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 E90EFC5320E for ; Sun, 25 Aug 2024 06:42:24 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 79F106B0382; Sun, 25 Aug 2024 02:42:24 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 74F8C6B0383; Sun, 25 Aug 2024 02:42:24 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 57B586B0384; Sun, 25 Aug 2024 02:42:24 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 3442E6B0382 for ; Sun, 25 Aug 2024 02:42:24 -0400 (EDT) Received: from smtpin19.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id AC265140DC1 for ; Sun, 25 Aug 2024 06:42:23 +0000 (UTC) X-FDA: 82489823766.19.6B13DA6 Received: from mx0a-00069f02.pphosted.com (mx0a-00069f02.pphosted.com [205.220.165.32]) by imf29.hostedemail.com (Postfix) with ESMTP id 4AE7B120004 for ; Sun, 25 Aug 2024 06:42:20 +0000 (UTC) Authentication-Results: imf29.hostedemail.com; dkim=pass header.d=oracle.com header.s=corp-2023-11-20 header.b=k2qX4x0V; dkim=pass header.d=oracle.onmicrosoft.com header.s=selector2-oracle-onmicrosoft-com header.b=iJVba8rm; spf=pass (imf29.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=pass ("microsoft.com:s=arcselector10001:i=1") ARC-Seal: i=2; s=arc-20220608; d=hostedemail.com; t=1724568098; a=rsa-sha256; cv=pass; b=tFmAH43BC03mAqeBAXR8NIGAoSqLVsTQgs2eDg6XLr8hCaYZWSY7IXkSlrV4iogZQomWs+ 2jXiE61Otbi6hXh7ImMDfcA7PW8qka+UVpq37vF0dt/NWvjU/t511+27h9xuNwTWuh9aZ6 pEjgT1DFVeUJ3RlBuLw/0wvKLSJtNW4= ARC-Authentication-Results: i=2; imf29.hostedemail.com; dkim=pass header.d=oracle.com header.s=corp-2023-11-20 header.b=k2qX4x0V; dkim=pass header.d=oracle.onmicrosoft.com header.s=selector2-oracle-onmicrosoft-com header.b=iJVba8rm; spf=pass (imf29.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=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=1724568098; 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:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=Pxn/PMLdU/i9VGCaIrzPUyPIFPlZccGcgjDX+R5mYfE=; b=q3JpKinvKJovCrEnmH/fcmuaqfCbwGfPFA7X3vqgKM+dCmHo9wS5ReLtHAycru6AESVEtg /KIG948Kt+btatvGUYzkpSMhXwa+cjNM8m6RioyHMLfRHmKqpuclmvkJkHBQNPJcmIOsPQ 7XTZu2GbNIddDbM2g3zt+Bk+8F6Tcm0= 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 47P4qx1d001586; Sun, 25 Aug 2024 06:42:18 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h= date:from:to:cc:subject:message-id:references:content-type :content-transfer-encoding:in-reply-to:mime-version; s= corp-2023-11-20; bh=Pxn/PMLdU/i9VGCaIrzPUyPIFPlZccGcgjDX+R5mYfE=; b= k2qX4x0VBzF2pX+u2uHDP7D/t0X56y/oDWFwe7O7OpTfcJjr52OvcmYlZ46iHIZV F0K+3xqgZd9nEBQcaDeF5ajeJBUciv+Qv4hldt1jfI/i0MjVsOThY52Fi+85Ztcj 