Re: [PATCH] hung_task: update DETECT_HUNG_TASK_BLOCKER Kconfig help

[Lance Yang <lance.yang@linux.dev>]

+Cc Petr

get_maintainer.pl is your friend :) please use it next time.

On Thu, Jul 30, 2026 at 11:17:51AM +0800, Xibo Wang wrote:
>The help text still says the feature only covers mutexes, but blocker
>tracking has since been extended to semaphores and rwsems. Update the
>description to match the supported lock types.

Thanks!

>Signed-off-by: Xibo Wang <wangxb12@chinatelecom.cn>
>---
> lib/Kconfig.debug | 9 +++++----
> 1 file changed, 5 insertions(+), 4 deletions(-)
>
>diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
>index 1244dcac2294..c2ffaff918d1 100644
>--- a/lib/Kconfig.debug
>+++ b/lib/Kconfig.debug
>@@ -1320,10 +1320,11 @@ config DETECT_HUNG_TASK_BLOCKER
> 	depends on !PREEMPT_RT
> 	default y
> 	help
>-	  Say Y here to show the blocker task's stacktrace who acquires
>-	  the mutex lock which "hung tasks" are waiting.
>-	  This will add overhead a bit but shows suspicious tasks and
>-	  call trace if it comes from waiting a mutex.
>+	  Say Y here to show the blocker task's stacktrace that holds
>+	  the lock which "hung tasks" are waiting on. Supported lock
>+	  types are mutex, semaphore, and rwsem.
>+	  This will add a bit of overhead but shows suspicious tasks and
>+	  call traces if it comes from waiting on one of these locks.

"holds the lock" seems too strong here...

For semaphores we only have the last holder, and rwsem owner tracking is
best-effort for readers. So this is only a possible blocker, not
necessarily the current lock holder.

I'd rather go with:

	  Say Y here to show a possible blocker task's stacktrace when
	  a hung task is waiting on a mutex, semaphore, or rwsem.
	  This will add a bit of overhead but shows suspicious tasks and
	  call traces for waits on one of these locks.

Cheers, Lance