From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from BL2PR02CU003.outbound.protection.outlook.com (mail-eastusazon11011014.outbound.protection.outlook.com [52.101.52.14]) (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 90228247DE1; Tue, 17 Mar 2026 01:58:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=52.101.52.14 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773712700; cv=fail; b=RDRvhY6nXGHcoUQKWoiTQEu+b/piG9fE18yK3Yvx7JOjvJct4SDcHN+EwrLyXfh9g4eWlJ+0WpMWgQ/IkYBNioK5sHW+J1hX8Kb+8gTechLWV0waH+t7eoTERflyj6cZNReXXR03lfzzb1JC8M5pNQWRBL+cGJ0R9NRnN4FF3ao= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773712700; c=relaxed/simple; bh=PHcUStEndTFaP7ZEnPa+nUjL+xEC5T7WFlLw66jOQGU=; h=Content-Type:Date:Message-Id:Cc:Subject:From:To:References: In-Reply-To:MIME-Version; b=JrQGppI08mARtjEALO4omhQYYW/0k8+Q8xPwzepbkxAhICBhB1sqhrNrkuKE3W4q5n4UjIWi7tRudrlDjDtqKVc6conA9QxoHH0hGGZrxcR9XccBZ/hSjPvMR0uhcDVMeKrvMUzTIz++XDD/CRDQIz57PczoXTwh9qDju11snSo= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=nvidia.com; spf=fail smtp.mailfrom=nvidia.com; dkim=pass (2048-bit key) header.d=Nvidia.com header.i=@Nvidia.com header.b=gNidhsZM; arc=fail smtp.client-ip=52.101.52.14 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=nvidia.com Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=nvidia.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=Nvidia.com header.i=@Nvidia.com header.b="gNidhsZM" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=FUqxFubqcQ+fKj5nW4zC1doouJVGmSQ+ji63RPa5gIc7LWQs4r76rpth47c1tejJMxrYnbCWXSrJcKsUhyj7y+XsreLv3axZOuGR7n8l/ZqQTcnRvClqEVecR7bBZg5o8A6YeRPSv9LJmsuUTlNPjVr1bAlAiJHYtbNDJ/3y1agNGECBFFNB87p1hp1VSAxZ7Rjri36B53H1tu2CpVPvke2RSVfcUsNLJCnBgYl1m7oXHRv6qnHcQjsrG7SZ8X1uELNGcb9kiEqE/rn3J9qf9W/K3H3nwVtiIcnjLqbR+qSj8pLat/IvTHGdK4+aeNy73PCOW4z72ozxeSRTi5kgsg== 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=PHcUStEndTFaP7ZEnPa+nUjL+xEC5T7WFlLw66jOQGU=; b=WuQXm5CidfbhUmiVxe9s5l+16kE8JzzEJsnSxaQvxjOFUUjxVlJE76/IVTYNNNKieybJyB9zcX4jjYsB/FDhE6CwE+a7yCswIH1FAFR8d0cr+JcuerQNbLrv73T79al9ALTRxgvUBfTTwyGT9hFXTDV8wkTy5o3M5qViipOZzk+EpZasZW7fxrWTsc4mP18yJzkpEI+kxT7uO07ByilmQ6ciSviNrGiQ37o+E83bjhbJGvcJHqJxXaRHFV2h7iyQRTyzpUXP7mO+QaQ8TfQ0If4cDbChyJBave/LjJfdXJgMjPDH8xKC3tcAaWZB7VZgTBb44iXuZXi9tjbLzBEBHg== 