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 B2A35C3ABDD for ; Tue, 20 May 2025 13:45:59 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 2DB526B008C; Tue, 20 May 2025 09:45:59 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 2B2E36B0092; Tue, 20 May 2025 09:45:59 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 17A976B0093; Tue, 20 May 2025 09:45:59 -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 E584E6B008C for ; Tue, 20 May 2025 09:45:58 -0400 (EDT) Received: from smtpin24.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 911231CBBE5 for ; Tue, 20 May 2025 13:45:58 +0000 (UTC) X-FDA: 83463409596.24.CD64B19 Received: from mx0b-00069f02.pphosted.com (mx0b-00069f02.pphosted.com [205.220.177.32]) by imf29.hostedemail.com (Postfix) with ESMTP id 256B1120004 for ; Tue, 20 May 2025 13:45:54 +0000 (UTC) Authentication-Results: imf29.hostedemail.com; dkim=pass header.d=oracle.com header.s=corp-2025-04-25 header.b=FONd2rMO; dkim=pass header.d=oracle.onmicrosoft.com header.s=selector2-oracle-onmicrosoft-com header.b=pGNbFjhi; dmarc=pass (policy=reject) header.from=oracle.com; arc=pass ("microsoft.com:s=arcselector10001:i=1"); spf=pass (imf29.hostedemail.com: domain of lorenzo.stoakes@oracle.com designates 205.220.177.32 as permitted sender) smtp.mailfrom=lorenzo.stoakes@oracle.com ARC-Seal: i=2; s=arc-20220608; d=hostedemail.com; t=1747748755; a=rsa-sha256; cv=pass; b=k+jeLcJ+9YWVHPKz5z9A3hopFBI/grQjC8SQXgtz+J0X1ZkkobBNqHy/XSpJWqNp28KNj/ 4T7WFCtaDtZuBHXRlM13QtgQfbsPgtcO24zCDC5FAHTvTyGujDORd29D0+tScxwviKr2IB KaL7kvpsoe+65Gah69ozxnSU2dPYFgo= ARC-Authentication-Results: i=2; imf29.hostedemail.com; dkim=pass header.d=oracle.com header.s=corp-2025-04-25 header.b=FONd2rMO; dkim=pass header.d=oracle.onmicrosoft.com header.s=selector2-oracle-onmicrosoft-com header.b=pGNbFjhi; dmarc=pass (policy=reject) header.from=oracle.com; arc=pass ("microsoft.com:s=arcselector10001:i=1"); spf=pass (imf29.hostedemail.com: domain of lorenzo.stoakes@oracle.com designates 205.220.177.32 as permitted sender) smtp.mailfrom=lorenzo.stoakes@oracle.com ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1747748755; 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=C/Ww0jtvaHldDDxe1FyUZ5iRqKvSnWNNP4zwp/UEU+Y=; b=vkIXi7ShNEaPaC77+LSRUCJh3btSZCXvECJFblLcV3/1jhDOHTrPcS6P+8uMpUqWh7eHtv OKH24MNYuYqAFyUT5TNJ3H5V1kuflCfdQ9rafq7MnEHmsMDo+BMAB06+bfrAXuicC9t2+7 maqeNcVcX1KIeGO6pOuEx3/ecQIJxWo= Received: from pps.filterd (m0246631.