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Thu, 24 Sep 2026 20:49:31 +0000 Message-ID: Date: Thu, 24 Sep 2026 13:49:29 -0700 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v12 18/25] x86/resctrl: Use registered function pointers for AET enumeration 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 , , References: <20260916231320.14502-1-tony.luck@intel.com> <20260916231320.14502-19-tony.luck@intel.com> From: Reinette Chatre Content-Language: en-US In-Reply-To: <20260916231320.14502-19-tony.luck@intel.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-ClientProxiedBy: MW4PR04CA0166.namprd04.prod.outlook.com (2603:10b6:303:85::21) 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_|CY8PR11MB6820:EE_ X-MS-Office365-Filtering-Correlation-Id: 3ff8f1fc-51d3-4422-9916-08df1a7d5502 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|1800799024|7416014|376014|23010399003|366016|921020|6133799003|10067099003|22082099003|56012099006|4143699003|11063799006|18002099003|5023799004; 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This creates expectation that there are no direct function calls remaining after this patch, but there are. This is part of the asymmetric concern raised in previous two versions of this patch. > > In preparation for enumeration on each mount of the resctrl file system > place a hold on the pmt_telemetry module while enumerating AET events during > pre-mount processing. Release the hold if no events were enabled. This hold > will be released when the per-mount code is added. You added that this hold will be released in later code. Why? Could you please add why it is safe to take a hold without releasing it? Why does this have to be done asymmetrically? This patch is difficult to reason about since it claims to protect calls to the module yet it does not remove all the direct calls that continue to be made without any protection. Even the calls it does claim to protect takes a hold without releasing it without any indication why it is safe to do so. At this point this looks like a patch that breaks the driver. > > Signed-off-by: Tony Luck Reinette