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=PHcUStEndTFaP7ZEnPa+nUjL+xEC5T7WFlLw66jOQGU=; b=gNidhsZMbA3ix3GdCZ162H4KCMaAEAcqkRQSxVYCFvr1tnqeLh4+hCFzDKGDdfN1KkK6cqlWkvspIzZampt+AdZ8hiQsJbwEDvyo0IFqEth0wskXN28VGYSxm3Swl7kE34UHhR96iU+N1B8Tj1moift8zJsQeJ7U4Oz9FVM9LgSa8l6vFUHo18K3t8M4HAgZaCBInQCdJhjF48MSCk1GgkZT3ILmDw4h5hVs3oCxGExDTyT4UAhXUYLofecIrwpI05f3hNCtPHSrKM/QieHagZKn12K9O7WNPNydiBNjvCHjGD8rPQV0vaBBobjDFrjl59858QAqb5j3s00ZV6mUNA== Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=nvidia.com; Received: from CH2PR12MB3990.namprd12.prod.outlook.com (2603:10b6:610:28::18) by PH7PR12MB9075.namprd12.prod.outlook.com (2603:10b6:510:2f0::20) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9723.17; Tue, 17 Mar 2026 01:58:14 +0000 Received: from CH2PR12MB3990.namprd12.prod.outlook.com ([fe80::7de1:4fe5:8ead:5989]) by CH2PR12MB3990.namprd12.prod.outlook.com ([fe80::7de1:4fe5:8ead:5989%6]) with mapi id 15.20.9723.016; Tue, 17 Mar 2026 01:58:14 +0000 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=UTF-8 Date: Tue, 17 Mar 2026 10:58:10 +0900 Message-Id: Cc: "Joel Fernandes" , , "Miguel Ojeda" , "Boqun Feng" , "Gary Guo" , =?utf-8?q?Bj=C3=B6rn_Roy_Baron?= , "Benno Lossin" , "Andreas Hindborg" , "Alice Ryhl" , "Trevor Gross" , "Danilo Krummrich" , "Dave Airlie" , "Daniel Almeida" , "Koen Koning" , , , , "Nikola Djukic" , "Maarten Lankhorst" , "Maxime Ripard" , "Thomas Zimmermann" , "David Airlie" , "Simona Vetter" , "Jonathan Corbet" , "Alex Deucher" , =?utf-8?q?Christian_K=C3=B6nig?= , "Jani Nikula" , "Joonas Lahtinen" , "Rodrigo Vivi" , "Tvrtko Ursulin" , "Huang Rui" , "Matthew Auld" , "Matthew Brost" , "Lucas De Marchi" , =?utf-8?q?Thomas_Hellstr=C3=B6m?= , "Helge Deller" , "Alex Gaynor" , "Boqun Feng" , "Alistair Popple" , "Timur Tabi" , "Edwin Peer" , "Andrea Righi" , "Andy Ritger" , "Zhi Wang" , "Balbir Singh" , "Philipp Stanner" , "Elle Rhumsaa" , , "Eliot Courtney" , , , , , , Subject: Re: [PATCH v12.1 1/1] rust: gpu: Add GPU buddy allocator bindings From: "Alexandre Courbot" To: "John Hubbard" References: <20260308180407.3988286-1-joelagnelf@nvidia.com> <20260309135338.3919996-1-joelagnelf@nvidia.com> <20260309135338.3919996-2-joelagnelf@nvidia.com> In-Reply-To: X-ClientProxiedBy: OSTPR01CA0080.jpnprd01.prod.outlook.com (2603:1096:604:218::16) To CH2PR12MB3990.namprd12.prod.outlook.com (2603:10b6:610:28::18) Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: CH2PR12MB3990:EE_|PH7PR12MB9075:EE_ X-MS-Office365-Filtering-Correlation-Id: ed86cb07-a5d9-426d-17f7-08de83c8a637 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|7416014|1800799024|10070799003|366016|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:CH2PR12MB3990.