From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx0b-00069f02.pphosted.com (mx0b-00069f02.pphosted.com [205.220.177.32]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2AE99207A0B for ; Mon, 9 Jun 2025 15:09:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=205.220.177.32 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749481764; cv=fail; b=lwNrlihN2xyW7ZRdD8F422EuqvzZJ8YvjDu3dvNN7yZ0Hcpo/u4uVyZ9rbFNuRmaZLUGSTRKNyc6rBRTOEjTCDuyT+e3PSNIRql3G+BmcGW3LJsiJE/bG184FPF7a+mwxlHQ4vRmZUnA7f0gPO6VlDBD+Nc8e71kHyODAKD43XU= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749481764; c=relaxed/simple; bh=waXfl+m7xwLvNfXSpri9S3Kzq/AYkwhCVPuUEK7dfcM=; h=Date:From:To:Cc:Subject:Message-ID:References:Content-Type: Content-Disposition:In-Reply-To:MIME-Version; b=InQOk1s4fpibq7LiEfpKSqy4tMhVpwR18Wr7cXw99i5Z2YXTco7Vt4SQWZTYlaLxb1PgC08rySMN4j2ND8+kNOOEUSo0TBv71gBlnlMWaCyNs1y1UzUbRpfeujI50a/TlfOZ4N4c+YY6XDTm3D5pJ4j6oEqVHFv/+QNs18qrebA= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=oracle.com; spf=pass smtp.mailfrom=oracle.com; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b=mabeM8yW; dkim=pass (1024-bit key) header.d=oracle.onmicrosoft.com header.i=@oracle.onmicrosoft.com header.b=frzO74+A; arc=fail smtp.client-ip=205.220.177.32 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=oracle.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=oracle.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="mabeM8yW"; dkim=pass (1024-bit key) header.d=oracle.onmicrosoft.com header.i=@oracle.onmicrosoft.com header.b="frzO74+A" 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 5593ilXl017209; Mon, 9 Jun 2025 15:09:00 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=cc :content-type:date:from:in-reply-to:message-id:mime-version :references:subject:to; s=corp-2025-04-25; bh=waXfl+m7xwLvNfXSpr i9S3Kzq/AYkwhCVPuUEK7dfcM=; b=mabeM8yWDmm3hoGi5WonFFGyK8N7ja3hIX H+TrsjxjpHZBGobmzMt2zcHbuMrLGDIwboYuuUfuEjfa+6pdeQiucIOME4YRDQ89 Fx0ZCHPjVYifAy3CnhiRpHw7cwNUjIjC1/19CB976z34gEtr0+ll4VmhAum7nd7j Dhmx1kOrNJcpCco7i1eULwzRptNzh8J3waSuFqUxfzuglrTPl2nO1Cm/8DUa3l3E erW6y+aPRr3wHn8t9sOoqpJiUnZVsZRM3wEILVYHZhw0aH7t+9tHIX2P28Ptu5Im jh34czRiaCUi2bes/G9zZqYCtvwg4k9/dAMd5UqTPIUVSoTIDW+A== Received: from phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com (phxpaimrmta01.appoci.oracle.com [138.1.114.2]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 474c74tc8a-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 09 Jun 2025 15:09:00 +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 