From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from BN8PR05CU002.outbound.protection.outlook.com (mail-eastus2azon11011020.outbound.protection.outlook.com [52.101.57.20]) (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 B6BAF374A08 for ; Fri, 7 Aug 2026 17:57:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=52.101.57.20 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786125444; cv=fail; b=a60SMRYb67wX/Z3lUuBoC11jn1gSVCoZJY4ted84xIQs8fYNE+kRvu0vpiLaM4KJ6UT9gk+N0BDQAjRKcUqhizZpH4ZFg3MZ513USl8DGd3K4YKHsnuaAtWFcNWFdBGA6wZul5OYw/XTg12mIfv+r/aB2bkRo2r5jjJaA+na7E8= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786125444; c=relaxed/simple; bh=tiOSPF+3DQWjb9+/IH92FftcFlsWvh3MQ/e/IVCAbqM=; h=Message-ID:Date:Subject:To:Cc:References:From:In-Reply-To: Content-Type:MIME-Version; b=rJ3Einspc1OVDCBXY5LOKaAT+ty9jacIXibHoUzKcn0Hg8A2wjnBTshIShgHMw3Cc5av9aTUD5dL/48akqHDQoaDLAHpRNqajZHimlTTjZ8pyjm4wK+wCXdN+XgW/CXRq1IvBfhXLIqUFYLoZEFdwPe34NkVOMrQazontg2yvSs= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amd.com; spf=fail smtp.mailfrom=amd.com; dkim=pass (1024-bit key) header.d=amd.com header.i=@amd.com header.b=ToIpvmDM; arc=fail smtp.client-ip=52.101.57.20 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amd.com Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=amd.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=amd.com header.i=@amd.com header.b="ToIpvmDM" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=w6rB5NApK57K/p+yr0iAxJ38n7hbog3sQQj70c0Ow+PbOGth6DTCnu2PV7TCAFbPp3elP74bwMNrXuIUKqCrj9coD3FxwCLwC9HaWNnAdTN5frtm6iaw2Hsjf7vQoFIdu9gLMExtYWcsQrM1KMxSLXq2Kcgsaiz8Czt6iK35S+Vqkhoyoat41cHRUFDtKMq98BWW1O9fmLzKLrqUSlkgdjppkBXsx525YsvThkkLPvthUWZSqJXj6saao4GAPUHbB2OhcRQ/L5VjIC4ryP0V3vRIOwubhKnrNsv7sj3k3nIrHG8v/KKOKKI6pTEfV1qeps/KKUZpvKoFhvV9Prz6PQ== 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=IXCIOa/mpL8mE5EZ7ONQWCKo+Gi6s4Suju7Fm4xwGbo=; b=tRJRLGVUNWIIMbt25XQtHF8p3TvzeQGaHNZNtlbFvU6f6KdcymPGeRCiANtPVAv4PuYs+P6w8Qntk4YyRggjjlY62UIPcxWh/WFZcTx5btT66aNhKO5Jvdtpa+sLYNwvgwAsundXMJ9Zj7SKqarF9Dvy/NcatvpXTM8NDLxatUBjV+PQh0gDQj5beGUPU68ljt6/Y/mtT3mFW1eK4WradQMRQQCMxOzs6vBUV+b/+GjZejCwZHsbok/PHPZIGbiv2+SUpAxzMLwrlMCwvEPapnRaZc7ED4kVVnEoGF6H1WjBmsH4jG1TGyi7zFIhNGGSfBcHWtRE3GANhE+6TgnIKw== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=amd.com; dmarc=pass action=none header.from=amd.com; dkim=pass header.d=amd.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amd.com; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=IXCIOa/mpL8mE5EZ7ONQWCKo+Gi6s4Suju7Fm4xwGbo=; b=ToIpvmDMoTeIkhuvg2yZVzgIhkJsxbYzSrjLVvvEkR0KE9KHkPhJYq5J6RtRcOGaAAgcPd8g1NlIFd7irpTlYDemTo9ksVXdo5r1DAV38v9cqZojGV3NG7EwtnjlcNYKsGP56a+qxjtBM7E7GsbpPgPN4ASveu/vRut+hV8Rbck= Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=amd.com; Received: from BL1PR12MB5320.namprd12.prod.outlook.com (2603:10b6:208:314::17) by CH1PR12MB9695.namprd12.prod.outlook.com (2603:10b6:610:2af::10) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.21.292.23; Fri, 7 Aug 2026 17:57:18 +0000 Received: from BL1PR12MB5320.namprd12.prod.outlook.com ([fe80::1876:4a6d:2cf5:b8d1]) by BL1PR12MB5320.namprd12.prod.outlook.com ([fe80::1876:4a6d:2cf5:b8d1%5]) with mapi id 15.21.0292.022; Fri, 7 Aug 2026 17:57:18 +0000 Message-ID: <5c4efba0-2cda-4290-bf01-30d2eb2ae0ee@amd.com> Date: Fri, 7 Aug 2026 12:57:15 -0500 User-Agent: Mozilla Thunderbird Subject: Re: [RFC v2] arm,x86,fs/resctrl: Generic schema description Proof of Concept To: "Chen, Yu C" Cc: Ben Horgan , James Morse , Dave Martin , Babu Moger , Drew Fustini , Fenghua Yu , Borislav Petkov , Thomas Gleixner , Dave Hansen , Peter Newman , "x86@kernel.org" , "linux-kernel@vger.kernel.org" , Reinette Chatre , "Luck, Tony" , "chen.yu@linux.dev" References: <7a8b6cc8-d194-4af2-9fb9-2438d2dcae01@intel.com> <9d0239e6-318e-4a59-937d-a64b839e02e9@intel.com> Content-Language: en-US From: "Moger, Babu" In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-ClientProxiedBy: CH0PR03CA0253.namprd03.prod.outlook.com (2603:10b6:610:e5::18) To BL1PR12MB5320.namprd12.prod.outlook.com (2603:10b6:208:314::17) 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: BL1PR12MB5320:EE_|CH1PR12MB9695:EE_ X-MS-Office365-Filtering-Correlation-Id: 6fa49f88-ab98-47f2-b096-08def4ad51ff X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|1800799024|366016|376014|7416014|23010399003|18002099003|22082099003|10067099003|56012099006|4143699003|6133799003|11063799006; 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:BL1PR12MB5320.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(1800799024)(366016)(376014)(7416014)(23010399003)(18002099003)(22082099003)(10067099003)(56012099006)(4143699003)(6133799003)(11063799006);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?bjc4NnhkOW1WWXQ3R3lybjltMGpkMjFISVYwMisyc3U2MGZab2ZQcHZUSjRH?= =?utf-8?B?UnlsanhsckYyRThtVjA5dFZXT3VCai9icGVxZW1IUzQ0VzBhSjhzMlRjblor?= =?utf-8?B?cEJXb21sTXI0cEpETGhaTzVyZ2RxYWxSTlFGUmpDN09FWVNGSkprL2w5UFBs?= =?utf-8?B?WnZaVU1BT09ObzBFMU1kRno1UU96ekp2VG43OGQrUVpzdjRibk1FKzR0bzNt?= =?utf-8?B?S1VKaGY0MXhwZnVYckFkamVKTGFWZTd2dWp3cTd0MVlWem1qMHpyM29SMCtz?= =?utf-8?B?NGVSVHVBVXVhWHdMUHNwcE1oY1NnVXF1SDZiMDFXZWtNYzVxVkFabHB2TVRy?= =?utf-8?B?SWNBcXlKK3RNSWJha3NxMGlpbU9yaFExSG5qaDJlZ05NdnVMdEJHL0pTcHNI?= =?utf-8?B?WDlmL28vZEZ1N1VzUmIwaFl4a1JrRzQ4YWF4dHFLQ2ZnbzVEZUR0MmpTd1VH?= =?utf-8?B?OUF3L0w0L2xYSkxTOFBQWERybWNMUjhpOU83SlE5OXozWDdCQ0dGbUU0WVlJ?= =?utf-8?B?bW80VTFaSGZ5UGFpWURjbGRaU1JHS2pGd09NVkk0cVJRZVgwRUdkWmJYMk1J?= =?utf-8?B?Zk9pNjhpZ1hIZklETy9GZGErM1p5UEJPSk1iQzJ6QmFBenREcE56S2JpZTUr?= =?utf-8?B?Wlgvb2RRZFlwalQ0RXZGK1hqSHI1c2hUQWZqRldPWnE1dTUxYkJoUHgrWFRw?= =?utf-8?B?eUlZRk0xQ2ZCK0JZRGNxQW5hUUJlY1RCOUhZc1NNRGV4N05TS1BJd1Awc3dJ?= =?utf-8?B?emg4ZHN1RnNRTS9VL3cwVHoxWFVkcEVvcXB1dW5aRUhkOXNvWGhpODNaVzdn?= =?utf-8?B?WjA2U1dSV3A1c2ttelg5MW9vZDZINUxCbG5zSGtSNlRRcjFXdTB4Yitzb2E2?= =?utf-8?B?RmhlTHdJTW1mbkdPYWJxenRvWldHR3l4NFJENW5nZFhMVnZGcmFRN0pqWjMx?= =?utf-8?B?K05qMEJUL0Y1UXoxWlBVanYzdU1OZ1FpOG1UOXFRR3BZeDVzR3lIODdzYmh0?= =?utf-8?B?bys0ZkR2dG9tcXY0Y3dRRlpkMlhjdGw2dzV2SEp5WHl3RU5lSGJOWmFQdGdn?= =?utf-8?B?dy9mVHIzWUp3VGhVMlg2K0NUd3NjYlRCTWlGMVRtNEd1eExtZzhWNDlVdktR?= =?utf-8?B?TjJLR1FYbDNoaCtHaW5Bd0ZLdWRxWWFoV3RlMjFYRzhrdHVyZjYzZDEvaEJE?= =?utf-8?B?S1oydlY2T1ZweXlweUVZTTV2NzhvU2ovU09BL0prSFg4M21OTXJjamo5eVZR?= =?utf-8?B?Y3Q4WGhUV1ZCVUhDUkJjUXJ0Q0d5VVEwVVJKZ0hUYi9idkhrTkx1elVlRkoy?