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 B317CC001B3 for ; Mon, 3 Jul 2023 18:49:50 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 52FC66B00E5; Mon, 3 Jul 2023 14:49:50 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 4DFF4280030; Mon, 3 Jul 2023 14:49:50 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 35A2928002F; Mon, 3 Jul 2023 14:49:50 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id 205E36B00E5 for ; Mon, 3 Jul 2023 14:49:50 -0400 (EDT) Received: from smtpin25.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay04.hostedemail.com (Postfix) with ESMTP id E52631A0746 for ; Mon, 3 Jul 2023 18:49:49 +0000 (UTC) X-FDA: 80971189698.25.7C31A11 Received: from mx0b-00069f02.pphosted.com (mx0b-00069f02.pphosted.com [205.220.177.32]) by imf28.hostedemail.com (Postfix) with ESMTP id 0CDD5C0024 for ; Mon, 3 Jul 2023 18:49:45 +0000 (UTC) Authentication-Results: imf28.hostedemail.com; dkim=pass header.d=oracle.com header.s=corp-2023-03-30 header.b=OZZbeyNz; dkim=pass header.d=oracle.onmicrosoft.com header.s=selector2-oracle-onmicrosoft-com header.b=MPqXelaw; spf=pass (imf28.hostedemail.com: domain of mike.kravetz@oracle.com designates 205.220.177.32 as permitted sender) smtp.mailfrom=mike.kravetz@oracle.com; arc=pass ("microsoft.com:s=arcselector9901:i=1"); dmarc=pass (policy=none) header.from=oracle.com ARC-Seal: i=2; s=arc-20220608; d=hostedemail.com; t=1688410186; a=rsa-sha256; cv=pass; b=ees+P1VvolStPisrHcOCp9WQmNWdsg8L/WnQ6cMic7eYzi3PJxeoUA03jcIf8n1fOqKvCu 00wa7/21drnLCfgxD6wk5tgzv0aowA5sIGkMtSHKnZCWUaHc9WrxveHFQVaszurWFYIs9k Vc1zS02RtzWubLi8c9kIZsxkF/hyHxk= ARC-Authentication-Results: i=2; imf28.hostedemail.com; dkim=pass header.d=oracle.com header.s=corp-2023-03-30 header.b=OZZbeyNz; dkim=pass header.d=oracle.onmicrosoft.com header.s=selector2-oracle-onmicrosoft-com header.b=MPqXelaw; spf=pass (imf28.hostedemail.com: domain of mike.kravetz@oracle.com designates 205.220.177.32 as permitted sender) smtp.mailfrom=mike.kravetz@oracle.com; arc=pass ("microsoft.com:s=arcselector9901:i=1"); dmarc=pass (policy=none) header.from=oracle.com ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1688410186; 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=pjFuUAlPCzAG7IidBiDVgOgqiX3tGSJKtdVV0MXdGSE=; b=iD+s4qQmGYj79ELS8B5JUUWuqAKQMiWy1tLiyzikj9hemcUQ/OtWyHskZCduuegSdNsksY aITo4Eb3pNNigZbafHuyM6cyb/x9z/M3qnICbAdDL98qI22TQ3B1BUlVhjrn2VXClGuOYQ D+MdBtsGIVzynEKqefBXQ4uR26wQFDw= Received: from pps.filterd (m0333520.