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(376014)(7416014)(1800799024)(10070799003)(366016)(22082099003)(18002099003)(56012099003);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 2 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?RnpDS09Ja1JGNEM2dlhkQ3pKQWprMjlNNUlGaXdzNlF0YUN5c05iemMvWjFT?= =?utf-8?B?NUNGNVJVSnloZFFzckw0d0NQTDhTanJXcjY5aUI5ZXptZnBPMDFJTXpSaTFY?= =?utf-8?B?N2xQeVY3amZ6ZEJqeFpmV1hWSDUvZm9BN0F5akIxS2VOOE1RdHZ4ZVN5a2gy?= =?utf-8?B?UC9iTmtvTTdkY2x4c1Q2OHU4WHJ0NC9yZzV0ZHZ6NGVrdisxUHAvM2FFZWd1?= =?utf-8?B?Y2Y4MU83RHlrZ1E3SlNGK29NSVlIWUpCUllxMUplaTFaMCsxTVFsMGVyRWh3?= =?utf-8?B?T1l4UnI2aWpPMGk1Z1lERGMyZC9qZU80MklKOFAyK0oxc0FDQklEdHVlbUF5?= =?utf-8?B?Y3VQWTBkMVNTQmtOSGRGWnZ2M3MxaStLemdEa0VwS0MrK3Y1K1NhNXU4QXE4?= =?utf-8?B?QWUxazNDU2JVZHNvMXk5VmI4WkovSU1pY2ZpQ3BTS1A2SzhQVG1VYUU2M2dl?= =?utf-8?B?M2xXMEVwRkRCSTVXNExFSm1VbnY2b3I3ZVBaVWhhdkNvTUU0OU8wNTRtSU01?= =?utf-8?B?Z1c4RzJWZ3VVNGdaYmhPRkFJNFRTbUdkRkZxekJxSXBtclRCZFl0bndiTE9Q?= =?utf-8?B?eW82QW9nZERMb0xmMDhxYmRYNjZtOU41QVVEWnpJYUpZRC8zajcrblhOSC9a?= =?utf-8?B?K2lRY05HYVgxL0s3ajRqc0owRVdBTUd4Y29tTlJOYUtKWXpKdHh5VXBVNTN5?= =?utf-8?B?YUV0a2c4dG11WnIzUGpwZDFHRXBQUUhxZUtnOXRlV3FuaHpSdTBzSG5lS1pz?= =?utf-8?B?QzVIYWh3RWQ5OHJ2M2JLQjJSVnRnQzh2cWlSZFlVcWhJYUxLYnRPZXZwV3dX?= =?utf-8?B?Y0pBazEvR1REMUNFeFBQaTI3a2pmWjIwT0c3dGxXRzZBYkswZ1Y5VG54UDRF?= =?utf-8?B?anAvc1ZkOGcwTWxqb01sNThXeERRb21ER0VFaDFCbkxQSjFXRmR1bkd6TTEw?= =?utf-8?B?bE9CNVB5ZTN5SThickFiNGtzdkU0d2lUcEI0ekVOWDQ1RjNrcHRxQi9aNitp?= =?utf-8?B?ejl6aUxGMG5BVGlTb1ZjR094MHNrbWlWaFRFTkFSVE1QbFpyMkxJMU9QR1F1?= =?utf-8?B?bWtTZWZHcUl4RFg3VndQcE43dUJZYStMYWkvK1VXeFJ0enBQSWVGeTh6WDV6?= =?utf-8?B?aHM4Nm90dHk4S1lxWVd6NXR0V01odElpMlZ3cFIyeVN2dC9nOUgwbTNqZmFJ?= =?utf-8?B?RUlyYWtZc2ZvV05rMStFWWxXdXlyZmZkTys5d0FyeFFQUEp3WUVDWEl3YXJm?= =?utf-8?B?T25VTkNwY25sa2oweW51UU1odXhUbW9DSXpRVm8rYjVGVzcyd3lIQXA5ZS84?= =?utf-8?B?eFlRQll2SFVOT2g1NTB0dmxqMDVsOGdySlZ3WE9oRlpnZ2hPU0xETWw4VTZM?= =?utf-8?B?aXBJMUtKdTZzOUM2cUM0UjBpSE5EelE2YXYrQ2k2R2F1a1ZmVzlJanFyTEJ2?= =?utf-8?B?dmlhcmIzcnRkeEhxWUVGQmh4YjlRcVYrejE3cVRxRUp3VENTM3ZlNGJhc09X?= =?utf-8?B?cU55T2llclhTS01lMWlWTEN3anJ0bDNPNXVTTElUZEZhMHVISktmS050UVl3?= =?utf-8?B?Y1FzMzYxemZOYXlQNnVkcUxYZEdWZzlDZHQwQXUzcUEzeWVrS0ptRXFDTVU3?= =?utf-8?B?OHBVVENpTXRnMytObEdOdnd3eFMzaWszWS9QNUZFa0lhVmZoWmFhbGdzMlZZ?= =?utf-8?B?L0E2MXJhV3VGajN6UENZckMrQmxQanljZE04aU5nSHRPUUJ1WFVvR1VWWW1a?= =?utf-8?B?K25KclV3TlcrTEhCWDdETHRFOFQxaVpGS0ZyQ085N2VxV24vNUdFLzdEZmJ3?= =?utf-8?B?TE4wWXErbmtTQS9hU21janJRc0JJMEdpMDNRSFJGZUJnWFhSeTg3SkU4OTR6?= =?utf-8?B?Tk1ud1dDMktSbEZtblN2RTZSU1RSV2hXL3ZndUpBSGtNL1pta055NmhlWVVo?