559E067o007379; Mon, 9 Jun 2025 15:08:59 GMT Received: from nam12-mw2-obe.outbound.protection.outlook.com (mail-mw2nam12on2040.outbound.protection.outlook.com [40.107.244.40]) by phxpaimrmta01.imrmtpd1.prodappphxaev1.oraclevcn.com (PPS) with ESMTPS id 474bv7aepb-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 09 Jun 2025 15:08:59 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=nMLm18oCqmHFQB3F6ZXQx2aX0CBHWz2TMJA9GPYUCJ+FV/Qn6y83IZRHMR1dyxrD58wF/jFzgy7GOaxVu2pp+h4/zhIhlS/pgQWTWhZgrC2jKVmN9wc1uxijisQPbxQcDTe7LYbibFqbnAcufhMTCBdNTngG3HJRlnr23gnIlulF8eKoPstrrI1eIus8tqbIYRTB/9Ct2nJqot7zPYedvLFeRopIpn5Jw3dvTGuO+1uIz2ZIYA8o0U4MuHLLgCcqSaOxpDnjRhGdFBk4TCbIeha7qaR8TzhF5yzPQ2VN3I5JuSs7/yB1dUIIaqtkt7XY0hbAlWAwA995tHxRc+d89A== 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=waXfl+m7xwLvNfXSpri9S3Kzq/AYkwhCVPuUEK7dfcM=; b=QpIFvpWlp2J6OPQSNPQ8DjWGfaI0AODMEm+Rt/Y7Trg5EllIunVpjh87jTqofFA/5YC6Vaet2Wpj6nbycSiLKyKKa3dutI88xbIM/aTo+kkBCLkF2NhdMaUdH8VKxT8ULAjz6EHGTIjkQX0Y3J8uQDGIIZgpTQf3+Y9CfwN4nNzzQFI4/P47Tusawx5pZaA10JHKWvdRx5ZRnpm9ObFwguzdUT1x+MkSIFYPLCvAE9LcsNue0B6GA3uxrH1y57X3TPUblsXBgH/6TxHqwdnIGcEbf2Zur0a7ip3wmAFtWQu8THdlpLKKzkM4JtMSlvFcvwB8zwFFrk951+4d0uAv/g== 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=waXfl+m7xwLvNfXSpri9S3Kzq/AYkwhCVPuUEK7dfcM=; b=frzO74+A3RDWCam58pQU4pbB2vcOAmu5oYEeGFHrA9ImuD/Yn7qOtWAIqbW1YNqr2MJ14Ztc1PRne/jAZ2k3iI5watitClCHk6n6Jjs+YycVsdvaSJuMmDpuDrGwXfJQaS2WMdPOFDXvEd9tkjRya6bMH06mWRjuEH/l0PhaRBY= Received: from BL4PR10MB8229.namprd10.prod.outlook.com (2603:10b6:208:4e6::14) by DS7PR10MB5008.namprd10.prod.outlook.com (2603:10b6:5:3b1::19) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.8813.24; Mon, 9 Jun 2025 15:08:56 +0000 Received: from BL4PR10MB8229.namprd10.prod.outlook.com ([fe80::552b:16d2:af:c582]) by BL4PR10MB8229.namprd10.prod.outlook.com ([fe80::552b:16d2:af:c582%4]) with mapi id 15.20.8813.024; Mon, 9 Jun 2025 15:08:56 +0000 Date: Mon, 9 Jun 2025 16:08:55 +0100 From: Lorenzo Stoakes To: Qi Zheng Cc: Jann Horn , Barry Song <21cnbao@gmail.com>, akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Barry Song , "Liam R. Howlett" , David Hildenbrand , Vlastimil Babka , Suren Baghdasaryan , Lokesh Gidra , Tangquan Zheng Subject: Re: [PATCH RFC v2] mm: use per_vma lock for MADV_DONTNEED Message-ID: <5afabf30-da5f-4fa8-b1c2-e3b384c2d99c@lucifer.local> References: <0fb74598-1fee-428e-987b-c52276bfb975@bytedance.com> <3cb53060-9769-43f4-996d-355189df107d@bytedance.com> <7cb990bf-57d4-4fc9-b44c-f30175c0fb7a@bytedance.com> <5fac6f20-2643-4d98-a29a-06471f156762@bytedance.com> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5fac6f20-2643-4d98-a29a-06471f156762@bytedance.com> X-ClientProxiedBy: LO4P265CA0044.GBRP265.PROD.OUTLOOK.COM (2603:10a6:600:2ac::23) To BL4PR10MB8229.namprd10.prod.outlook.com (2603:10b6:208:4e6::14) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: BL4PR10MB8229:EE_|DS7PR10MB5008:EE_ X-MS-Office365-Filtering-Correlation-Id: 9d151535-f575-4006-27d5-08dda7678e3d X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|7416014|376014|1800799024|366016; X-Microsoft-Antispam-Message-Info: =?us-ascii?Q?Ec2Yken35Dv1leJLm07s6sFAiVDYXMcDLyZFWTqGdw2E/DCwCzzuYk0e4rmw?= =?us-ascii?Q?7P8elmTLzQPhTWXgmn8zzlBt8FxBHYxm0zRyBEkmSWWITwSrSzL8ql5UbRQK?= =?us-ascii?Q?NdnhmMDdJ1YLa0/IJmNxqvB/ywu16awrM0k6OTyEWLTt3d/z0ZvG+IXR1AAV?= =?us-ascii?Q?YmButI95gKkxgYawpNDNNpzGGg+tKQv4WZWu4rQJM3JfPKZsrU/CSrhw/CWS?= =?us-ascii?Q?kvFt8ytXmDZWTh3l5t2KYKDuYv62krXVZAjF0YE/CP8SrJI+DDzsxMZGARvp?= =?us-ascii?Q?Te/HsLmYf9NImkyelryfNpLBMm1HOwnZxNQ4HAhPqkcQtFjQG4JJD4pcN9QU?= =?us-ascii?Q?udrUcKbJEwZwXktuQ58heeJW1wbNcFF3K3AAwwMjA3q1VKH+bhD63RYpbbmd?= =?us-ascii?Q?/EeGk+aZ7W6N2a2c80eW8KygZnG5JoxFmJvT6jH/aSVMovxQplUFqaED+d+j?= =?us-ascii?Q?XYqu+NvLEQOsHuivXTkubSHMDe1Jgs1/enE/afKwcRr8l3nK3aVs0q5NxfeC?= =?us-ascii?Q?car7snfdsBH3AMuQRkMyXYDcvAL+JHaRdRcOS0aPruozExpAiix8HE5W7b5B?= =?us-ascii?Q?APnn0mGMc1clMRmaDf8kt4OTb4TdaMeKc7k7TzrKqSKL8npT9S83zVnihfel?= =?us-ascii?Q?7n8YcqOPa1wlA/8nA0unPudkQ+k9MYR8WKqcrwv7sPjwlwPAtbtM7agU0x6k?= =?us-ascii?Q?vL2ly8HTrHnrz6Ue1DwhrAQ7ZgffGQTYADY2XKGpU8w3IeBgbrSJzzwzlQRf?= =?us-ascii?Q?BaOOz6ZyRHYz9nFUtgb75AZUpnFEqXjc3dtBx5zny3UlrUiZiUW06k6IfDQ1?= =?us-ascii?Q?vS+oLBvUtGkYaXYXAyUtzCDoUg3oVsu9yVb3wcfZ5qBewCuc26ebn7LpVfKx?= =?us-ascii?Q?/Ta35wpiTWtgmyZ1bhWfCff8NgTs75Z+v9LDddyrRdiY67MfJE8pOPHjWFbm?= =?us-ascii?Q?CCgheY1icuv7u2eCesiZ6zCRjKRasH1zU0272hJHETy2aWXldh/311VLTk+Z?= =?us-ascii?Q?BaH564Yjzhgewgca9WOp8LpYjopFfK6IFCP7S5eUafZKBvmOKWU2w6xwMg7E?= =?us-ascii?Q?cSmR0VnHCcJ8FSbL6Tf4yvnlZcDTRapU8+HyirSewmifC+a2/ZUzEtSR66C/?= =?us-ascii?Q?kgJKxCM4fw5hefh1IECzDetYRy3NpNEBs42Hu3dvxcZWnOadrBWkJqFJIa5D?= =?us-ascii?Q?YvmBFZ87Ecq6tdTcDbFpdz0pbbLuyWKVFor3fL0ocE/WYI3vN6tnYKt8XYrA?= =?us-ascii?Q?iDl11cjodc9WLrwWZhi4c4rBe675K33A0wdg2ldZrpq0wt49p+47b47pttGf?= =?us-ascii?Q?tWhFxHogO0MYkLtI2/4zDSlEbkzJamFSKck5cnEyYkw8Vel851Mpdpolj/YS?= =?us-ascii?Q?S8u3FiTbFXlGa3RRMgscHQFpu7JKvx6W5FArnzySGwdZIuaNT6uGRdxGXCZv?= =?us-ascii?Q?C/wvw4efA1o=3D?= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:BL4PR10MB8229.namprd10.