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Tue, 16 Dec 2025 03:00:40 +0000 From: Aaron Tomlin To: akpm@linux-foundation.org, lance.yang@linux.dev, mhiramat@kernel.org, gregkh@linuxfoundation.org, pmladek@suse.com Cc: sean@ashe.io, linux-kernel@vger.kernel.org Subject: [PATCH v3 0/2] hung_task: Provide runtime reset interface for hung task detector Date: Mon, 15 Dec 2025 22:00:34 -0500 Message-ID: <20251216030036.1822217-1-atomlin@atomlin.com> X-Mailer: git-send-email 2.51.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-ClientProxiedBy: BN9PR03CA0285.namprd03.prod.outlook.com (2603:10b6:408:f5::20) To CWLP123MB3523.GBRP123.PROD.OUTLOOK.COM (2603:10a6:400:70::10) 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: CWLP123MB3523:EE_|CWXP123MB4183:EE_ X-MS-Office365-Filtering-Correlation-Id: edae1d82-ba68-4f6b-b188-08de3c4f4b85 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|1800799024|366016|376014; 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Writing any value to this file atomically resets the counter of detected hung tasks to zero. This functionality provides system administrators with the means to clear the cumulative diagnostic history following incident resolution, thereby simplifying subsequent monitoring without necessitating a system restart. Please let me know your thoughts. Changes since v2 [1]: - Avoided a needless double update to hung_task_detect_count (Lance Yang) - Restored previous use of pr_err() for each message (Greg KH) - Provided a complete descriptive comment for the helper Changes since v1 [2]: - Removed write-only sysfs attribute (Lance Yang) - Modified procfs hung_task_detect_count instead (Lance Yang) - Introduced a custom proc_handler - Updated documentation (Lance Yang) - Added 'static inline' as a hint to eliminate any function call overhead - Removed clutter through encapsulation [1]: https://lore.kernel.org/lkml/20251211033004.1628875-1-atomlin@atomlin.com/ [2]: https://lore.kernel.org/lkml/20251209041218.1583600-1-atomlin@atomlin.com/ Aaron Tomlin (2): hung_task: Introduce helper for hung task warning hung_task: Enable runtime reset of hung_task_detect_count Documentation/admin-guide/sysctl/kernel.rst | 2 +- kernel/hung_task.c | 66 +++++++++++++++++---- 2 files changed, 55 insertions(+), 13 deletions(-) -- 2.51.0