83I2GSmPCdIMKRl12KieMgWU3gn0bW2aem+q3riJT4xhRG/8v7cpD2H+CN0c126D DklIjObcg3kSGuTVoOh3qKbz6MvuOhY4cAQGT0dt+Hfgs+BhUMOX3qvUc2lkNfEc Gr/c9PJTVRKi2B86aXotT/AW9Tc3tArGVzvBypLc+Eqe1MdAicPQOZQXxk1Zp4VR YkmtqhMP76Cp08J/QIXgTA== Received: from iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com (iadpaimrmta02.appoci.oracle.com [147.154.18.20]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 4177hwh1s8-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Sun, 25 Aug 2024 06:42:17 +0000 (GMT) Received: from pps.filterd (iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com [127.0.0.1]) by iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com (8.18.1.2/8.18.1.2) with ESMTP id 47P5WIlw021512; Sun, 25 Aug 2024 06:42:16 GMT Received: from nam12-mw2-obe.outbound.protection.outlook.com (mail-mw2nam12lp2041.outbound.protection.outlook.com [104.47.66.41]) by iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com (PPS) with ESMTPS id 417xj712pt-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Sun, 25 Aug 2024 06:42:16 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=S/ILtrnMlX/nCdQI/k2FLn2wxMWGHl+mEG43e3NbUcijRJe9kyx0RmXCDmezW4luTp7YVnU4VDB7pP8Wwe/nebABrBhOeP9vLMPmHRuwRiCeSHyzHiKXcPqhGeMTBsFXOdy+LHm8h9U/2Je8FyqMRsmg15/XXB4giWhj94Bjku56o40zT+UYAAiIkqi/4Aw1mOYzXpURVaHsg31wpxaaId46SxHNefrP9eWKiNiT9uggvm2UfHXiyJS1A7gYx14Eal+32C/xHcjBQPfTrBbLBydBCG9jfJxAgunwlPrlPYew9SNeN3zHr4FrC49WX/iDG+0WGQfg3beTHXlXx7njXA== 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=Pxn/PMLdU/i9VGCaIrzPUyPIFPlZccGcgjDX+R5mYfE=; b=x6neS5JlMvezgdkeaVasghF4B9GAVwbXMuiD4B3eqSdPZUNqhDSeDdgIH/qR2iU50UeKF95ImNeaDnEYkuQ3f97R9LRmJ7914n74JyJMmknAxrC6iMzXH+Y4xW1bzM6tbCqEiAxI++BwyWjkedxwMlPxQRLN2iRVEJcPqgR4jgwiUwX1vbRpGsb4HmO8BS55UJvfauTe6rTFJbp/s8YoM/kcQ8ho2lKP747EG8kmVPyqkpCaA6ytCOgPSXeQx3NeKz+GPV0GUqj7RH6AFmhQ0oDPhtXvuier/rIyPeg47TI2KR8KcbWDnm1+tkbktjWJr2/ou9K0Q9uxpWSUzweW+A== 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=Pxn/PMLdU/i9VGCaIrzPUyPIFPlZccGcgjDX+R5mYfE=; b=iJVba8rmaQd3Cv2Jg2/B8VXNWCDCOshJyVFONaB3gU03g0pr/dhjrSRDf2gawCKXlTxvnoOCrkFHsPYUYPwG8/IfzoV77g3VI1t4z6sXGc0lD/56s2akreKHj6p73Qe47XgkUx0mmO86SUiUAYThyizgKH9GbACxpkQ8IqJVPAI= Received: from PH0PR10MB5611.namprd10.prod.outlook.com (2603:10b6:510:f9::16) by MN0PR10MB5957.namprd10.prod.outlook.com (2603:10b6:208:3cf::19) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.7918.9; Sun, 25 Aug 2024 06:42:13 +0000 Received: from PH0PR10MB5611.namprd10.prod.outlook.com ([fe80::d513:a871:bbf9:fce2]) by PH0PR10MB5611.namprd10.prod.outlook.com ([fe80::d513:a871:bbf9:fce2%6]) with mapi id 15.20.7918.006; Sun, 25 Aug 2024 06:42:13 +0000 Date: Sun, 25 Aug 2024 07:42:11 +0100 From: Lorenzo