Zi Li 4efec6c091 samples: enhance hung_task detector test with read-write semaphore support ...

Extend the hung_task detector test module to include read-write semaphore
support alongside existing mutex and semaphore tests.  This module now
creates additional debugfs files under <debugfs>/hung_task, namely
'rw_semaphore_read' and 'rw_semaphore_write', in addition to 'mutex' and
'semaphore'.  Reading these files with multiple processes triggers a
prolonged sleep (256 seconds) while holding the respective lock, enabling
hung_task detector testing for various locking mechanisms.

This change builds on the extensible hung_task_tests module, adding
read-write semaphore functionality to improve test coverage for kernel
locking primitives.  The implementation ensures proper lock handling and
includes checks to prevent redundant data reads.

Usage is:

        > cd /sys/kernel/debug/hung_task
        > cat mutex & cat mutex           # Test mutex blocking
        > cat semaphore & cat semaphore   # Test semaphore blocking
        > cat rw_semaphore_write \
            & cat rw_semaphore_read       # Test rwsem blocking
        > cat rw_semaphore_write \
            & cat rw_semaphore_write      # Test rwsem blocking

Update the Kconfig description to reflect the addition of read-write
semaphore debugfs files.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Zi Li <[email protected]>
Suggested-by: Masami Hiramatsu (Google) <[email protected]>
Cc: Anna Schumaker <[email protected]>
Cc: Boqun Feng <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Joel Granados <[email protected]>
Cc: John Stultz <[email protected]>
Cc: Kent Overstreet <[email protected]>
Cc: Mingzhe Yang <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Sergey Senozhatsky <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Tomasz Figa <[email protected]>
Cc: Waiman Long <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Yongliang Gao <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

2025-07-19 19:08:26 -07:00

..

hung_task_tests.c

samples: enhance hung_task detector test with read-write semaphore support

2025-07-19 19:08:26 -07:00

Makefile

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