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 54KDc2xE025697; Tue, 20 May 2025 13:45:27 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=cc :content-transfer-encoding:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to; s= corp-2025-04-25; bh=C/Ww0jtvaHldDDxe1FyUZ5iRqKvSnWNNP4zwp/UEU+Y=; b= FONd2rMOdZb9bd/naGLnRMGucLhhffcEcAsl9ZPi4N4kW3ySoWP0M1jecQofD3YN iH2+ddtkVMSOce28/9aszXRprfryWmiTbgq9BAaCN3PKAo0kNLpun27E2Js9nhTe 2/SPKWfLBYol61YfNPhpkY7yZd9cI8YczWh0OjTHXlgpIlwMV+ytqmT41zjNIPTP v8SuAM7blcqMdKmRaQIrlEKwPC1OmRKrDCcqnZ+vaj6WsqOVJZcJ4VQJ+66dcosw jR7Ea1/uoD7mhg5XjtkA/Ed8p83p3ex1ORmrkE8sIunZYbugNx3Ie1hXYGER43E3 7jZGXYukjfr2Ek8TgjOx4g== Received: from phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com (phxpaimrmta01.appoci.oracle.com [138.1.114.2]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 46rtsbr0kp-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 20 May 2025 13:45:26 +0000 (GMT) Received: from pps.filterd (phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com [127.0.0.1]) by phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com (8.18.1.2/8.18.1.2) with ESMTP id 54KCo2na015790; Tue, 20 May 2025 13:45:26 GMT Received: from bn1pr04cu002.outbound.protection.outlook.com (mail-eastus2azlp17010021.outbound.protection.outlook.com [40.93.12.21]) by phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com (PPS) with ESMTPS id 46pgw7se6j-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 20 May 2025 13:45:25 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=PWwA7sAl+buCEJXWFyMdoZ3yw3fI3J5NoEwcfKDfQ1Kn1ZQwbfzQUsPv9mToM0VlTpdkjU1v2m6vlF34r+wxbLsOb0NDYjtASVMLb/Ggm5jzg66MWvsvkpwEH6UmBiTyQCUb9lDsPexXaZi25hlPJZtgaRoKLACwoA3e/RbZoDcGaDVd+a3jtGzM4drRBqxx0wpDlLUIiGt9gecC9mpXQ1xiJyPIGyzJsXiFDhuVPMC26KChOjhvUQAVFvEIGMdjVvIehT1FlWC+TMm25E867hdmmjr+woVSEiQWHIOUIkYr6wlGcbD2Tels1DkUb2JO+zdEgjeN8mCN+7GylN35KA== 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=C/Ww0jtvaHldDDxe1FyUZ5iRqKvSnWNNP4zwp/UEU+Y=; b=OAe/pNan8hkiBK84ohFIVrqTRayofbiG1+3QSIQ9vLRSR6YN4fMoEVdc8p4albVq0SbxKMP3m4ufHfBOOz7ISfLOwQQ2L7aSjCdVFOvyl5EZXU6u0ogaxkcWd7efMJ+1wnUD0gcufqm/Vo2T5Q4BbNKl+uAhlP7xPnyfURFcyzGfClfihbwq3zlBd3GqX1NM6IWd3tI6VEE2ZkBrkof61mumTSTrNji3G2vYyNm0SDYvgu6xvmR5bCE66Dayx2LB220emM0dFyeCANhik5Am8a/1hEjBl4sDC/vs8xPzCZLKyCtrNoWL/XpfS3Rg7w+HDr5PuJRKq7vmTLu07HBpLA== 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=C/Ww0jtvaHldDDxe1FyUZ5iRqKvSnWNNP4zwp/UEU+Y=; b=pGNbFjhi+L5R7XoGHWPZaf5KfCORNLdFR3zBW6YfhIG81gPIT/uhbpRf2IwYeYM+/dzcG+NY/lQwdnU8uDTEGvAzyNvEJo5HujIkohqo06qiUSyCpYdpPQWijhYjH+wGpQiV0HxWdLfucYpOMhRM7FwueYAL3YOgYjoRGxgKsuM= Received: from DM4PR10MB8218.namprd10.prod.outlook.com (2603:10b6:8:1cc::16) by