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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (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 EE5F1EDEBF5 for ; Tue, 3 Mar 2026 23:54:45 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 67A8B10E008; Tue, 3 Mar 2026 23:54:45 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=Nvidia.com header.i=@Nvidia.com header.b="CJIeMGrI"; dkim-atps=neutral Received: from CY7PR03CU001.outbound.protection.outlook.com (mail-westcentralusazon11010040.outbound.protection.outlook.com [40.93.198.40]) by gabe.freedesktop.org (Postfix) with ESMTPS id 38A3810E008; Tue, 3 Mar 2026 23:54:44 +0000 (UTC) ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=FSldBE0Y9FvvMG3VNAFgeM73NgUluDl049dNo7oxSDotSGf+aYPyZss4AVkqiVU+s7gfk0RIaERcTImA/yn5f6KWDHFcCzRHtjy2+Ksg2pStQiquO2d6hGns19VF5TvzmGSf3yCpPhOpXYLLFyA3saYT9Gjgz2a+3EEhTdZozABcNLCbu77nhpgcxwXOJNPm6LMAz/q8PS4A1EIlj3UNLtmE4rDHNcTcbW8ElwSL0MSe3CbvoDfBZqFwpCQm6YmHhj8KHQy95ETy+XZxx6zwZ1zNrIACVEZ8DzjnqKgEltrsrjbwHn+ApZ2rUoothC0IWctR8cA69YX2EcJz3doilA== 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=9qld5EB9i87A1m6ld3RgIbU4qDfexSmfO5tAZYCXvNE=; b=IKbn8dsDXtKJiiULf/h0tw8HSIMQBAJi7RvfeJcatfiLei+JGeQmdsWi7V+bEG20mHw4G+HADV/eT7lAEmLVlOKEylwhS1fEOs/xN285zttLLph45AVSSyGGdXdHdlQqpzlFeiGa7ipnjvuhNsUi0o6vCg/6zHv2K94DZ860I+zmIiSHa2pDqQwTGxF7vRy1EB9M7oB+XFWaWlBiRjhs4Ha7XZLS1NXp8ukWUMChF6zvkT3syHoINlKrwjGl9hpM8gY3UYy8tlkA5n9+kIeG5faLep7CCOXfqDoQU1kLEPO0MizzwOaYpV83afJPZSpBkQj1Wq6yn7zAl6Iz3FJHuw== 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=9qld5EB9i87A1m6ld3RgIbU4qDfexSmfO5tAZYCXvNE=; b=CJIeMGrIHJVEWcBl3/GB/sUg06pdbNl1O/GHDY7/PZ538ytNNnBwqRsvnmkpuih0mEWg2wCEoMkYr3UTWxZ6qfxy5E5Sxt4rRvF8cKLqIV5Jq5bvXpdP3TrHsN2J4L1PNg+Tb7pkDDmnDdzy9Wl4PJhBK5oBGNXqrlsajZuNEA/MZO1+9ltmH0Xlfvm2X8pZQrKLFmTwDvy5mtKfsAFXxmOWIKcm9jib0use4Div8R9+AGYs+BhpyR1ZgB8ztYoGmc+G89lWCUWE1oTWthG6gR3WzUvxvowvT/46E0U77LAx8vLtUQOhE2hzjMIHbb4JNXCWop+ROpa2vl5Boe7l7A== Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=nvidia.com; Received: from DS0PR12MB6486.namprd12.prod.outlook.com (2603:10b6:8:c5::21) by CY8PR12MB7099.namprd12.prod.outlook.com (2603:10b6:930:61::17) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9654.22; Tue, 3 Mar 2026 23:54:40 +0000 Received: from DS0PR12MB6486.namprd12.prod.outlook.com ([fe80::88a9:f314:c95f:8b33]) by DS0PR12MB6486.namprd12.prod.outlook.com ([fe80::88a9:f314:c95f:8b33%4]) with mapi id 15.20.9654.022; Tue, 3 Mar 2026 23:54:40 +0000 Message-ID: <8a7510fe-758d-4223-b1d1-8b7f8afdbe18@nvidia.com> Date: Tue, 3 Mar 2026 18:54:38 -0500 User-Agent: Mozilla Thunderbird From: Joel Fernandes Subject: Re: [PATCH v8 11/25] gpu: nova-core: mm: Use