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Tue, 18 Aug 2026 00:50:34 +0000 Message-ID: Date: Mon, 17 Aug 2026 17:50:32 -0700 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v10 02/17] x86/resctrl: Require 64-bit x86 for resctrl support To: Tony Luck , Fenghua Yu , "Maciej Wieczor-Retman" , Peter Newman , James Morse , Babu Moger , Drew Fustini , Dave Martin , Chen Yu , David E Box , CC: Christoph Hellwig , , , Hongyu Ning References: <20260729172752.11561-1-tony.luck@intel.com> <20260729172752.11561-3-tony.luck@intel.com> Content-Language: en-US From: Reinette Chatre In-Reply-To: <20260729172752.11561-3-tony.luck@intel.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-ClientProxiedBy: MW4P222CA0020.NAMP222.PROD.OUTLOOK.COM (2603:10b6:303:114::25) To SJ2PR11MB8370.namprd11.prod.outlook.com (2603:10b6:a03:540::20) 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: SJ2PR11MB8370:EE_|SA7PR11MB9544:EE_ X-MS-Office365-Filtering-Correlation-Id: 2bd41469-82a1-46a4-b28f-08defcc2b60b X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|366016|1800799024|7416014|23010399003|921020|18002099003|22082099003|4143699003|11063799006|56012099006|10067099003; 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Future > enhancements like MMIO-based Enhanced RDT (ERDT) monitoring require > readq()/writeq() which are only available on 64-bit. There is also no > realistic use case for users to build a 32-bit kernel on a server and I find the "no realistic use case" statement quite bold. Would a 32-bit kernel not have same needs for resource allocation as a 64-bit kernel? nit: server -> system (since RDT is not limited to servers) > enable resctrl. > > Drop 32-bit support by changing the X86_CPU_RESCTRL dependency from X86 > to X86_64. > > Since X86_CPU_RESCTRL now implies X86_64, remove the redundant X86_64 > dependency from X86_CPU_RESCTRL_INTEL_AET. > > Tested-by: Hongyu Ning > Signed-off-by: Chen Yu > Signed-off-by: Tony Luck > --- I support this change but I would just like to ensure the motivation is accurate. Reinette