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(7416014)(376014)(1800799024)(366016);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?YuA9P9GxP+E7MCGK0Q/nZv7vSnsN5wwVwv4LQuiKw0fmRWtN1EWhCmsqWUR8?= =?us-ascii?Q?OZ6j4ZnjIUrg/H4kjx3tOE0j3a/4B/ioATFwOU1oGXfGTWhwDFMmxAIC/D7t?= =?us-ascii?Q?4tAGa/3L3NdFRpI+ngU5mf+DJ7l/6ipFtj/brU8CV2bTj6s+5Dg7NUK/0uYQ?= =?us-ascii?Q?awVfwSo0aFwFHeEC9D7Cu0T+kQNq15BLwlCyMsU7SfUIcTEqhxNpi02HcNbu?= =?us-ascii?Q?TXelpDmCPmxPJ0xUOOWR+b7MKa7es46c6jrSBQS3pU9MktDT98AMjS0hG4ry?= =?us-ascii?Q?DPGquswT7mdDHUl8r3BIW4wEvzGh6wIlb311ytfauMVjpa5UzcCy7K3jdR/j?= =?us-ascii?Q?lgKyaUiYz0+9VXvglzsL1zrXC3ok5Im7emT54/d0K5ZGLVyAfw36/N9g3yHz?= =?us-ascii?Q?Zd7AeLFwPl1LAQXYNC2N3X5WZmYVIq8VdG2f+NUTVF48kmw4p0iSi0L1hX56?= =?us-ascii?Q?IqtP5aQQzaw/MaWDN+ALp3UI6vd4tkKYjDbMAsW77j9YQE26x3FFBPY7zVDL?= =?us-ascii?Q?PStDNqJzXaM7x8VWWcgI/ikGb9CkY14A0MdAAD07T3PCx9FEqd36YGjvj6qN?= =?us-ascii?Q?e5UcuDsUEwr6ZFh71RBVy3oJ7irQQH0M/sYg2KVZlQJtdGLLMfJHqLni5XmT?= =?us-ascii?Q?Uj4qomuZ7oetmcgtkr8QWoC5W1d9/WXwjgkovzjSpvIgaMJtlAmSkGUPORIW?= =?us-ascii?Q?ck8Gn4ORBdQmyy53Me4GgxYP8BgXdTTEg5w9woMaJBYLaybwUx6C92yYcxJi?= =?us-ascii?Q?1iauluQuwN+lZ2FxGIWVAn9E3HnxYcgXc/M9J3Da4SVby83A12H3Zr3zsYTo?= =?us-ascii?Q?YPQ7gNfsiTXzLGMpkbirgUqG8sKvapVWhDASe0jma9cZdkER9tuQibWtRhUJ?= =?us-ascii?Q?Rb6+IjQ8/Pn4ERMBNogzm5vuyNdgPptL55tnUSSSN4V/T9JhASE5mcY13UdW?= =?us-ascii?Q?lFd37a2BPPTWoOsrDRwxM3hsBstk/v57BsDcK4bbhyYCPTlAmh8PEKEtYaJi?= =?us-ascii?Q?k72ReUFNWmHJfqNRuRrW+L45IUcfjcf38MrGyL+kh0Ag7zALbxWNczmFknnr?= =?us-ascii?Q?FysO8RWbleQaqLW36c1OFkPCwaPMrUDjMYIcAyg65tdlts0sBVHgpVnPRCtr?= =?us-ascii?Q?7QJ7Mb8KsauZ8nNfKePDX4FHsw53vIMgt1lIpTX0zIic9C7Fvt0zorCICkCW?= =?us-ascii?Q?hV3UwppxJkLI3KYhcwtTTSW+Sj/DD4beSy7pCRd5Hle04Rec9FVRb/Ta29si?= =?us-ascii?Q?vujuPCjSL8tqCPHiFZdBxQgFT6azLM3EPiRWJ/MreuZNN5v8VxohLy5t1OkT?= =?us-ascii?Q?K0CHgEhl8gTS6+jQABDYQ72+N1IsfZSsc7nXqRxLJmlXNq4WD8NPsvDCozxF?= =?us-ascii?Q?PXxA9fsXA/224sFXZuNTiPCrj3SV2vl2PsuunNoh6Ec+euxCktAUjwOSezrl?= =?us-ascii?Q?KRVgOiodSFdiOnfX+KFscZ9Rz6Rbotb3om2LKT5DzwtiPNDyj5QaVgyqfUiR?= =?us-ascii?Q?UEwqbTqHT1HaDj9//lq2/jBAjFC4+A1nbJSA2NXZMNzDqSkQrucHxAcRqrff?= =?us-ascii?Q?gwbL5zUwK3IXd1qeoyrmQmmgkdOruafK1zdfhMiZdM2/F8Hff+F5BSVr735I?= =?us-ascii?Q?Rg=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: 9d151535-f575-4006-27d5-08dda7678e3d X-MS-Exchange-CrossTenant-AuthSource: BL4PR10MB8229.namprd10.