[PATCH v3 0/2] hung_task: Provide runtime reset interface for hung task detector

[Aaron Tomlin <atomlin@atomlin.com>]

Hi Lance, Greg, Petr,

This series introduces the ability to reset
/proc/sys/kernel/hung_task_detect_count.

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(-)

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2.51.0