Stoakes To: zhiguojiang Cc: Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, oe-lkp@lists.linux.dev, lkp@intel.com, opensource.kernel@vivo.com Subject: Re: [PATCH v2] vma remove the unneeded avc bound with non-CoWed folio Message-ID: <1109aeab-fd4a-4c83-a110-04d01177d72d@lucifer.local> References: <20240823150206.565-1-justinjiang@vivo.com> <73ad9540-3fb8-4154-9a4f-30a0a2b03d41@lucifer.local> <4dd13a4c-e968-4a3a-98e5-97f28036deff@vivo.com> Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <4dd13a4c-e968-4a3a-98e5-97f28036deff@vivo.com> X-ClientProxiedBy: LO4P123CA0653.GBRP123.PROD.OUTLOOK.COM (2603:10a6:600:296::23) To PH0PR10MB5611.namprd10.prod.outlook.com (2603:10b6:510:f9::16) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: PH0PR10MB5611:EE_|MN0PR10MB5957:EE_ X-MS-Office365-Filtering-Correlation-Id: eac8ad0c-5467-4f88-8552-08dcc4d10da5 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|366016|1800799024|376014; X-Microsoft-Antispam-Message-Info: =?utf-8?B?b3g3aTJ4ays4NXN1Z1Y0cjFBWENPcnJPOEJBaFFtZ1lhQUNOQm1OZlFFZVI1?= =?utf-8?B?TmdPay9JSFdVMUxLQU9BekJwZVRUNmZ6Mk52Uk93T0xjelJPdFlBNlVtaDVF?= =?utf-8?B?am92TWszeFQxc1I4U1F1aXdsdGY4R3BiWWlpanorbFZwRzBhYVdXQjBRdktm?= =?utf-8?B?M25pdzZIUmFxbThVV1BSZFI4Z0crcFM4MDc0b2d1YnFKTUU2cGpqMkpNUEhX?= =?utf-8?B?VkdCUDh1WEtBSzE1eHZJMEZ6ak0ycjJpZU1Tb2xkb2VocDhOb0I5bSs3aGdC?= =?utf-8?B?WXRPa1lLRzVTaGg1UmZVTXVoSzhyUFYzbWM1Slg5UHlVM0ljRm5DL0VaYWtH?= =?utf-8?B?NFlPQUlWcDYxaHZPZXY4Q2FUZlFLSjFBTzRSVzZRSmhJS3RkVzZWSEFIRG01?= =?utf-8?B?bzRFV3p4dHlRQlp4MXQ1VzN5VFcwWkVTaWpzem1uUnhUVVhPbHI3R09rdmQ0?= =?utf-8?B?OEZ2VDUzcUUveXVaZXJlSzhYMzVhcWJ0ckFBQTRuRW1jTDBaVWwvNFZMT2tp?= =?utf-8?B?dTVwaFJycGs0R3F0UlNKZzgwM3MrQjB5dFJNQTVkRVcvUjR4L1BLYlNrRzFp?= =?utf-8?B?SjQvZUhacHFFaXVEdThCTlhzd0NsM245amhPRjEweDZTWUZDd2h1QXhPQWsz?= =?utf-8?B?R0JiaVZOQm5qVXl3aXYraFpMelJTMVJTQzlONVorVktaeWYzb0Y2WDkybERz?= =?utf-8?B?WTB3RW5NWUdhRTF5WWt0Z0VnRHR6ZVlqajZwaWR5NE5wWGZXWE9jQmVZbk1r?= =?utf-8?B?K001K2x3MHZkc3VKamk0dDJZUVpRSXVQcmZnZE9yVXBWMU0rSGNWczVVRFlX?= =?utf-8?B?RTV6UTU4bnBqZ0Z0dHZ5OFprSU5CQ3kvbnJlTDQyZ2tGcUticXIxb0hNR3d6?= =?utf-8?B?TGEvekIyRkxXdnl4Z3R1YXZBdHdFaElvbjRsOGZrMmFPd295djBCNklUbFUy?= =?utf-8?B?Yy9wZS93YVpZM2RPM1k2ZmZUUGt1c0ZpM1ZjTmtudHJLTnJwSEtNOVNoNDIy?= =?utf-8?B?dG1vdGo2RnlSU04rTm4xdXdxSmFzWE5FNjhwOFRxTjMwaENJNkpUdEkyV0dE?= =?utf-8?B?UFlwYlZVSXhnMWJuSmpNRU8veW4yZXRNMFhyMm5ubjZoTStwY094QnVkSlBl?= =?utf-8?B?QzNsYzlQdll2SzJmSEhhVjdLY2lVYTZZYy9sVnpMOHVEcTdCK2xUQWwwZFJG?= =?utf-8?B?L3pwNXVqNVRYZXBXYzV3Zkk2VTA0YitGclRDbFRzUUFIV25OTlJyc0N4SHEv?= =?utf-8?B?dTltRGoybTZXQTRNbjhTNUxkVjZQS1hRZlNJWVdtWk5TZjdQNytxSnlpWmJ5?= =?utf-8?B?OW5LblhiM3BKZVVRQXZwNkZCZWpuaDkvVUt1cEFudUFINlNnN2RVWjVibEVx?