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 09 Jun 2025 15:08:56.7401 (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: uKR8bSTCmCnXD/35DkoG9dJx+NmG0h46EP+5k3z3SPMrLLBvuHiadsmuGJr6AWQjPAu8lL6LFbdOXVuFXBa+k/riqxvOfzTa68mnIGjvk9k= X-MS-Exchange-Transport-CrossTenantHeadersStamped: DS7PR10MB5008 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=2025-06-09_05,2025-06-09_01,2025-03-28_01 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 mlxlogscore=634 phishscore=0 malwarescore=0 suspectscore=0 spamscore=0 mlxscore=0 bulkscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2505160000 definitions=main-2506090112 X-Authority-Analysis: v=2.4 cv=LIpmQIW9 c=1 sm=1 tr=0 ts=6846f90c cx=c_pps a=XiAAW1AwiKB2Y8Wsi+sD2Q==:117 a=XiAAW1AwiKB2Y8Wsi+sD2Q==:17 a=6eWqkTHjU83fiwn7nKZWdM+Sl24=:19 a=lCpzRmAYbLLaTzLvsPZ7Mbvzbb8=:19 a=wKuvFiaSGQ0qltdbU6+NXLB8nM8=:19 a=Ol13hO9ccFRV9qXi2t6ftBPywas=:19 a=xqWC_Br6kY4A:10 a=kj9zAlcOel0A:10 a=6IFa9wvqVegA:10 a=GoEa3M9JfhUA:10 a=3lpVkEXhDBfPzqlo3TUA:9 a=CjuIK1q_8ugA:10 X-Proofpoint-ORIG-GUID: mYfUVcnWatubL1_o415XJ-vsImUlJN4I X-Proofpoint-Spam-Details-Enc: AW1haW4tMjUwNjA5MDExMiBTYWx0ZWRfXxLbspeLZV1kT RmacHrSA1w9laOSxhizN0lKpWDfH7jmWXe9g8IEGji3iY4foVjw6fXcJnKHI5Yszaa1km98F4JF nUsA7vRqMaCJvc/F3MmdWFEVbQiVvS5EJVRbmedp2r/hNwJ6AgFiC3d+NaRpWy3dPgPuFwZRpRs 1FKgao/k60TBjt2cl0m9ytOTd9pZD2A+lNkx+vQx5ZGDBq1hHhY1u6qZ9JFmsfRvmJUkLsoDwHe ZVGVOzmIG1nBG+5RXR5uIq7ut6AyMyYaE9zf40t/b4UXQifLIN0khkOS3fvnk7WPhQ+bNWza5tC cTy12CqqcXARZK6M+Ei/A77kfqtCShMgxVteM709HzSOITkK9xm0dmEWvR4Po42HJQWreEeyQrq /cknzPHgTpQgeoocpQaRX+UkWvVi70byRKDVeLWiX7jyAJmmz1P0H64xChd1tg65tERGPWt5 X-Proofpoint-GUID: mYfUVcnWatubL1_o415XJ-vsImUlJN4I On Mon, Jun 09, 2025 at 02:40:09PM +0800, Qi Zheng wrote: > Hi Lorenzo, > > On 6/6/25 6:44 PM, Lorenzo Stoakes wrote: > > [snip] > > > > > > > > > > > > We could in theory always add another callback .pmd_entry_sleep or > > > > something for this one case and document the requirement... > > > > > > Maybe, but the SRCU critical section cannot prevent the PTE page from > > > being freed via RCU. :( > > > > Idea is we'd fall back to non-RCU in this case and take locks... but then > > ugh we'd race everything RCU and no it's all or nothing isn't it? > > So maybe the RCU+refcount method is feasible. We can release the RCU > lock after incrementing the reference count, which can ensure that the > page table page is not freed. Oh interesting... will note down for when I take a look should you not get to it first :>) > > > > > Overall - I will stash this response somewhere and come back to it if > > somebody else doesn't in the meantime :) > > Thanks! > > > > > > > > Cheers, Lorenzo