CH3PR10MB7162.namprd10.prod.outlook.com (2603:10b6:610:122::19) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.8746.31; Tue, 20 May 2025 13:45:23 +0000 Received: from DM4PR10MB8218.namprd10.prod.outlook.com ([fe80::2650:55cf:2816:5f2]) by DM4PR10MB8218.namprd10.prod.outlook.com ([fe80::2650:55cf:2816:5f2%5]) with mapi id 15.20.8746.030; Tue, 20 May 2025 13:45:23 +0000 Date: Tue, 20 May 2025 14:45:20 +0100 From: Lorenzo Stoakes To: Yafang Shao Cc: David Hildenbrand , akpm@linux-foundation.org, ziy@nvidia.com, baolin.wang@linux.alibaba.com, Liam.Howlett@oracle.com, npache@redhat.com, ryan.roberts@arm.com, dev.jain@arm.com, hannes@cmpxchg.org, usamaarif642@gmail.com, gutierrez.asier@huawei-partners.com, willy@infradead.org, ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, bpf@vger.kernel.org, linux-mm@kvack.org Subject: Re: [RFC PATCH v2 0/5] mm, bpf: BPF based THP adjustment Message-ID: <849decad-ab38-4a1a-8532-f518a108d8c6@lucifer.local> References: <20250520060504.20251-1-laoar.shao@gmail.com> <746e8123-2332-41c8-851b-787cb8c144a1@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-ClientProxiedBy: LO4P123CA0267.GBRP123.PROD.OUTLOOK.COM (2603:10a6:600:194::20) To DM4PR10MB8218.namprd10.prod.outlook.com (2603:10b6:8:1cc::16) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: DM4PR10MB8218:EE_|CH3PR10MB7162:EE_ X-MS-Office365-Filtering-Correlation-Id: 416d010b-ea08-490b-b77f-08dd97a49195 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|7416014|376014|366016|1800799024; X-Microsoft-Antispam-Message-Info: =?utf-8?B?RkloekQzRDdLWDNwVFdQajRid3RvaGp2bzY4b093UFdQb3h2Q2piamxtckVZ?= =?utf-8?B?RERZTVdOblc1d2JOSXRMLzJ1R3ptT09qeWlZQzd6L2tUQzVOSGI1YlNSeTk4?= =?utf-8?B?RGxOZ2RUZmJ3ckdqU3B6VEx0MmFrWktadXc5akt5YmpaUVpsNFhtM0RmdlJr?= =?utf-8?B?UUZyRzlwNGpiRnRhYmk5VTIvd1g2R0Zmb200c3pWcnh2NnNZYnp5aHAzMXZN?= =?utf-8?B?L1lqS1dubmdqQ1dPV0ZkOXJIbGJBd2NiUWNtbnVyc1ErZURqYWdkK2Rrc1ls?= =?utf-8?B?SjdIcXQ2cG5Fckxub2x1Qy90QkM2aW9Dbmh6R01vZ0hWQ2JaSGhxeDVYZzRD?= =?utf-8?B?T2J0Uit5Q1dsbXFLRnpUMHZnbGtuU2NEOEZGWkVicUhSUk9GRko3dG9kbUFI?= =?utf-8?B?WmxtaEFaTnRuNGVwck1QRnpkZlM5NVpNNDJmV0xQWnp2UCtuNnFRaVRKcmFL?= =?utf-8?B?VnVnRDB4Vk9NVmhhVEx0M2VpeHlvZjNOTTduNWYvTTJNbldFR1pHL1dmaW56?= =?utf-8?B?dUtod2pnRnpYRXJFV3FBaDE4NjZ6ZW9CSGE2SzgxMllaekxkdTN4S1d0azhF?= =?utf-8?B?WSt5Slc1QzBpdDNXc3RoSnQ5dGw2NjkxR2VXOXF3elhZTmVxMmprcUdLNTVl?= =?utf-8?B?UjlDVVIrSUFBME1ueW00a1BVd2syMkx2TnhjZHpCeXNyQWZIeWFVTWJpcG1S?= =?utf-8?B?R3VrREQ1NEVpYis4NDNyNzJibXVxRnFqdWN6bHB3ZUgrZkEwblBhWjZ2S0M3?= =?utf-8?B?WTVyOVpEYjFBVGhXWTZwdUMzMWhORWMxLzFQWFZJckU4bUdZWGdmTExaN1Yy?