usable VRAM region for buddy allocator To: Alexandre Courbot Cc: linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, nouveau@lists.freedesktop.org, rust-for-linux@vger.kernel.org, Nikola Djukic , joel@joelfernandes.org References: Content-Language: en-US In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-ClientProxiedBy: BL1PR13CA0257.namprd13.prod.outlook.com (2603:10b6:208:2ba::22) To DS0PR12MB6486.namprd12.prod.outlook.com (2603:10b6:8:c5::21) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: DS0PR12MB6486:EE_|CY8PR12MB7099:EE_ X-MS-Office365-Filtering-Correlation-Id: 8f6f5aa0-8a8d-426e-3bd3-08de79803bda X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|1800799024|366016; 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:DS0PR12MB6486.namprd12.prod.outlook.com; PTR:; CAT:NONE; SFS:(13230040)(376014)(1800799024)(366016); DIR:OUT; SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?SUFUei9jOFlnVG1xMStKS2JVQnA0UXIvQ1BGMHhWdE5oczRmaHJ3VVFuY1I3?= =?utf-8?B?U015UXRMYmdwcldQeGwwdW16aXQveUN4bFk3N1VCY3B2UkRNMk5yalBlbExN?= =?utf-8?B?NnN4VS9udGxjOHhKZklOY2pSSEpjdXdNMThDSlNyZ2w2aERTMVJBb2VKVUJ1?= =?utf-8?B?VXAxOFYzeUFzdVQ5S0gxYVF0TERBWlBncG16UTZsOUFOZkZlZWp4cU5TWTB3?= =?utf-8?B?cGpqNzdxMDc0bURjWUdZZXFsOFBzMzBDSHBkcnFtR0RRMWVLSXRYSmwvTnNj?= =?utf-8?B?dFlVS2Vyb2dzWDZrOGxvMEhYQmVGMzVVakprRHV6cWF4VDlvYlNXWVc0d0tG?= =?utf-8?B?SUNLTVBVdkQwS3RYbkM5RVM4U1U3eTJRM0UxZGNweUFqMkpYZWJzY3E4dG9t?= =?utf-8?B?UjV5ci9JbDhvYklOU2RmMmEyOGZnenRrYUswY3JBVjUwUGp6eDU1aElnZmpj?= =?utf-8?B?OWFWVmhzdkpZMTVzS2JRUGw5MG4zRGRnbjFES2Q2UzNrSEN3OWVZM0QxYlF2?= =?utf-8?B?STBCZ0pRRWFDQWEraU9FR1owVDRlZ2wvMFhveCtRZVZPSXVhM205OERBMXpn?= =?utf-8?B?bGdVeUFhVm5WSk5DaTlOeFE1WlBybDhza1ZiVVNWc0o3c2xzdlg1UE5BSHFM?= =?utf-8?B?b2dBOEVOYURodEQvTmFKRDVncmExWWg2cGhtdVJxSkJoWVhPcW1Za0RtWUV1?= =?utf-8?B?aDFYVWFuZjRsWjhZVnZCelE3S0ZFWFhlVVcrandlUU5ZVjhjMTM2aExwRkVQ?= =?utf-8?B?Zm5VSHQvdURBMkhlbmdXekxWallrby9STXAxbW9wRzdpTENwTWE3RWh6SFdm?= =?utf-8?B?RHZRRTNmNzkycmRzSEd0eUJ0RGlpTFFrQ0NuQk1wOEZKdm95Z3JRZGVBSEIr?= =?utf-8?B?TlU2ZmpBdjh4NnQ2K2lQRjUwN1VhMDhrSktnV0hXZ01CVEJpRmM1T2NWYlh3?= =?utf-8?B?WVVXb0lhTXk5bG5XSWxFZHpDcVhaYjUyZVlNRVB2emdlQjhHeEllZC93dUlU?= =?utf-8?B?SjdUYzdZbFRLUytxc1JTV2RiSzdJZEJaODh5MmlLRnZQNWJkQldxeGI3QnBF?= =?utf-8?B?NWxQdnFrSmpzaitVMWtnREdXditIcUtXYithOFl3Qk9qVDRZakU2TG8rY0dO?= =?utf-8?B?MVRpeEd2OUNsN0JRWjRZcU52VFVFMUljRFBaeVNkTjBOZkI0SlV5Vk9CUDFr?= =?utf-8?B?dGhhVkhpb2xyM3lSNWlWd3J0YVo5L2lpcktJTiswZVM1dUdpdW1NZldkZkJj?= =?utf-8?B?UklWOENnbEF6QjdkaXBER1hrV3Nqa09XWXdjckgxKzNRMXQzSFliSDFFb2R4?= =?utf-8?B?TC9UZEJyWEdQZ21DVTdsengyK05xUm8vZEtsY1c5UWhUbEYyOHoyblZQOHlJ?= =?utf-8?B?aWtZTHlsZkI5SlVzUHhjRitPZElOelJKUFlOcEczMSs0YmRuY3V0SVE4UGRR?