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 363G82sN025208; Mon, 3 Jul 2023 18:49:34 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 : in-reply-to : mime-version; s=corp-2023-03-30; bh=pjFuUAlPCzAG7IidBiDVgOgqiX3tGSJKtdVV0MXdGSE=; b=OZZbeyNzYeHKDo3nPcwlmLNyLjkR8jKokrhCSUMPcRWnlXR/JtIrqpyTGM93fIq9C8/G GR0pBqBqEMLinP25nPGX8wG72ftN9cz4sgxAjhhO3/nCozSG2MJlN8bWXCDs2q9J0AV1 1jhxRC43gzmFfaJJlXoBeXFo74OEILF5R8G5/MTLs8K+x0HYflEKBuohGPLVFY5JQ6AY POm0qVUL9TDvY2nhC2ePDZViAze941EPbypxDwKQR1RM6aoRDf2R298R9D4xCcOZ+thE FZ6pS8XM2GbGcnlS6vnj1zT1xuEo+r5XfTeEPuAXoRaAu+UYnLw5Wmp3MiVnz19C2ygC EQ== Received: from phxpaimrmta02.imrmtpd1.prodappphxaev1.oraclevcn.com (phxpaimrmta02.appoci.oracle.com [147.154.114.232]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 3rjc6ck9h7-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 03 Jul 2023 18:49:34 +0000 Received: from pps.filterd (phxpaimrmta02.imrmtpd1.prodappphxaev1.oraclevcn.com [127.0.0.1]) by phxpaimrmta02.imrmtpd1.prodappphxaev1.oraclevcn.com (8.17.1.19/8.17.1.19) with ESMTP id 363H3DeR010875; Mon, 3 Jul 2023 18:49:33 GMT Received: from nam12-dm6-obe.outbound.protection.outlook.com (mail-dm6nam12lp2174.outbound.protection.outlook.com [104.47.59.174]) by phxpaimrmta02.imrmtpd1.prodappphxaev1.oraclevcn.com (PPS) with ESMTPS id 3rjak3p6q3-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 03 Jul 2023 18:49:33 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=V9xW+m0YkaSS9e1RIjWe2VOUEuks2eZ0XxmGJIL9kL19RidpAzYl2mLKUxRtuTd/d2q45wsXZLC1cydFrpavyy5+VsrRWOt5EcQ64EsgL7BTJ2pVdvu7Z5EZE7zhsmKNvY/QJoRDcHqRGsNodpwIKJD0eiC1K1udfb2HJJgfr/TDSXJSbGDgjrrQ1pgd53XVFLpy21Y1v3sXYbIo5Z6FfKrr4vdNn0kj1Y5D/QwjO1xbWS0k4qkzXr1ZCLtR0CP/eeyXy8Y/DhEB6FH01aXzg9q51ivYrl2kc/42vC+oVim3qAIk2o0Y6XK7nZpvWAbngcw8b0CVmbg+gp0N3O+lUw== 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=pjFuUAlPCzAG7IidBiDVgOgqiX3tGSJKtdVV0MXdGSE=; b=jjPmnj1rlJ4Hcm7UbwUSngu1JuCHbTGJ4WwLuYRp1k2UzWwpXsGeHvuKtkMbxRKXa1t6SQyIFohDohFdDsdUnS1YaCp81GEpefReNA1Ysl0Nnd/T7a+psG+vSJne9+F4AIVRsu0vXvpbbFcpi29bWDYYF023L9LBj/yPPcrMwT1/qHfNN4c5o2nMORXdf2yv4phBMnuOxMGz+aEJrh5h3Z6hWd4c46IRCtKlx9Wt2oD5W0hfHcMseaC0bJ7ohN4xdxBJGD4pP1RrLAwcagx82YZp69W1W0UygXDhtkJzM+wnaBAQVQGZNMdoYvfV10e2QyWnwIB/owS8fEjlmMtzZg== 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=pjFuUAlPCzAG7IidBiDVgOgqiX3tGSJKtdVV0MXdGSE=; b=MPqXelaw6+8M1h6EG3bBWTD+gw59QbIPPWcn0ylVQYRIqDogLy6G8wshjQkp8OgfrgcWd71zfGAuobYd/SVM2skvuh/598AMGDsFUDrAc0FEoU6X4fpECW0nBFaP3O0mgLoixM7/4X3CpAK+LswMgO+SiNH4Vsd5aEfIavpw0pU= Received: from BY5PR10MB4196.namprd10.prod.outlook.com (2603:10b6:a03:20d::23) by DS7PR10MB5974.namprd10.prod.outlook.com (2603:10b6:8:9e::10) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.6544.24; Mon, 3 Jul 2023 18:49:31 +0000 Received: from BY5PR10MB4196.namprd10.prod.outlook.com ([fe80::4a17:13b0:2876:97f2]) by BY5PR10MB4196.namprd10.prod.outlook.com ([fe80::4a17:13b0:2876:97f2%7]) with mapi id 15.20.6544.024; Mon, 3 Jul 2023 18:49:31 +0000 Date: Mon, 3 Jul 2023 11:49:28 -0700 From: Mike Kravetz To: Yin Fengwei Cc: akpm@linux-foundation.org, willy@infradead.org, ackerleytng@google.com, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, oliver.sang@intel.com Subject: Re: [PATCH v2] readahead: Correct the start and size in ondemand_readahead() Message-ID: <20230703184928.GB4378@monkey> References: <20230628044303.1412624-1-fengwei.yin@intel.com> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230628044303.1412624-1-fengwei.yin@intel.com> X-ClientProxiedBy: MW4PR03CA0230.namprd03.prod.outlook.com (2603:10b6:303:b9::25) To BY5PR10MB4196.namprd10.prod.outlook.com (2603:10b6:a03:20d::23) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: BY5PR10MB4196:EE_|DS7PR10MB5974:EE_ X-MS-Office365-Filtering-Correlation-Id: fcc020ce-373b-4c34-fecf-08db7bf63c72 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:BY5PR10MB4196.namprd10.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230028)(7916004)(366004)(39860400002)(346002)(136003)(376002)(396003)(451199021)(4326008)(316002)(66556008)(66946007)(186003)(86362001)(6916009)(9686003)(6506007)(66476007)(6512007)(26005)(1076003)(53546011)(83380400001)(966005)(2906002)(6486002)(38100700002)(6666004)(33656002)(33716001)(5660300002)(44832011)(478600001)(8676002)(8936002)(41300700001);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?5peIN0rTRekTBui02sj3Mtci0rB/ZyBCGnR7+bqXXrU0ioNYXPMB6lThuP8j?= =?us-ascii?Q?vH82NwXqCf4QLKCy/zqeuY5++zGiNieWKQYRv9BcF5HmwFvhJMH1ffGLuNcb?= =?us-ascii?Q?mCKAbtbb987fVMNr+IkoDy4Df/PsvDfi7VqwQTaKDJ/geHenr0cFjgSGeaU4?= =?us-ascii?Q?u8susv9L96jYbkZOTmIaomxauXH9ZZyysI2ons+/cIzJR6ZaFK3tqtDDFcv7?= =?us-ascii?Q?+kAEZevcuAWt/IhX0KPkjJHEIo0PNmJw0Sd4dhFPgos+TGUAUHKSF37dHLsl?= =?us-ascii?Q?K/wcz45j2lOt4zPpqEYbXP7irGVaefyiziQLZjq1EwFmGvWPw8Vgo6xHRdld?= =?us-ascii?Q?5+ao2v3CDj0vor5tRnzRLmzXhQkSFwhhvH5ljhZ+Afd0pyPAN44Tg6zV6qBn?= =?us-ascii?Q?YxSarkvvKxzluSH0uQVeZrGLqPD+Fd6dSxfKqWpQ6lVNEvMgxiHhQtUtYTYQ?= =?us-ascii?Q?X+UNJlHeQW3iKYiTO01JGntLIaaIjNVyHTOnABWgUwYtKw5mDDsx1j6FnnXJ?= =?us-ascii?Q?C1CAv4QO+xrRLxfuTTnZEcrMoXMTnji4EYtEH3KB0ezr16UEShB3LPSHS3+L?= =?us-ascii?Q?fR40lA7S1YEu2QZ+NBJLzaS3mifdJi+ETVX2SMSY2AUF7ehtQNq80VIcyIJO?