. Maintaining all of this correctly is very fragile, error-prone and confusing, not to mention the concerns around maintaining correct locking semantics, correctly propagating anonymous VMA state on fork, and trying to reuse state to avoid allocating unnecessary memory to maintain all of this infrastructure. An additional consequence of maintaining these two realms is that that which straddles them - shmem - becomes something of an enigma - file-backed, but existing on the anonymous LRU list and requiring a lot of very specific handling. It is obvious that there is some isomorphism between the representation of file systems and anonymous memory, less the CoW handling. However there is a concept which exists within file systems which can somewhat bridge the gap - reflinks. A future where we unify anonymous and file-backed memory mappings would be one in which a reflinks were implemented at a general level rather than, as they are now, implemented individually within file systems. I'd like to discuss how feasible doing so might be, whether this is a sane line of thought at all, and how a roadmap for working towards the elimination of anon_vma as it stands might look. As with my other proposal, I will gather more concrete information before LSF to ensure the discussion is specific, and of course I would be interested to discuss the topic in this thread also! Thanks!