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Thu, 10 Jul 2025 08:30:04 +0000 Message-ID: <99573578-95e8-4b97-b2c8-d8229e4816e5@intel.com> Date: Thu, 10 Jul 2025 16:29:51 +0800 User-Agent: Mozilla Thunderbird Subject: Re: [tip:sched/core] [sched/smp] 06ddd17521: BUG:using_smp_processor_id()in_preemptible To: Sebastian Andrzej Siewior CC: kernel test robot , Ingo Molnar , , , , , Peter Zijlstra , Dietmar Eggemann , Juri Lelli , "Linus Torvalds" , Mel Gorman , Shrikanth Hegde , Steven Rostedt , Valentin Schneider , "Vincent Guittot" , References: <202507100448.6b88d6f1-lkp@intel.com> <6cf071f3-ff5b-4025-8ce7-2f2cceb03984@intel.com> <20250710062528.T-Obm39T@linutronix.de> <292e70ed-aae5-4f52-8f85-80cba7ff301d@intel.com> <20250710081114.5wnABNG7@linutronix.de> Content-Language: en-US From: "Chen, Yu C" In-Reply-To: <20250710081114.5wnABNG7@linutronix.de> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit X-ClientProxiedBy: SI1PR02CA0043.apcprd02.prod.outlook.com (2603:1096:4:1f6::19) 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_|SA1PR11MB6565:EE_ X-MS-Office365-Filtering-Correlation-Id: cf7ada58-18b4-4a6f-cc53-08ddbf8bf82d X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|376014|1800799024|7416014|366016; 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The scope of guard(preempt)() in migrate_disable() is just >> within the migrate_disable(). debug_smp_processor_id() warns when the >> preemption is enabled. > > does migrate_disable() really have no effect on > debug_smp_processor_id()? > I see. So there is still a CONFIG_SMP to check migrate_disbled in debug_smp_processor_id(), and that was skipped if we do not have CONFIG_SMP set. thanks, Chenyu>> Thanks, >> Chenyu > Sebastian