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 lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id DC242109190B for ; Thu, 19 Mar 2026 18:24:42 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [127.0.0.1]) by lists.ozlabs.org (Postfix) with ESMTP id 4fcDcn2GM4z2ypW; Fri, 20 Mar 2026 05:24:41 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; arc=pass smtp.remote-ip="2a01:111:f403:c001::2" arc.chain=microsoft.com ARC-Seal: i=2; a=rsa-sha256; d=lists.ozlabs.org; s=201707; t=1773944681; cv=pass; b=Ncqz2sqLhfrTK/eAEHIm2zPSlyLVSShKnb5tccd1mrMPgPVwY4RDW/sCweQ1nLMfGeUp3FFpeWwFuVVcfAYqsRBgMjSUE+7ZxvPhDhrJD1yVdFtaV+H+Lu/WbgQw6Yhp55PGwqM9t+Z/PZkNintz2P6WeyVdcRWtnW5rj2YKEG1+jIXFrUr36nEc7G+/+DdES40cvjriuPjeYKEfbP4O8OsyE2LaeZhjhPbuG+0EX38biiZ1Bxkxce2zpm+dxwA5/aKVWzIoVvwLF8niQJvTWRKfm6TYjwdIM9OscwEaPEGuyVyBDPlEU8NE46FW6RlNr8pE1Kk2ou85VmPFLN7OpA== ARC-Message-Signature: i=2; a=rsa-sha256; d=lists.ozlabs.org; s=201707; t=1773944681; c=relaxed/relaxed; bh=2Mklnx57YIr1iiDE3OlGnFRnz50EoccTLYXpJqKwHiI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: Content-Type:MIME-Version; b=CGsmHzkhcm7q8dWkr7FvgOcRR/+iLlZuR4BTHYmDhoymUMRcYQgTRRfAIagV6O7fiv+Twn81X4Wm09R37IjrJqRu22fC+DxMBG050cuc5Vt39OZG6WJD0F55v1BCoL2X4hhtIADzppPZNRuhzkP+oibWHx0YFz/A5Y+G1Dil984QPHc3qwuhlSZMBuFJ4YF7lXYcniwB2mWEpHg2Qx+7PABHxtQf04/L0e3Dji/CxoD+iRzVaChPM5aDVvx9/uv3A0eCVj0kycSuQ9rkNJ5HqX5NlivCarfvnE586aDps3JyM4Khss/6jE9Zabvcc7XaNP86feIrEEPFq4TVVY3O7Q== ARC-Authentication-Results: i=2; lists.ozlabs.org; dmarc=pass (p=reject dis=none) header.from=nvidia.com; dkim=pass (2048-bit key; unprotected) header.d=Nvidia.com header.i=@Nvidia.com header.a=rsa-sha256 header.s=selector2 header.b=UQVEcaTu; dkim-atps=neutral; spf=pass (client-ip=2a01:111:f403:c001::2; helo=sj2pr03cu001.outbound.protection.outlook.com; envelope-from=ziy@nvidia.com; receiver=lists.ozlabs.org) smtp.mailfrom=nvidia.com Authentication-Results: lists.ozlabs.org; dmarc=pass (p=reject dis=none) header.from=nvidia.com Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=Nvidia.com header.i=@Nvidia.com header.a=rsa-sha256 header.s=selector2 header.b=UQVEcaTu; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nvidia.com (client-ip=2a01:111:f403:c001::2; helo=sj2pr03cu001.outbound.protection.outlook.com; envelope-from=ziy@nvidia.com; receiver=lists.ozlabs.org) Received: from SJ2PR03CU001.outbound.protection.outlook.com (mail-westusazlp170120002.outbound.protection.outlook.com [IPv6:2a01:111:f403:c001::2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange secp256r1 