= =?us-ascii?Q?WxXFsbalT/BdczKEeaa9I4/wySc+GVWR7qaGGA3h3gPljb+PYQ2VPQAbI/hL?= =?us-ascii?Q?lnqsJSUh7JEawjaAerHjpia+JpMaLIb2hHDtpkouNZPW+IU8kgyiWRIxswUp?= =?us-ascii?Q?GLAZLiSinPKha3pkp/SiiL6Ar2zIwYPO01ACsimm0NA9hxlZGw6io6FXMh3T?= =?us-ascii?Q?2QLi4+/X/CU4cJk888r8Q9j2GJI6N/oZxwX4dUmT+dNQ8P9tbAQZBFB1GxQs?= =?us-ascii?Q?6wxNQi5YkvqXJyIZfHAMDSZ3RbV2d0wpt/lu/epC/KhI7pHiz9d+N9siJ5In?= =?us-ascii?Q?otkTzcX/smCL0nu5e0b3M0TUj8NbhSFc079lAV2knx1XIzUN0V8fOKKaJIeB?= =?us-ascii?Q?WSPFrPBbH8sx2uYFBeGrL/FgbKe7it0f6BV+igA9yy2Nd9CoGwVGly7w1mg5?= =?us-ascii?Q?HKuQfANC+w9e8+SflnEkMJX3hkA00v7qEGHKgKWd9qLiCCnjVHH0xTgdvT8n?= =?us-ascii?Q?UwyPLT6y3rqQhiJOPLRdnvIlNmMg5vRprXp7+9cLsgux/cn4z35alDZE4eEq?= =?us-ascii?Q?q2u0hqdp0wEfOGm+F1crCdt/yqUlp5XEt9nVUUJxXk0rjVfBIhhbeNYk0KNu?= =?us-ascii?Q?TLgbgaCHVnDQQ9I2WvKAl+Ljh7PGqLl73Up23EwC/7lMs7G9/Vrl2r4kn6Yl?= =?us-ascii?Q?gLHlqgsSjYNZ1OLvOVgUtDWG44Cij0C+zcBE1jeMgCV+d3tspzOOy+os9P3c?= =?us-ascii?Q?ba6wG8/ggccxs59ilSlEz3JlMQu/c4rvpjkkEkAvVTiwGqfa/oBfHStRzFS5?= =?us-ascii?Q?77M355RxCfZM7oj9SeyHl0m96fzou7wRqWDWSi2pxjxOuwVmDRVTuga1MQR6?= =?us-ascii?Q?weYse1U4pp1gzcm/yzn6FIltU4EFVDvKAvF9ZshKDg2c7HO+EnY72jsT5UOs?= =?us-ascii?Q?VDd0Qezzvp4mweJb2OuAETdcTaeciKDk2fqVV9TE2Uc9BJ8irOUNDHLqBGBP?= =?us-ascii?Q?wA=3D=3D?= X-MS-Exchange-AntiSpam-ExternalHop-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-ExternalHop-MessageData-0: =?us-ascii?Q?OmqikRl0A9+i8yo4kLfpn52AD2KxMw0LHX2c3dc07gxw3F1lgHPQnF6VSqPg?= =?us-ascii?Q?JsnYT+NlfSp+Mfmb5Ohpq0yaGLRPpdTujeinH9ESc7PvnjftWsEfoKvj7mVu?= =?us-ascii?Q?4bzUO/Y8DH/klCmnECx+qal9DrSNCUDKUr1rsZn4cwRXEEL66qEqCazQQ8Ra?= =?us-ascii?Q?vfyFh5swn8W/K9u0a0m5EyWZq4QEBFA/Zin1oLdBGN8/WKkVVRUkok2tKCYH?= =?us-ascii?Q?dk85mqXDYzwAlVodPxrxlksv1L+nGKC+Flg9iiDF39dg+zbCNP6j3KtpafId?= =?us-ascii?Q?kELMp16cHukb7MdYCC9oQ4OMgS5/MfBCxRfBzbZ2zD+BsMMYcJReQzsIvYwr?= =?us-ascii?Q?EeSAaHar55DQIuxeW1PUnlBZgWcVS2kY9cu8RlKzX0Emkb2IrMLN10j5sGf/?= =?us-ascii?Q?IOVmWw7WwKB8S6ObMuX/vGEKT/KPgkQkNlZBAImz1WYaO8aqrFErct3prLAZ?= =?us-ascii?Q?eYwdhnOIrDw4hqMmfbooS8dq994SkKxahskFer7UbnESkP7bccLS5U7v0GaD?= =?us-ascii?Q?xjUdZuDE8LecW2fVHL9WyVpJILCdSseeraDKwaiYHARapOIyXojb15cxD16H?= =?us-ascii?Q?fs/VmUE2oGgA9ebIxBdMrKS2fpXPmKIDkjJYtrM84yZ00aUUqZZAqdbtCASv?= =?us-ascii?Q?TzPXuncqwuD2yem3EAJKmBOL89eiXv+rxxrwaRohD+zOakqyf17grwkhTpQS?= =?us-ascii?Q?xbN98nXd0eNEzoxF4DRFyMWHoXJTyRsdaOLgABO6YsypTBallvqBoiu8yQBo?= =?us-ascii?Q?CPTIc+2J+yscNfyGYewpZdFSYisndoogkE7T8hXF8LZn12v3WifRfeXLmYoP?= =?us-ascii?Q?VGbL3zn3MCCDllBU5rrQLesFDaXn2cgcBydxab0mJNiqYijrsTV/UJ0yYlDM?= =?us-ascii?Q?04l8rLHruYvox9JZAn7CgP4/HhVtninop9cvvFa5dClGFe3B+uBBj+ARMmu4?