hung_task: add docs for hung_task_detect_count

This commit introduces documentation for hung_task_detect_count in
kernel.rst.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Mingzhe Yang <[email protected]>
Signed-off-by: Lance Yang <[email protected]>
Cc: Bang Li <[email protected]>
Cc: Baolin Wang <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: Huang Cun <[email protected]>
Cc: Joel Granados <[email protected]>
Cc: Joel Granados <[email protected]>
Cc: John Siddle <[email protected]>
Cc: Kent Overstreet <[email protected]>
Cc: Ryan Roberts <[email protected]>
Cc: Thomas Weißschuh <[email protected]>
Cc: Yongliang Gao <[email protected]>
Cc: Zi Yan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

Author: ioworker0

Documentation/admin-guide/sysctl/kernel.rst

@@ -401,6 +401,15 @@ The upper bound on the number of tasks that are checked.
 This file shows up if ``CONFIG_DETECT_HUNG_TASK`` is enabled.
 
 
+hung_task_detect_count
+======================
+
+Indicates the total number of tasks that have been detected as hung since
+the system boot.
+
+This file shows up if ``CONFIG_DETECT_HUNG_TASK`` is enabled.
+
+
 hung_task_timeout_secs
 ======================