= =?utf-8?B?UStNUHE2SmVyeTBWMUo4cmFSUEpDcWdCQURuYk1tSjM4MUp6dlJNai9NVzlK?= =?utf-8?B?Yjl1TW00MGlsT0VkWDJFWk83Rzlvb1FOemt3VFpxaFpzdFVBOTVWTlRXRkZU?= =?utf-8?B?ZlZiNGZwSVI5Z2c2UjU1UXAyc2s3VGtOT2xWM1VYTzVLU2lWeWpWS01ZTzhX?= =?utf-8?B?QVc0QzJrSmQ0aXJXYlVVdlRzeGJ3Wm9LK1ROdlVpcFJ4N2x1M3NBelUzZUt2?= =?utf-8?B?REZjb3pTclJ1TlVnOTh5ZHhSbFNlakNNWWs0WVhpK1pEOW5Gdk1kM2NtZjFz?= =?utf-8?B?bDlRSy9yMzlzaEJ3Z0dGK3ZmWExlY2NGUnZEL2FPNHU2TisyNzRsOHI1aVVk?= =?utf-8?B?eHF5b2ROMUUzWVZtRnU5MEU0bStrcHNUazJYUUgxOEM5QjROdmducGsvSit2?= =?utf-8?B?ODVnL0JINm92ZTl2ckFoZnZtWmdNK05FUEpOZWR2MkR2NTdhRi9qRXlHRlZv?= =?utf-8?B?V3NTSWZWWWp1Y1V6L0wrZHVoN09YRHRON2JGRkVjblhvdUNPMnpWNDBBbmY0?= =?utf-8?B?VzlPbW05TjRpNXY0UU9EYUp0RjU2VHV6M0pzbnNpSkZkTC9ZR0ZVdTlNcTZX?= =?utf-8?B?R0VxMWNpMXZKK2NMYkpmL0hrTm5jZG5FUmZBZXF6Mnh2TXdOTUlXNlVidlBQ?= =?utf-8?B?MFpLNytVTEwzc1Z4ZVpRRndua1pIVDI3YnlpcTFXNGhpZTJRT3BhdGR3amgv?= =?utf-8?B?MGN3czdnbGxlaFh6OWE2RXN6R0JLdjlCM0FmaGJHL2xtby9tN1hhNGlQcUtX?= =?utf-8?B?QnFlaHFVWjVxT29qRUJnYS9QY0ZkK0sxaWdzMW9BWndPZndySnJpMFJLSlhN?= =?utf-8?B?YTJVNXd2RElOSWpFbWgrdEJaUVVhUjFWQzZuN1U3WmdkTEZodFBJTDhneGlt?= =?utf-8?B?bHUzTzZhcGhMSTBuRXFoR3lxSTZhakh6MkxmMGFOQStvWXB5cFAwaE8zek9t?= =?utf-8?B?VlBMeGhYY3VGa3hZU0N6TDYzT0FtdDRnUmRGUjlQT0ZKRFdNb3dYaDZYRENV?= =?utf-8?B?VDFnc3Z2N0VrR0R1NG5Kc0lUT0xsamFJSStCQURUYnpTZll0UnRsbG9ubk9V?= =?utf-8?Q?v1ne7tS+UF4=3D?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:DM4PR10MB8218.namprd10.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(7416014)(376014)(366016)(1800799024);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?Z1c2TmhsRUM3T2VNemc5c0FDTFBqVTU2SDMzVkxtcWxTKytJMEhNeERWeWla?= =?utf-8?B?TC9odU1rS3NoWHBWUTRDVEZHbnRldmZRUnNLeGcyM0hTdHErYVU3dFBjM25j?= =?utf-8?B?TzMrSytIdkIrTmYyY2M4ZFVBTFVvWUY0dS9nVW1pTUJMd0pUYkR3VFk5N09C?= =?utf-8?B?ck5iNEhQemMxMitGSmNGcnFmK3hlTXp5TVpHVG81Szh1ekgwOWt1Rk9YT0Nm?= =?utf-8?B?TU0xS3ZqS3pKdHFxd1RVa093T0ZVbkJGWjdVQ3ZPazdraFdGV0FOeGpidDJp?= =?utf-8?B?c3J0cjNPeE5FRExCQ090RmYwY1M2aTJHN1lmWXc1aUI0WElmY0syTEMyZ3U0?= =?utf-8?B?NWtmalNhS2VhNU1VY1NpWTdzVzNzWnhJVk4rb3ZlaGsxY0EwTE1uMTZFU0lT?= =?utf-8?B?V1A3MzVUczhyWkJKakdJS2RENWVIdkhWbUVnQ09ZVFZiTnUwdTVOWmtnb0d3?= =?utf-8?B?WHJpTjNhdFFWRFcyZ21IYUtMaFhqclJuNmU0eTBidGhJbWdVSXVNUndreEcz?= =?utf-8?B?YzI1dzhyT29iV050eHpmRUY3SjJFQmRtUnBTbUN2WDc1aTlVOCt4c2Q1UjFG?= =?utf-8?B?YzhUTnlXRGVYbkRHaXY5NE54Q2pER3N3SEF1enpCT0g4Q3R6VmJsNWxiYkJw?= =?utf-8?B?WkNoNzIzakU3bWIxMVVBTFNOdDVlaUMxaEVnejc4R1Y2cWZId2UyOHk1ZEo2?= =?utf-8?B?SFhiWHMrZkRPYW1JeXRweUxlb0J3OXFnNE44d2VOK2ZIaGhPTFkzNFNkb05D?= =?utf-8?B?ZjNJdDRMUGJjMGFDaW42WHVOMVY4UzhoMkVLY1prNSsrOEttRGFKQ2pwdHBR?