= =?utf-8?B?VTBUMlN2cDRTalpKdHJGQ1R4T3N3Q2VWVjlBZ29rMTZQZVpUbkloZnUwL2ht?= =?utf-8?B?U3RDOVcyM0NqUnE3ekZ1ZjFxYmhmNUpmdmFnNWt5blVhcWsrc01mY25QM3Bw?= =?utf-8?B?TTM0WkhTc0pWeDVnYzZGcGNlb1JKOGJPejY1eWxjZklwOFNuTzEvWkxKLzdv?= =?utf-8?B?TG1va21HSDhxWTB5cjZhc3pMTWlGWlVxYVlkVmxZZnhwblpkZUJwdkpoNVA2?= =?utf-8?B?ZUllZ2dYb2pJZk02RUpRMHFFS21taWwyUlVWMWwwaVVBcGZ3Rm1JeVpFcVJ2?= =?utf-8?B?eTdIUkU1d2V2dFh6Sm84YUxKVmkyMy9wa2s1SWZGUERnNm9HeURSQ21hclQw?= =?utf-8?B?dzcwM1BmcUVNK2U5T3oxRHVaZkNtbFBnL0prUTlZTi9RWmdZdGVkTDBTakt6?= =?utf-8?Q?2kD5cgGSgi5A4obJHl/1PpygbhRrrSZm3ygVZFYXPB9Go?= X-MS-Exchange-AntiSpam-MessageData-1: x4YC56m2S7sfbw== X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: ed86cb07-a5d9-426d-17f7-08de83c8a637 X-MS-Exchange-CrossTenant-AuthSource: CH2PR12MB3990.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 17 Mar 2026 01:58:14.0312 (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: JdSUxLzzZuLjA5k//D46+ydMU4xS3O8JFMP2bVtXrw5G2XnkVCFRJem7cDPZQEezmMxP1tUhQ170jRAUQHqVdA== X-MS-Exchange-Transport-CrossTenantHeadersStamped: PH7PR12MB9075 On Tue Mar 17, 2026 at 10:10 AM JST, John Hubbard wrote: > On 3/16/26 6:02 PM, Alexandre Courbot wrote: >> On Tue Mar 17, 2026 at 3:51 AM JST, John Hubbard wrote: >>> On 3/16/26 6:12 AM, Alexandre Courbot wrote: >>>> On Mon Mar 9, 2026 at 10:53 PM JST, Joel Fernandes wrote: >>> ... >>>> I'm a bit torn as to whether we should use a `u64` to conform with the= C >>>> API, but doing so would mean we cannot use an `Alignment`... >>> >>> Alex, have you seen my Alignment patch [1], for that? It's sitting=20 >>> around with only Miguel having responded, but seems like exactly >>> what you're talking about here. >>=20 >> Not exactly - this patch provides a shortcut for creating an Alignment >> from a u64, but it doesn't allow to store alignments larger than 4GB on >> a 32-bit architecture since the value itself is still stored as a `usize= `. >>=20 >> But that's really a theoretical worry of mine anyway - nobody will ever >> work with buffers larger than 4GB on a 32-bit arch to begin with. > > Actually, in the CPU world, this claim was made early and often, but > turned out to be wildly wrong! That's why we have "high mem" in > linux-mm (a constant source of suffering for kernel devs). > > The 32-bit systems designer do not feel constrained to keep their > memory sizes below that which they can directly address. :) Yet IIUC PAE still limits a single process to a 4GB address space (and `usize` is still 32-bit anyway), so hopefully we will be spared that pain. :)