= =?utf-8?B?TG5GTUpSVmVPMUhkbWtFNTNQYVc0eEhvd040d3VhNkVJOS9RMGN2TW9ZTjM4?= =?utf-8?B?VC9qOFVXY0dRR1FocXhOR2ZQVlB5RGF2S0todVVLMmFUYjVCUThHZWwyM2Fr?= =?utf-8?B?ald3d25qQS8xenpsK3FHVjdEajU0S1o3czNUVFFjY0VtU3d5MytpWC9wLzF3?= =?utf-8?B?WW0xVFFIN2VhSjBLTUw4eXdGRkhReHg4OElJVEVvSkNlMDFRK0h6V0Rtd1Ro?= =?utf-8?B?UW83S09kaFd3UGZPeXluWXBVL01vSVJrMlo2d1JIMVdXQVhkQjQrQktCN0pP?= =?utf-8?B?VVVwcHF3WllyMENJdFpDL2JwMVhUN29ZeFlONG8rNlpBMTlhbHptckpCLy8x?= =?utf-8?B?aG1nZDVZZk1UN2Z6MkJISHoxTWxqcmQxUmFORnJ4ZDAvYVVyZXdwRVY2TjA3?= =?utf-8?B?dnVDU1JTMFMrSWJDMXRxZz09?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:PH0PR10MB5611.namprd10.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(366016)(1800799024)(376014);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?cFJNRUlZemlhMDBQRGR1R2lqNHJPazBSWWpaK0V1Y3dlV1B6Rmg2MWpJcXN2?= =?utf-8?B?T24yaHlNYnJCdzg1VVNtUnBIVmIzYURvRWduMVowM21jMTltakE4a1NmOEJi?= =?utf-8?B?OFVWdUh6M1JROXFlZmV6ODN4TEg1bG9lS3h2eWtuaXh6S2tmUTFjSWpNcUhq?= =?utf-8?B?cG94Z0pwdWZ5d2hoMVFjM0JxRnR1a1dNZjJwcVR4ZTNXc2kxeGRYNFQrQWVJ?= =?utf-8?B?d0s2cFY5VDVmamRPUkFmVHY3S1d0MUdqcUVSRW1xazJZdTBYZ25WeUErWmNj?= =?utf-8?B?RkQvVkx3MkVMZmlpR3hsMHJWYlBFTjBGdXZ0K0pZclVhL0RsS3U4VXUybk5H?= =?utf-8?B?R3ZuV2dwTjZJYTFQVUg2ZWFZcE4vN3lxWFZJVVYzWVdUaXZxQUw5VFpXQjhi?= =?utf-8?B?MFVMYzc1b01oVkJ5REl4V2c3a2FsYWthRFp0eTJSUGlWZllsZ3l4OElRMFBO?= =?utf-8?B?Q1dCM1BJaE5TSEZmalY3V0dhc1M3alRrSEZrVG4xMTJQdW41QkFTa25JU2I1?= =?utf-8?B?VHhiQnIrTnJibDMwSm1VVWhsQzZzUGJBVGtGMk8zSm1HdUFqeVdkVVp1Tnc0?= =?utf-8?B?NkxXby9XM1JkSU1adWxJanZDMjJ0OFFkbGNCeGxMWGF4WFcxS1FGWWpPWkJo?= =?utf-8?B?d3J3QnpLYTFYRVJYRXkzSkNLRnkybHFYQ09pSFo2cXZHU0t3V1FqR0U5Q1I1?= =?utf-8?B?Qzh6dmo1NHk1S0hNVzJJdGIwbnZMM2I0OVdwazBKQmRnSnlJUzRFQzVwcUx2?= =?utf-8?B?cUlvWElmRmR5WG5WeXZLYU0zQzIxem1tcWtpa1lKMWFHcnA2ajJiS3NhSHhy?= =?utf-8?B?MUtlZ2hUL3pVTEpTbHc2V3JBLzB1bmdLdURVRUN2ejBCYnNIV3h3ekZWOXc4?= =?utf-8?B?V1BhMUNIaFI2MXI4T3BjUkNrd3ptOU5CLzBQMmdNNDdHY2VvTFV6QW05ekRX?= =?utf-8?B?M0Z1MWlXQ2lpWTRCeWpIT0pPWWhQTGFHN01PWmgvVzJIOHk3ZElMTFVFZ3hj?= =?utf-8?B?U0JQSWV2azNTTzdZS2UxWWFmSDduUXFCNThidTBmSTI2S05jSjhOT05kMStN?= =?utf-8?B?QUdwR2NZT2ZDRWtVWGdNVXFLYTc1VWpOcjlBdE5KOVBtRWhGNnJjdTMvQ1VK?= =?utf-8?B?d1l2V2c4clNtL1ZUL3JCUXNwZEVXNGU1ZDAvTkJESC8vcEJSTGRFcW5sSnNV?= =?utf-8?B?ZVY5d1V6dG5PZXJHSjRXKy94TFZrYnBHQThYa3JIZ1p0blBaQVMybUo5dGFT?= =?utf-8?B?S2dScjJIYUdhZVJDTS9XVHAvYmdBb1FiaHloSkNFaWJVdDRKM1RENk9BbTVQ?= =?utf-8?B?dm5sdUNrZkVVS01zMzFZTE1Db1AvT3NGcVYrUTZEbnd0UTNxNVF3WEJxNG9K?= =?utf-8?B?MVY1OFRISUVXbnphWkhxaGRMS1RKSlZkZ3JCWFRsQlRnc0ZyaXFHU0hZbUNj?= =?utf-8?B?MGVwNCtUVFVUMHFtQ3J4aWZ1UUgrbGhNVUpEek5saHFqc1B1Y2VHODdvTmZW?= =?utf-8?B?N1A0cGQ2Nlk5aHQrdUQ4U1RaQXE3ZU45dDRSN0RNWXA3Vk4zMDNkY2VLcDA4?