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Thu, 8 Oct 2026 07:27:44 +0000 Date: Thu, 8 Oct 2026 15:14:40 +0800 From: Chen Yu To: Reinette Chatre CC: , , , , , , , , , , , , , , Subject: Re: [PATCH v2 2/5] x86,fs/resctrl: Remove unnecessary non-linear MBA configuration check Message-ID: References: <54ee80a047388ed372f1e848eccbac930a9745be.1791406459.git.reinette.chatre@intel.com> Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <54ee80a047388ed372f1e848eccbac930a9745be.1791406459.git.reinette.chatre@intel.com> X-ClientProxiedBy: TP0P295CA0028.TWNP295.PROD.OUTLOOK.COM (2603:1096:910:5::8) To DM4PR11MB6020.namprd11.prod.outlook.com (2603:10b6:8:61::19) 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: DM4PR11MB6020:EE_|IA4PR11MB9277:EE_ X-MS-Office365-Filtering-Correlation-Id: f7c7cee3-9eef-4646-0129-08df250da518 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|7416014|376014|23010399003|1800799024|366016|6133799003|18002099003|22082099003|4143699003|5023799004|10067099003|11063799006|56012099006; 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Intel indicates this for MBA while AMD and MPAM do not. > > This check can never fail. No Intel SKU supports non-linear delay values, > and the placeholder for such support, rdt_get_mb_table(), is only called > during enumeration and always fails. A non-linear Intel MBA resource is > thus never marked as capable of allocation, and resctrl never exposes it > to user space or attempts to configure it. Every Intel MBA resource capable > of allocation has linear delay values, and AMD and MPAM never indicate a > need for them. > > Fail enumeration of a non-linear Intel MBA resource directly to make clear > that it is not supported, and remove the check together with the > resctrl_membw::arch_needs_linear property it relies on. > > Keep the informational message printed when such a system is encountered. > While moving it, reword it to no longer refer to the removed mapping table, > add the missing newline, and label the printed family value "family" instead > of "cpu". > > Signed-off-by: Reinette Chatre > Reviewed-by: Chen Yu thanks, Chenyu