= =?utf-8?B?ODFpWGtnL3VCN01jUjV2TzRIMlhQMitqeFp2TmUybmtCNngxS0x4Yjdaa1Bv?= =?utf-8?B?dko0dGlydmhHVTBoTlB6d2M4VlhUR0k5WWMyam1TQWE2eExjQzRtRzZSWjIy?= =?utf-8?B?Vk8zbVlnZ3o3RHlWRzEvK3dvYmxIa0k1ZjBxL3JRWitOamVDcktEZHpkQ09B?= =?utf-8?B?TEprMGZHSDY0bi9kZnFoZEI4WGJYSXhzZlVMR3VFb2pYS0tkWmhjRTl6UFlV?= =?utf-8?B?THh2UXZXcGtLN0h4Ym1FWjE3SWxJVlFnRDhwNXVzT3lwaXYrRUEwL0c4OVRP?= =?utf-8?B?cGV2RkwzNFR0ZnBqV0pIeTBnc0FZWlVmTHdrdUF0TUxMZXJXWm82WnVER0h5?= =?utf-8?B?SVVoZHM1bDEzaE84WEgveTRBRml4aUtpR1VCdTlDcCt0TDhkaVUwOUFzc0lj?= =?utf-8?B?NHJEQVYxL2p6Qllvd1MwcnBjYUVPd2RmcFlib0xPeTlKMk91TFFPQWZYT21I?= =?utf-8?B?MXE5cGFsblRvVG9meDBKckptaUQwM1lkZ09sZG5XZktrUGkzYS9tOVBiVTBp?= =?utf-8?B?ZWpEbXh2a21NaEJnWjlUSXBQSjZObE9BM2NUODVlYjU5MXI0MndXUlJDOThw?= =?utf-8?B?UWhpMS9KVEV0UDU4NmlkOGQ2NzZaYkZpNnJHaHJJNUYvT2IwZ21ySnU2OXd0?= =?utf-8?B?K3JncForVkVFd3M3cHJKb1AvbXZUbDJYVElQV3NkMm1FZk9MNHFUbTRsVFl1?= =?utf-8?B?MEUzRm11bndhbnVUdnJLOE1Oc3hTckVtdzBzbUNiUXNDMW1iNlk4MjgxTlU3?= =?utf-8?B?SUlsUi9EcGZ2b3lScGM4RUpuQlFSb2FQRjBEYXZsSzFMbHk0SDFMcndxS0kr?= =?utf-8?B?THJpTU1wK3l1NTlVWUFRd01oanJ5SElOZzhGcUhhc0pSbDNIOTZWR2NzVjlk?= =?utf-8?B?SkM1QzlCandrK0RySWxZdzdJUjExMXNVQ1RDRndtUE41VDZmaC9rWVFCOFV4?= =?utf-8?Q?ZDseRSQzyd9hNNSC4F?= X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-Network-Message-Id: 6fa49f88-ab98-47f2-b096-08def4ad51ff X-MS-Exchange-CrossTenant-AuthSource: BL1PR12MB5320.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 07 Aug 2026 17:57:18.0018 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: VEWD26PvOKq/4beh3JFT7PnoZOYc/ZsQYqLSUDHmzNKVpfq4vuAwuVtjMvRrRpUQ X-MS-Exchange-Transport-CrossTenantHeadersStamped: CH1PR12MB9695 Hi Chenyu, On 8/7/2026 10:35 AM, Chen, Yu C wrote: > Hi Babu, > > On 8/7/2026 10:14 PM, Moger, Babu wrote: > > [ ... ] > >>>> Is same needed for x86? I don't see any initialization of the >>>> "r_ctrl.emulated_by" lists in similar initialization functions. >>> x86 "emulated_by" list initialization should be in both branches. >>> >>> Branch resctrl/controls_rfc_v2.1 combined all "emulated_by" list >>> initialization >>> (for x86 and MPAM) into commit: >>> 3407e523c988 ("fs/resctrl: Introduce emulated controls and control >>> mode") >>> >>> In the original resctrl/controls_rfc_v2 the x86 "emulated_by" list >>> initialization can >>> be found in commit fbed64f80515 ("x86/resctrl: SAMPLE: Emulated >>> controls") >>> >> >> Looking at the commit: >> >> commit 3407e523c988 ("fs/resctrl: Introduce emulated controls and >> control mode") >> >> Based on the patch description, emulated controls are intended to be >> used only when there is a difference between the native and legacy >> controls. If no such difference exists, both modes should operate >> identically. >> >> For MBA(AMD) and GMBA, there does not appear to be any difference >> between the two modes. Is that understanding correct? >> > > Yes I think so. __rdt_get_mem_config_amd() does > INIT_LIST_HEAD(&hw_ctrl->r_ctrl.emulated_by), so the list is > a valid empty one and resctrl_enabled_ctrl_iter_next() short-circuits > on list_empty() regardless of ctrl_mode, meaning MBA > expose the same single control in either mode. > Got it, Thank you Babu