= =?utf-8?B?M3BJS3NSbXM4WGxjdGU5cHdJOEJaL2dVMU5PdElLSXlIcGsxT1BGbzdYTE1T?= =?utf-8?B?ZWdPQjdkV0lPcm54L3ZoTWsxS0FWSGFsUXU5V091bTRZQmdrYjNwQXdXM0pB?= =?utf-8?B?RXZEUW81ZlFaSXFNQ09HTklQcmJiY3NHNXgydy9hb1pkY1ZtNkRtV3R1bDAx?= =?utf-8?B?L3VWUW5uekN3UjZVcmFVamxLZTRTOS90TWdhZStPK3NOQ2JDa2JJeUpxYVE4?= =?utf-8?B?Q2szN1QvUG9KVDFnc3lzdEVJMkpyQVdzRjJ1bkUvWnBWdUV5N3YyZHcxSVdo?= =?utf-8?B?U000TDM4eEI4RUkyQlJ1V2ZLdHA4dWNiVmZNNi9XZXlIakJpSnF4S3VQM3Az?= =?utf-8?B?cUk3V0FoMXpqYmM0dHJkOS9KRWU3ZnVzN0d6UFhWaE9neEdPSytBM1FDcnVE?= =?utf-8?B?d0ZGUmFqZlBlUWtsczR1WEdEVWtyd3pPbitvWkNQTmJxRENhSlUwZXRrVDhz?= =?utf-8?B?ZVArTFRadnZmcFVjVUdWOTZoR0xWczd1ZkMwMXZvOXpGQ2ZXQzZtTWZqcSsx?= =?utf-8?B?SUlrUGUzTkVoZ2M3b2FhMzF3Mi9ucjZyaU1EVkUwc2FzUld3aHAyVmc3eU8w?= =?utf-8?B?M2c9PQ==?= 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: eac8ad0c-5467-4f88-8552-08dcc4d10da5 X-MS-Exchange-CrossTenant-AuthSource: PH0PR10MB5611.namprd10.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 25 Aug 2024 06:42:13.8159 (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: Yzla+CHDM7qjL1qzSV/eKrB/1PBrUkgRZizubBcFcjg+Y30a7BFuPK+ic5OGG7mooNV6mvEXn6bdCrP/njSCbAcxrk6nK02KS0eTnVkBr3E= X-MS-Exchange-Transport-CrossTenantHeadersStamped: MN0PR10MB5957 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1039,Hydra:6.0.680,FMLib:17.12.28.16 definitions=2024-08-25_03,2024-08-23_01,2024-05-17_01 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 phishscore=0 suspectscore=0 adultscore=0 mlxscore=0 spamscore=0 mlxlogscore=999 bulkscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2407110000 definitions=main-2408250048 X-Proofpoint-GUID: hzNQV3afMRO2NTJcWUyG0uMmzqU6gdRu X-Proofpoint-ORIG-GUID: hzNQV3afMRO2NTJcWUyG0uMmzqU6gdRu X-Stat-Signature: r9zkfen45ttywthu4uyejbe5wd16c8ob X-Rspamd-Queue-Id: 4AE7B120004 X-Rspam-User: X-Rspamd-Server: rspam10 X-HE-Tag: 1724568140-312576 X-HE-Meta: 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 R5X2qZnb 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.005353, 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 Sun, Aug 25, 2024 at 01:06:40PM GMT, zhiguojiang wrote: > > > 在 2024/8/25 0:26, Lorenzo Stoakes 写道: > > [Some people who received this message don't often get email from lorenzo.stoakes@oracle.com. Learn why this is important at https://aka.ms/LearnAboutSenderIdentification ] > > > > On Fri, Aug 23, 2024 at 11:02:06PM GMT, Zhiguo Jiang wrote: > > > After CoWed by do_wp_page, the vma established a new mapping relationship > > > with the CoWed folio instead of the non-CoWed folio. However, regarding > > > the situation where vma->anon_vma and the non-CoWed folio's anon_vma