= =?utf-8?B?d2F0VlJTRGYvcGNlOTRabUFGRUdKa0hZckxvWC9VV0UyVm91K0VxOTZEYlI2?= =?utf-8?B?clFPZG5BUklLTW5JK2tmNEdsZXdxenc4VlhpMjVLbG1DeWtZSC9VcmNyVkVR?= =?utf-8?B?a3djcE9tU3VnbnJDaGdsUXhUYUcvM05GTDBZV0lPODlLOWJSKzdTU2dTM1BX?= =?utf-8?B?ZDdSdGpGV2cxeXhwalk3T09EcGF3ZWVMVUluR1QzOWQ2eGdXR1BMWXFqL0pp?= =?utf-8?B?c2ZDZ0NJb0EwL3hMdW9vV3ZNbmhDYm53SW9yODE1WTZVQTIyMHlYSDUzQzNj?= =?utf-8?B?RWZtRW92aGZLYkowTTBqTE9HdlU2RW5kVkVYMnpyaGo3aFhhdllQOTNQNFFP?= =?utf-8?B?U1RYRURXUTYvYzI4eEZUV0xTTjlPRmxYVHdxN29nbW9YdUJNQmFCUnVUL0VR?= =?utf-8?B?OWVzbUxPaUprM1d2Y1JzRHIwNUZhV3ZzZklxWVpTSDJ6UmppTW5IMm44cE56?= =?utf-8?B?ckZ5MitXYUFkWTNQUDdDeFQ0K1pIUHBjcFdQcWFkWEVqWUFaTHBrWmVyYnNF?= =?utf-8?B?cXIyMTl1dmNyTVBRN25YeFBuN3gzS00yQlcvRy9HaEx1QkprOG96Vlk1a0Zn?= =?utf-8?B?ZVBMbHdRcUw5NkFxbHZiTmNsZ21LcGhpQ2xJcmxOTFZTZjBWb0tHL2FyTHkz?= =?utf-8?B?T0Z6Tk1LWjk5ZlBqY1FEMDd6ODA3ZHJVQThLcXEyV0ZSU2taOUd6L2w0ZGRh?= =?utf-8?B?OElOalVBQkZvcWFwc21PWmRPeFJHT2FHZDlEc1A5QVd1WDMvVHBVYVE3UCt3?= =?utf-8?B?QjRCTkZvQjR6Qkp1T1J5WFhOclZEM1A0NnNTSTBEc2ZKSWhlYkM1cnpjNWFN?= =?utf-8?B?Ym50S0RwaWRna1RrVnFWeFZLVHNzQWpnTTJyaEk5TFM1VkM4aDdRbG1XbnBL?= =?utf-8?B?WmMrcTNKNXM0T1FBbzE4anYrUExlV0cwSGpjcVN0OTcwR2UxeHdzSWJJOEo3?= =?utf-8?B?dnBOeWVZcG5CUVU0TkxlcVUzWTY5cWlkSi9rMHBGcjRzRi9yMGh2aFB0MFIx?= =?utf-8?B?T0g4cVFFakhKQzFVaE1XM2swWmp1bUdFUkpmWFNudEsxUHgzQTJRc1N6b01C?= =?utf-8?B?KzdmMld3OVViV3I2QXRlQnJNL2dNeUFXbmdoam5YeWc3VnZiTWFhMlBwNVlC?= =?utf-8?B?djU5TFZCRWZvVW84cEVISTZoalFFQUwwVnpBSkwrd0xXRnRHKzE5ZW5JUzVR?= =?utf-8?B?Q3R1NWlWRExkK3p1Nko0TWxQTzB3S2xqL1lzdTBScDRob215OUNubEFJdS9z?= =?utf-8?B?RStzY3RZYkJhWjBLS1hFZDUwaUtVWnpSclpadXBkN2dOZTYyUml5MHBhei9Q?= =?utf-8?B?MWc9PQ==?= 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: 416d010b-ea08-490b-b77f-08dd97a49195 X-MS-Exchange-CrossTenant-AuthSource: DM4PR10MB8218.namprd10.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 20 May 2025 13:45:23.0165 (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: e0Hq4ImZMjZn0SjsW6Q2e1vTURvZp9QchnAwfLJdRcw3CIM9mDj2+UySHxZ0Yf9NoekGJ9kXsIMMh07MOi4RF6I0zkxWJ+N7UXu+5BCF2Vg= X-MS-Exchange-Transport-CrossTenantHeadersStamped: CH3PR10MB7162 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1099,Hydra:6.0.736,FMLib:17.12.80.40 definitions=2025-05-20_05,2025-05-16_03,2025-03-28_01 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 malwarescore=0 suspectscore=0 bulkscore=0 mlxscore=0 spamscore=0 mlxlogscore=999 adultscore=0 phishscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2505070000 definitions=main-2505200110 X-Authority-Analysis: v=2.4 cv=D5BHKuRj c=1 sm=1 tr=0 ts=682c8776 cx=c_pps a=XiAAW1AwiKB2Y8Wsi+sD2Q==:117 