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4fcDcm17qVz2xVT for ; Fri, 20 Mar 2026 05:24:39 +1100 (AEDT) ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=MkEGhQGcGTFPDDixQgXShefw65STgtRoc02vCMiNZ5WgBaE1e7BFEa44aTK0WHpMZgxw+wE4JtfsloF327jTDptmE3LldPTsNgfNGVJEzCcHOKd8FRd05U0P2nYxJ8vE/N+QBracAQPc5nDsMSmekulJlub35IHOPNLJ6Upj+zQ0nWFiRl00crM+cqqDyGTumYz4v4itPTxPR8KF/mpCjg6rPzNfCsXZ8g3HuFYaCet1DSjrQFg8LClJoGO4tiOkLifMtE2J+8KUbZXA7KBUGLKEYFXSIMkONSXCoO5dCVJBgW24QS3qZbjsTCtsQngeAcV5UgHz8dCzTl/d588RaQ== 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=2Mklnx57YIr1iiDE3OlGnFRnz50EoccTLYXpJqKwHiI=; b=PGU1mW9Lb98DPemX4T6vzE7FeHsJqZ4zu0bb+qeTBKuvA5BhpX2tTt3PamAPj2xkC/ggagt7PxsKVhaW36z7rWeQEc/sb+T78FTrRtgOmdWRRiPT8YAZoJZ4iDZba8Rx2P/EiHWkTHt9uMk7/m6eTiJAR8lIHI8kvxUnOeM6vL6t/TMVLgRn8NbGpMBBKnVZcHIPxMHsTvHgF1H1Ny3tSd1CVY2leOCL4/ucxaLSRH7+CYBTB8IDHWHrdvsgaz9Xk6DiI7WAxN5g5Jq+aIH9Jk97aNKiP9hMBNeeo1XHlOCATcHRAUidNv6yhRmfmOqvV9zGY6YQ45KEEhCKFXHWrA== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=nvidia.com; dmarc=pass action=none header.from=nvidia.com; dkim=pass header.d=nvidia.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=Nvidia.com; s=selector2; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=2Mklnx57YIr1iiDE3OlGnFRnz50EoccTLYXpJqKwHiI=; b=UQVEcaTu2nQhz5aQoW11LBUxQQwhINeBEs7XSsiv/nQTHNEvy/QkfLZrclhwJlwIvPDbtf5eO52g5m1MFoZjJiNfz9kgHJ0yA4AVY+BefvJ7uve2GBOjX/IwM+gJ/v9tgp/V7stDgPutwZ0BwPfVXvD0LOWTz5fxQirM6DTzP9VC8veDTbOLOUOjCGnlKoL+Zbe8oc2U6xNcEznGUo87mGm+5/cfoaz5BFcmJrzyMm+57RPhdJl5183+ffkjeQQlv0clEUk+/yR23apr7KAUHz3JhLv3plUNMoxiuduDOyxFmwiJSudDKe3Dv8+46iMsPYvcfoBBR7skj2sZnmTWSQ== Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=nvidia.com; Received: from DS7PR12MB9473.namprd12.prod.outlook.com (2603:10b6:8:252::5) by CH1PR12MB9624.namprd12.prod.outlook.com (2603:10b6:610:2b3::20) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9745.10; Thu, 19 Mar 2026 18:24:06 +0000 Received: from DS7PR12MB9473.namprd12.prod.outlook.com ([fe80::f01d:73d2:2dda:c7b2]) by DS7PR12MB9473.namprd12.prod.outlook.com ([fe80::f01d:73d2:2dda:c7b2%4]) with mapi id 15.20.9723.016; Thu, 19 Mar 2026 18:24:06 +0000 From: Zi Yan To: "David Hildenbrand (Arm)" Cc: Gregory Price , linux-kernel@vger.kernel.org, Catalin Marinas , Will Deacon , Huacai Chen , WANG Xuerui , Madhavan Srinivasan , Michael Ellerman , Nicholas Piggin , "Christophe Leroy (CS GROUP)" , Paul Walmsley , Palmer Dabbelt , Albert Ou , Alexandre Ghiti , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Andrew Morton , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Matthew Brost , Joshua Hahn , Rakie Kim , Byungchul Park , Ying Huang , Alistair Popple , Sebastian Andrzej Siewior , Clark Williams , Steven Rostedt , linux-arm-kernel@lists.infradead.org, loongarch@lists.linux.dev, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-mm@kvack.org, linux-rt-devel@lists.linux.dev Subject: Re: [PATCH 1/2] mm: remove CONFIG_ARCH_ENABLE_MEMORY_HOTREMOVE Date: Thu, 19 Mar 2026 14:23:57 -0400 X-Mailer: MailMate (2.0r6290) Message-ID: <285BC754-4B98-481E-96CD-72F7865423D2@nvidia.com> In-Reply-To: References: <20260319-config_migration-v1-0-42270124966f@kernel.org> <20260319-config_migration-v1-1-42270124966f@kernel.org> <1559C268-444B-4A64-A0B8-21B2FE49A5E2@nvidia.com> Content-Type: text/plain X-ClientProxiedBy: SJ0PR03CA0057.namprd03.prod.outlook.com (2603:10b6:a03:33e::32) To DS7PR12MB9473.namprd12.prod.outlook.com (2603:10b6:8:252::5) X-Mailing-List: linuxppc-dev@lists.ozlabs.org List-Id: List-Help: List-Owner: List-Post: List-Archive: , List-Subscribe: , , List-Unsubscribe: Precedence: list MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: DS7PR12MB9473:EE_|CH1PR12MB9624:EE_ X-MS-Office365-Filtering-Correlation-Id: c3929525-cded-4ba0-1c6c-08de85e4b4b4 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|366016|1800799024|376014|7416014|22082099003|18002099003|56012099003; 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:DS7PR12MB9473.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(366016)(1800799024)(376014)(7416014)(22082099003)(18002099003)(56012099003);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?MprU0HWyElJKuIqYkXE5BjXyF/Jq2nahQsjDK4NBSFW6rCpJK/Pr0g1uJalj?= =?us-ascii?Q?+KaQ94KpyQvUElM6Jt6ZkhetNzmtxNc7sJGPYIx5rLGBLpU8RMApJv9gxXbW?= =?us-ascii?Q?82kXpcQWup8wCho6IlbBwZFi6FlcpwTZb3kBIAKbqTRhWNY9XHdwcUB+VaGR?= =?us-ascii?Q?kwsQnk+TUhYPSFwnZX8oggShYUZMysDoW73CSgjyZdY7pkAR4NO25QAmm5Gx?= =?us-ascii?Q?3iz4lZk9/pqpqTTZNlzVwtHt7mHdpo+wgVbPuzZKP04gRS7zg/l0P2AL3dLg?= =?us-ascii?Q?4sVeMtm+KSSgBZLla5ePfc0UTHbYIckHc53p0BhY2rY1QBiv3kHvUBW8cPHc?= =?us-ascii?Q?mgZ+YOBU2fK/p49Hc0UsKhBKQHZEjOrjunEfy0bt7k7Nj+3GFmap0OBfmRzY?= =?us-ascii?Q?ff8Ey5WDQ4B0VffacDSJQGWRAOlgrWOr6oLQaY8ULgPq2rPCXORWspVSVsxS?= =?us-ascii?Q?ux1CSzXvIXpwmnKMJ/XVALGSZ30FjObvRxywuh75VOfgBegk8QxtnuOH0Adj?= =?us-ascii?Q?XvA1j9IFN9FhuQSR76Amk0yaGe2UFzsQEMRbNubVYbK3wJxptzUchSRAI5fx?= =?us-ascii?Q?t3lvIIU/p8+34aS3/OFRMyLvKUf+RolqbCUkGnth5js+KH/DCz+s2/ci9qOE?= =?us-ascii?Q?H2kJWzU1fmUkqHJdGW7aNHySh+HN9T1xkQaEWc2iflnivHRVESxKS5SpNiB3?