are > > > not same, the avc binding relationship between them will no longer be > > > needed, so it is issue for the avc binding relationship still existing > > > between them. > > > > > > This patch will remove the avc binding relationship between vma and the > > > non-CoWed folio's anon_vma, which each has their own independent > > > anon_vma. It can also alleviates rmap overhead simultaneously. > > > > > > Signed-off-by: Zhiguo Jiang > > > > NACK (until fixed). This is broken (see below). > > > Hi Lorenzo Stoakes, > > Thank you for your comments. > > I'm not seeing any numbers to back anything up here as to why we want to > > make changes to this incredibly sensitive code? > I added a debug trace log (as follows) in wp_page_copy() and observed > that a large number of these orphan avc-objects still exist. I believe > this will have a certain redundant overhead impact on anonymous folios' > rmap avcs, so I want to remove it, which is also the most essential > value of this patch. Sorry nack to that idea unless you can provide actual _data_ to demonstrate an overhead. And even if you did, given the original patch was so completely broken, and in such a sensitive area, I'm going to need to be VERY confident you didn't break anything, so we're going to need tests. > > -- the vital part of debug trace patch: Thanks for providing! Will snip for sake of making it easier to reply. [snip] > > > > Also anon_vma logic is very complicated and confusing, this commit message > > feels about 3 paragraphs too light. > > > > Under what circumstances will vma->anon_vma be different from > > folio_anon_vma(non_cowed_folio)? etc. > In anon_vma_fork() --> anon_vma_clone(), child vma is bound with parent > vma's anon_vma firstly. >     /* >      * First, attach the new VMA to the parent VMA's anon_vmas, >      * so rmap can find non-COWed pages in child processes. >      */ >     error = anon_vma_clone(vma, pvma); > > When child vma->anon_vma is NULL in anon_vma_fork(), >     /* An existing anon_vma has been reused, all done then. */ >     if (vma->anon_vma) >         return 0; > >     /* Then add our own anon_vma. */ >     anon_vma = anon_vma_alloc(); > > new anon_vma will be alloced and filled in this child vma->anon_vma. > Then during CoWed in do_wp_page() --> wp_page_copy(), this child vma's > new anon_vma will be different from folio_anon_vma(non_cowed_folio). Thanks for the explanation, but I was suggesting you have to put this in the commit message rather than in repy to me :) > > Confusing topics strongly require explanations that help (somewhat) > > compensate. This is one of them. [snip] > > > index 