a=XiAAW1AwiKB2Y8Wsi+sD2Q==:17 a=lCpzRmAYbLLaTzLvsPZ7Mbvzbb8=:19 a=wKuvFiaSGQ0qltdbU6+NXLB8nM8=:19 a=Ol13hO9ccFRV9qXi2t6ftBPywas=:19 a=xqWC_Br6kY4A:10 a=IkcTkHD0fZMA:10 a=dt9VzEwgFbYA:10 a=GoEa3M9JfhUA:10 a=yPCof4ZbAAAA:8 a=_cmZ69J9DheNdRwnwkwA:9 a=3ZKOabzyN94A:10 a=QEXdDO2ut3YA:10 X-Proofpoint-ORIG-GUID: 1lJGg6s6yFKJO1SXeeNml8BjfX2TTmn8 X-Proofpoint-Spam-Details-Enc: AW1haW4tMjUwNTIwMDExMCBTYWx0ZWRfX02vCjm1HJm/u n6fGl2XlooRcQb935TW1ABBDvBA2mViZ2HXEgMlLjgKLb6PAEIy1Zp8vaGk+GTB+hffLTmzNN5x fhxfLNfB9+UT9gzkMzmhOUzl/uHOy6eUjd5OBqT08g+KZ4pFNeh8uxF+bsA8lqdrs1pivo/1IOd jKH+TAD21oZOrH8goCLt3BCpwx+nsq5PezWReSuyedLGvJrBDZ3KKcYIlDuOAlchVJS3t+1pGLk qZAfO+jKwT4gcRqZnI3KKycglhNxf+avBCL2RQg4Of/jFPWkRl0L9Z8f6iaLWmKac1xpUaIoVZf 4H2PWBvHkxyAPj+q/KLYeKVZuHoEl3hjL4j5VGOlutB8ibGwTTUPZ3iH78rBVc88Gveb+/8JNU/ hWWGynC1JCDY70IEGxNomc4eT9m+CzMlq5VBc3R03Fw9EBbaphTECF/Q9rsvPaZgBkViUlPl X-Proofpoint-GUID: 1lJGg6s6yFKJO1SXeeNml8BjfX2TTmn8 X-Rspam-User: X-Rspamd-Server: rspam07 X-Rspamd-Queue-Id: 256B1120004 X-Stat-Signature: pfjugfgkhyyfc8gb55j65wa78gm1oz1k X-HE-Tag: 1747748754-138584 X-HE-Meta: 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 yI71txJD 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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 Tue, May 20, 2025 at 08:06:21PM +0800, Yafang Shao wrote: > On Tue, May 20, 2025 at 5:49 PM Lorenzo Stoakes > wrote: > > > > On Tue, May 20, 2025 at 11:43:11AM +0200, David Hildenbrand wrote: > > > > Conclusion > > > > ---------- > > > > > > > > Introducing a new "bpf" mode for BPF-based per-task THP adjustments is the > > > > most effective solution for our requirements. This approach represents a > > > > small but meaningful step toward making THP truly usable—and manageable—in > > > > production environments. > > > A new "bpf" mode sounds way too special. > > > > > > We currently have: > > > > > > never -> never > > > madvise -> MADV_HUGEPAGE, except PR_SET_THP_DISABLE > > > always -> always, except PR_SET_THP_DISABLE and MADV_NOHUGEPAGE > > > > > > Whatever new mode we add, it should honor PR_SET_THP_DISABLE + > > > MADV_NOHUGEPAGE. > > > > > > So, if we want another way to enable things, it would live between "never" > > > and "madvise". > > > > > > I'm wondering how we could make that generic: likely we want this new > > > mechanism to *not* be triggerable by the process itself (madvise). > > > > > > I am not convinced bpf is the answer here ... > > > > Agreed. > > > > I am also very concerned with us inserting BPF bits here - are we not then > > ensuring that we cannot in any way move towards a future