= X-OriginatorOrg: oracle.com X-MS-Exchange-CrossTenant-Network-Message-Id: fcc020ce-373b-4c34-fecf-08db7bf63c72 X-MS-Exchange-CrossTenant-AuthSource: BY5PR10MB4196.namprd10.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 03 Jul 2023 18:49:31.0366 (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: 32rNM/usWk32q+tMqFvwkBx+6Keoly2VLwcwCXeYYNuD6GwUiFlI2fnsRxoy6lCBoM4A9PRUaPkDQd4wBSyZKQ== X-MS-Exchange-Transport-CrossTenantHeadersStamped: DS7PR10MB5974 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.254,Aquarius:18.0.957,Hydra:6.0.591,FMLib:17.11.176.26 definitions=2023-07-03_13,2023-06-30_01,2023-05-22_02 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 adultscore=0 bulkscore=0 suspectscore=0 malwarescore=0 phishscore=0 mlxscore=0 spamscore=0 mlxlogscore=999 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2305260000 definitions=main-2307030171 X-Proofpoint-GUID: EDyNAi7spJWkg5jfcmgDlql1C2osEMaF X-Proofpoint-ORIG-GUID: EDyNAi7spJWkg5jfcmgDlql1C2osEMaF X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: 0CDD5C0024 X-Stat-Signature: qt5zwqajjyzuxhku94exuydbodpy174w X-Rspam-User: X-HE-Tag: 1688410185-466911 X-HE-Meta: U2FsdGVkX18+l9SiKzUes5Qa/CZPI+7K3n0MpKTgDka14rTXS5rnjQ3nDRKWuBJ6s3zIM7z5SS581BH/oWAysCxov51Sh0koRFo0PNErg0KrsYNAtdfb8Fridy8o9RphZ69jjH9EMNcK1eVnhQMfEPwUBlv+bW9Tvwg+zCPOdE53IMwpQHbG9WnXzgYruci6gzhTKN9365qZLLWeKXtAD50ZVd/xz2ocx6utCJPtK8EHHCeRguIF7ep0hLcYFQugoAHwnVQS9jysT17Kd8qWQD/bZS2gOnT6QvdfQMvydT2mFr4RqBYXWSo24xGFM1YTL5dXYOt0cB4hA5IcKcjZlMgpWMmRnC6t8MTPuwkIGix5v/3slFSsdTT+kp5ZYblH6uCQi2k19AVvk3uCXNej4krKrsHqZiwg4B1UMHtfRSQLOWSbkh81RtS5bcRWnV7qNW4Z7l0VZ8trCpogr2O3FHcHsYpS8u/8E9fFsJsJEnQD9WOtEQUYFI7Qc9XPR/pJstgji/CBXl0V8Ej6BUmd2Rn/683I/dodHp/Ic+p9ik087vczh9xFjM5TfUBOdPQxeUe7C9AOupriuthmnAmbnxyi0CSVeq14ay3BXycasaMZLLHt/7rVIWK0uQPvPc6mJD9NajOM7nEHtAaNKE6v66GOzE43WxH7SZMZCujsQiVFgocUnasyZhi2FOBwOaAmpdXlBr1A99kdnYvn5VwuO5bRPbFMqfaCf2RTV2DTFBDKit9kSEIGY8AHgQplr7TayCwm6QF5ftwwMlKs9ap+HoGs3KHKWUt2Xipc6tynJnnCJHn3mE8NSW/Y2KqmJpwkJT8QFQveW8SMCi+t55mw4HkFbEfK9rCg8h3vEeibHxBOyEcosQbIQRuY8XY3O8kZAUu0I445vaHi4YeNoxe7jc0upgvrOYhUP2tW8u3EZDXiiEoVBB+iS9AHsWsjoynE0is+86abgxAOg1wSL13 WuqdjvwQ 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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: On 06/28/23 12:43, Yin Fengwei wrote: > The commit > 9425c591e06a ("page cache: fix page_cache_next/prev_miss off by one") > updated the page_cache_next_miss() to return the index beyond > range. > > But it breaks the start/size of ra in ondemand_readahead() because > the offset by one is accumulated