= =?us-ascii?Q?JlkN1YTwdwun0h9rI33gur6bbw7+3bKL3c/6EnDdGFY8hSxyA24US5atFX5o?= =?us-ascii?Q?7aj8EH/E/lxl63/qXUMIFppo2DvQw46ewu7/mIJ0FtTvY4I3vFwFSYI/UpZ1?= =?us-ascii?Q?LMI9rZwMcvk97ywItWfvGXOCAIjCp6Ewpi2Ua+YPb6YjJW4sEZML9V/JQBvk?= =?us-ascii?Q?TOPfzO8cphMcSrFS9v3DZSqHcmddjq0nu1RZO/oI6MzhBO/VeIhoVFJ1smrI?= =?us-ascii?Q?hBhMvJDcoRnxHllj9fnG6cqjOJsC8Ma6Y7yO0SEa+Dz9hyQhSNFnipateTU5?= =?us-ascii?Q?s3HuRr7fy5goG37mbhZq+iSPFRLM3XgQp3BPq0Aq/76e9C32mfD1bRK0ETer?= =?us-ascii?Q?we21FJOO29wMsO9b+WcbvXPUgs0dq12kjEJ8+OvDI1PB0BPm1Q6wPyWph02v?= =?us-ascii?Q?XSgazbGbBUZnEc00dMr+w5dln/vW9q6YDdDfY9VfrAWaWgmFXfK/bvffTlXJ?= =?us-ascii?Q?VwQ1XY0z6yihktEJ9zYk9vEN6BSoaHLZuYBqBfGzLfoZgUIaabfljxercqbe?= =?us-ascii?Q?O5LnlVVMN1itNlLHQWIuGcth4dh+fwhoVBn12QfzLHYTCStoT6QqRvpYnUrf?= =?us-ascii?Q?XgkPVx2MBHQ5BMJpPEAB87edQxmoOXYnDgX81QwruIJ4MoV9i4bs7oAyoPkF?= =?us-ascii?Q?hVlvOyJJ6izp2nF2vlN/BqbMS3GXVZmazGn62ubCU0ro6G3zSWCV2S5fo7sy?= =?us-ascii?Q?282OhlZ0/TfpqjWZ1OLfsDV8/R4TDMDycPRo/bbb0IXtlEYbFhFDrs/vXV4O?= =?us-ascii?Q?bYDvlsfb/k6ZngPj3tiOmUzA0Gs4Uby03atUaRzAHVq41azlu27gDf9Pi4qx?= =?us-ascii?Q?Ji8S0oHd2Q3Q/IFdllp4siEqw7LTnLdjeITNSr4N8CTC5qNc/kOV6VTF5fMp?= =?us-ascii?Q?iHnL99sTWzat6fd70yD8q2UlD1ow0cP8oOuMrygYa2bcxrgBRnwgOyJ1I+rU?= =?us-ascii?Q?VPHfbANyqKZ2MPhAS6e0pG7yMAZmYKYiGqMuLVKpqdFYvb0C?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: c3929525-cded-4ba0-1c6c-08de85e4b4b4 X-MS-Exchange-CrossTenant-AuthSource: DS7PR12MB9473.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 19 Mar 2026 18:24:06.6686 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: TlZZYiDcUu5D5bgdyLdrnKcTSvVjIkGwNDCy+HWpoRVWVd3DPchXAXDBnH5bUKqQ X-MS-Exchange-Transport-CrossTenantHeadersStamped: CH1PR12MB9624 On 19 Mar 2026, at 14:15, David Hildenbrand (Arm) wrote: > On 3/19/26 19:12, Zi Yan wrote: >> On 19 Mar 2026, at 14:08, David Hildenbrand (Arm) wrote: >> >>> On 3/19/26 16:24, Gregory Price wrote: >>>> >>>> HOTREMOVE has long been a thorn in my side, I appreciate you cleaning >>>> this up. >>> >>> On a long cardrive today I was wondering: do we still need a separate >>> MEMORY_HOTREMOVE >> >> You mean merge HOTREMOVE into HOTPLUG? > > Yes, only have a single config. > >> I wondered the same. Is there >> a reason to only have HOTPLUG without HOTREMOVE? > In the past some architectures (e.g., s390x) did not support HOTREMOVE. > Then it made sense. I'm not sure if someone would want to build a kernel > with HOTPLUG but not have the bit of overhead for unplug+migration. > > So I would guess nothing major speaks against it. Sounds reasonable to me. Best Regards, Yan, Zi