where we > > 'automagically' determine what to do? > > > > I don't know what is claimed about BPF, but it strikes me that we're > > establishing a permanent uABI (uAPI?) if we do that and essentially > > promising that THP will continue to operate in a fashion similar to how it > > does now. > > > > While BPF is a wonderful technology, I thik we have to be very very careful > > about inserting it in places that consist of -implementation details- that > > we in mm already are planning to move away from. > > > > It's one thing adding BPF in the oomk (simple interface, unlikely to > > change, doesn't really constrain us) or the scheduler (again the hooks are > > by nature reasonably stable), it's quite another sticking it in the heart > > of a part of mm that is undergoing _constant_ change, partly as evidenced > > by the sheer number of series related to THP that are currently on-list. > > > > So while BPF may be the best solution for your needs _right now_, we need > > be concerned with how things affect the kernel in the future. > > > > I think we really do have to tread very carefully here. > > I totally agree with you that the key point here is how to define the > API. As I replied to David, I believe we have two fundamental > principles to adjust the THP policies: > 1. Selective Benefit: Some tasks benefit from THP, while others do not. > 2. Conditional Safety: THP allocation is safe under certain conditions > but not others. > > Therefore, I believe we can define these APIs based on the established > principles - everything else constitutes implementation details, even > if core MM internals need to change. But if we're looking to make the concept of THP go away, we really need to go further than this. The second we have 'bpf program that figures out whether THP should be used' we are permanently tied to the idea of THP on/off being a thing. I mean any future stuff that makes THP more automagic will probably involve having new modes for the legacy THP /sys/kernel/mm/transparent_hugepage/enabled and /sys/kernel/mm/transparent_hugepage/hugepages-xxkB/enabled But if people are super reliant on this stuff it's potentially really limiting. I think you said in another post here that you were toying with the notion of exposing somehow the madvise() interface and having that be the 'stable API' of sorts? That definitely sounds more sensible than something that very explicitly interacts with THP. Of course we have Usama's series and my proposed series for extending process_madvise() along those lines also. > > -- > Regards > Yafang