[PATCH v2 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 and consolidates hung
task warning into a single, atomic log block.

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.

I intend to retain the use of the hung_task_diagnostics() helper function
to consolidate the multi-line logging logic for a detected hung task. The
primary goal is to improve code quality, readability, and ensure diagnostic
output integrity.

Please let me know your thoughts.


Changes since v1 [1]:

 - 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/20251209041218.1583600-1-atomlin@atomlin.com/

Aaron Tomlin (2):
  hung_task: Consolidate hung task warning into an atomic log block
  hung_task: Enable runtime reset of hung_task_detect_count

 Documentation/admin-guide/sysctl/kernel.rst |  2 +-
 kernel/hung_task.c                          | 69 +++++++++++++++++----
 2 files changed, 58 insertions(+), 13 deletions(-)

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2.51.0