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Thu, 20 Aug 2026 17:48:47 +0000 Message-ID: Date: Thu, 20 Aug 2026 10:48:45 -0700 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v6 2/9] x86/resctrl: Require 64-bit x86 for resctrl support To: Dave Hansen , "Luck, Tony" , "Chen, Yu C" CC: "tglx@kernel.org" , "bp@alien8.de" , "mingo@redhat.com" , "dave.hansen@linux.intel.com" , "hpa@zytor.com" , "fenghuay@nvidia.com" , "babu.moger@amd.com" , "chen.yu@linux.dev" , "x86@kernel.org" , "linux-kernel@vger.kernel.org" References: <980c4d9c15862de0b0dbc535b646f6b96ea46abe.1784968626.git.yu.c.chen@intel.com> <6c933b5c-620d-4684-b651-48a7ebdfc956@intel.com> <7911abea-d508-4401-b6de-2f6f598f08bf@intel.com> From: Reinette Chatre Content-Language: en-US In-Reply-To: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-ClientProxiedBy: MW4PR03CA0048.namprd03.prod.outlook.com (2603:10b6:303:8e::23) 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_|DM3PPF17031675B:EE_ X-MS-Office365-Filtering-Correlation-Id: 909e75cb-7070-47e4-fece-08defee34981 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|366016|1800799024|23010399003|7416014|376014|56012099006|10067099003|22082099003|18002099003|5023799004|4143699003|11063799006; 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That system showed up in scenarios where servers do not typically venture >>> and per [1] its max memory size (8GB) is significantly less than what servers can support. >> Even with just 8GB you should really use 64-bit. > > Just in practice, 32-bit is very lightly tested. We're generally not > even supporting new CPU features on 32-bit even if the hardware supports > it. Think of shadow stacks, for instance. > > It's actually increasingly hard to even find a modern 32-bit distro. > > So it really has nothing to do with high memory. It just practically > that the arch/x86 32-bit code is increasingly there for legacy reasons. > Its testing goes down every day and the testing of *new* features is for > all intents and purposes zero. > > Honestly, the only people who complain about 32-bit support going away > are folks who "test" it regularly. It's quite rare to see anyone > actually "using" a 32-bit system. I do support this change and clearly stated so in my original review [1]. My comments were only regarding accuracy of the motivation used in the changelog. Reinette [1] https://lore.kernel.org/lkml/d97deaa1-f42c-4fce-8ca8-5ccf8d822cd2@intel.com/