= =?utf-8?B?MWhaNjBzVDNFc3VtSEZHRTVmUWcxN0d1QmgzcmkxcHJVY1lYT2U2azhkbk1i?= =?utf-8?B?YzE1TTd5b2diMTBiNVRQd2pDNUpjRk45S1BjLzIyZWRETmRkU0NyYTNHcEhM?= =?utf-8?B?L2g2dkpveXdXSmVtRU9VTEJkZWJGdEZWS2JXcXhTY2taQzVQYjg2cVg2NXBN?= =?utf-8?B?Yk40Z3Q1TC9DbXNyR1hIVUtMcXdyZ1kyYXlFYkZFa1p1SVhxTm0reE1xR3dO?= =?utf-8?B?N3lOL2Evdll1RUd5UFhGdHRXUFF2MWZIZkdiLzk3MEZHK0VFcTNqMzhHZDRr?= =?utf-8?B?N3ZSOU1Qdmx5a05RblhvWk84cExSL0FnUHEzaTdhZXFuZ3R4bTQrSjJvNzVz?= =?utf-8?B?TnBhdG9BcTVjQ0tzMXJFT0R4QVpNRUdKcVdYNEdvR0dURWIvVUhaUE5GS3lK?= =?utf-8?B?b3Z6c2NtS1NZOExxaUQwODRvNWJ5RCsraHJQMDlRL3VDK090L3pEZmNTaW1o?= =?utf-8?B?dExXRzk5YTloSGpEN08rWlNMNVVNSjBKTmVrYk5ISjh0a1Q4T2k0cjFxWVlq?= =?utf-8?B?WWJtdysyNXpaVkZ2em1LSWZDcFdLZ3NJenJnMWFkaVd4ZjlwaWd2cDlTcW92?= =?utf-8?B?NE1NMjFZR3czd2dxaThtZitWdFdoYkV0ejRVUnVCcmFYcnhuRjdNNUtwWkJW?= =?utf-8?B?TlV1Z3JKUWd6OThPSFFDalZjQndRaDF0WXBRTjg0RGxsaStBcHNWZWZmU2dn?= =?utf-8?B?SmFYekplVGthRXhyYUdMNW9FN0kwZk1PRDF0SUdsZ3E3MUE2UElvR3VrQXMy?= =?utf-8?B?OUl5YWN4U2JqM3ZOSjRmZVl2Q3lxM2hZWnppOWFFbUYvUFkzK3hoSE1rQytW?= =?utf-8?B?Zk5DOW1vNm9VWVh0Ny81emtiY0JtTGJnU3h1YlZpMlpKU2tvTDZVQT09?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 8f6f5aa0-8a8d-426e-3bd3-08de79803bda X-MS-Exchange-CrossTenant-AuthSource: DS0PR12MB6486.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 03 Mar 2026 23:54:40.3130 (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: gQM2VWYUJASmIU/N+iTmZ8wtU6ju4KWafu9DBWGJhCAv7EgkIabqoN5zhVZDMCav7ngOmXmrgJzDjCklrKPT5Q== X-MS-Exchange-Transport-CrossTenantHeadersStamped: CY8PR12MB7099 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Hi Alex, On Sun, Mar 01, 2026 at 09:56:30PM +0900, Alexandre Courbot wrote: > The chain through which we obtain `usable_vram` is very inefficient and > much more complex than it needs to be. > [...] > Which means `boot_params` and `BootParams` can be removed (and the > `Cell` import), and we have something simpler and more direct that takes > ~60 less LoCs. I like the simplification and I've made those changes! Currently testing further. One concern though (both with the original code and after my changes): `FbLayout` is ephemeral, it is computed during boot and then thrown away. I think the rest of nova-core should be aware of it. Other subsystems may need to know the FB layout in the future. Of course we can do that later, but maybe it will be less churn if we store `FbLayout` for longer term reference after boot, for usage say by future mm code etc. May also help debugging, say debugfs needs to dump the frame buffer layout etc. > Correction: patches 3 and 5 won't be needed anymore and can be dropped,> it seems. Ack, with the simplificiation the extra patches can be dropped. thanks, -- Joel Fernandes