93c0c25433d0..4c89cb1cb73e > > > --- a/mm/memory.c > > > +++ b/mm/memory.c > > > @@ -3428,6 +3428,14 @@ static vm_fault_t wp_page_copy(struct vm_fault *vmf) > > > * old page will be flushed before it can be reused. > > > */ > > > folio_remove_rmap_pte(old_folio, vmf->page, vma); > > > + > > > + /* > > > + * If the new_folio's anon_vma is different from the > > > + * old_folio's anon_vma, the avc binding relationship > > > + * between vma and the old_folio's anon_vma is removed, > > > + * avoiding rmap redundant overhead. > > What overhead? Worth spelling out for instance if it's unnecessary to > > traverse avc's. > I think this will have a certain redundant overhead impact on anonymous > folios rmap traverse avcs process. This is again nowhere near detailed enough, and again I'm asking you to write this _IN THE COMMENT_ not in review. I already understand what you're trying to do (I think the fact I provided a _working_ version of your patch as an attachment in this thread should give a clue ;), this is for the benefit of people coming to read this code. [snip] > > Again I question the value of this change. Are we REALLY seeing a big > > problem due to unneeded avc's hanging around? This is very sensitive, > > fiddly, confusing code, do we REALLY want to be playing with it? > Thank you for helping to identify mang issues with this patch. However, > I think this will have a certain benefits for anonymous folio rmap > traverse avc overhead. > > > > It'd be good to get some tests though unless you move this to vma.c with > > its userland testing (probably a good idea actually as Andrew suggested) > > this might be tricky. > This patch belongs to anon_vma rmap's content, and it seems more > appropriate in mm/rmap.c? > > > > NACK until the issues are fixed and the approach at least seems more > > correct. > Thanks > Zhiguo > Please see the attachment in thread for an example of a working version of this, this is sadly fundamentally broken. But you're going to really need to sell this a lot better, provide some numbers, and provide extensive testing and a much, much better test for this to stand any chance. I appreciate what you're trying to do here, and it's not totally crazy, but we have to be so, so careful around this code. anon_vma code is horrendously subtle and confusing (I actually had to reference my unpublished book to remind myself how this stuff works :)), so we have to tread very carefully. I definitely think we need ASCII diagrams if we were to go ahead with a new version of this. But then again I'm a bit of a fan of ASCII diagrams... Please cc- me on future revisions of this series, thanks :)