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Tue, 9 Dec 2025 04:12:22 +0000 From: Aaron Tomlin To: akpm@linux-foundation.org, lance.yang@linux.dev, mhiramat@kernel.org, gregkh@linuxfoundation.org Cc: sean@ashe.io, linux-kernel@vger.kernel.org Subject: [PATCH 0/2] hung_task: Provide runtime reset interface for hung task detector Date: Mon, 8 Dec 2025 23:12:16 -0500 Message-ID: <20251209041218.1583600-1-atomlin@atomlin.com> X-Mailer: git-send-email 2.51.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-ClientProxiedBy: BN9PR03CA0078.namprd03.prod.outlook.com (2603:10b6:408:fc::23) 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_|CWXP123MB6253:EE_ X-MS-Office365-Filtering-Correlation-Id: a5aebad7-61e2-467f-343b-08de36d926d6 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|1800799024|376014|366016; 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The attribute requires writing the value "1" to trigger the reset and returns -EINVAL for any other input, ensuring robustness. This addition is primarily justified by the need for enhanced administrative control and improved diagnostics workflow in a running production environment. It addresses a key limitation of the existing mechanism: the inability to clear persistent state without resorting to a full system reboot. The sysfs interface provides a non-disruptive, runtime method to manage the diagnostic state. After a system administrator investigates a potential hang and corrects the issue, it is now possible to clear the history back to zero. This provides a clean slate for subsequent monitoring, ensuring that any new recurrence of a hung task is immediately reflected by a counter value greater than zero, streamlining the post-mortem diagnostic phase. Aaron Tomlin (2): hung_task: Consolidate hung task warning into an atomic log block hung_task: Provide runtime reset interface for hung task detector .../sysfs-kernel-hung_task_detect_count_reset | 8 +++ kernel/hung_task.c | 68 ++++++++++++++++--- 2 files changed, 66 insertions(+), 10 deletions(-) create mode 100644 Documentation/ABI/testing/sysfs-kernel-hung_task_detect_count_reset -- 2.51.0