to readahead_index. As a consequence, > not best readahead order is picked. > > Tracing of the order parameter of filemap_alloc_folio() showed: > page order : count distribution > 0 : 892073 | | > 1 : 0 | | > 2 : 65120457 |****************************************| > 3 : 32914005 |******************** | > 4 : 33020991 |******************** | > with 9425c591e06a9. > > With parent commit: > page order : count distribution > 0 : 3417288 |**** | > 1 : 0 | | > 2 : 877012 |* | > 3 : 288 | | > 4 : 5607522 |******* | > 5 : 29974228 |****************************************| > > Fix the issue by removing the offset by one when page_cache_next_miss() > returns no gaps in the range. > > After the fix: > page order : count distribution > 0 : 2598561 |*** | > 1 : 0 | | > 2 : 687739 | | > 3 : 288 | | > 4 : 207210 | | > 5 : 32628260 |****************************************| > Thank you for your detailed analysis! When the regression was initially discovered, I sent a patch to revert commit 9425c591e06a. Andrew has picked up this change. And, Andrew has also picked up this patch. I have not verified yet, but I suspect that this patch is going to cause a regression because it depends on the behavior of page_cache_next_miss in 9425c591e06a which has been reverted. Sorry for the delay in responding as I was traveling. -- Mike Kravetz > Reported-by: kernel test robot > Closes: https://lore.kernel.org/oe-lkp/202306211346.1e9ff03e-oliver.sang@intel.com > Fixes: 9425c591e06a ("page cache: fix page_cache_next/prev_miss off by one") > Signed-off-by: Yin Fengwei > --- > Changes from v1: > - only removing offset by one when there is no gaps found by > page_cache_next_miss() > - Update commit message to include the histogram of page order > after fix > > mm/readahead.c | 10 +++++++++- > 1 file changed, 9 insertions(+), 1 deletion(-) > > diff --git a/mm/readahead.c b/mm/readahead.c > index 47afbca1d122..a93af773686f 100644 > --- a/mm/readahead.c > +++ b/mm/readahead.c > @@ -614,9 +614,17 @@ static void ondemand_readahead(struct readahead_control *ractl, > max_pages); > rcu_read_unlock(); > > - if (!start || start - index > max_pages) > + if (!start || start - index - 1 > max_pages) > return; > > + /* > + * If no gaps in the range, page_cache_next_miss() returns > + * index beyond range. Adjust it back to make sure > + * ractl->_index is updated correctly later. > + */ > + if ((start - index - 1) == max_pages) > + start--; > + > ra->start = start; > ra->size = start - index; /* old async_size */ > ra->size += req_size; > -- > 2.39.2 >