Re: [PATCH 1/2] hung_task: replace blocker_mutex with encoded blocker

[Peter Zijlstra <peterz@infradead.org>]

I still fully and totally detest all of this :/

On Wed, Mar 25, 2026 at 09:33:22PM +0800, ruipengqi wrote:

> diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c
> index 555e2b3a665a..61fa97da7989 100644
> --- a/kernel/locking/mutex.c
> +++ b/kernel/locking/mutex.c
> @@ -29,6 +29,7 @@
>  #include <linux/interrupt.h>
>  #include <linux/debug_locks.h>
>  #include <linux/osq_lock.h>
> +#include <linux/hung_task.h>
>  
>  #define CREATE_TRACE_POINTS
>  #include <trace/events/lock.h>
> @@ -191,7 +192,7 @@ __mutex_add_waiter(struct mutex *lock, struct mutex_waiter *waiter,
>  		   struct list_head *list)
>  {
>  #ifdef CONFIG_DETECT_HUNG_TASK_BLOCKER
> -	WRITE_ONCE(current->blocker_mutex, lock);
> +	hung_task_set_blocker(lock, BLOCKER_TYPE_MUTEX);
>  #endif
>  	debug_mutex_add_waiter(lock, waiter, current);
>  
> @@ -209,7 +210,7 @@ __mutex_remove_waiter(struct mutex *lock, struct mutex_waiter *waiter)
>  
>  	debug_mutex_remove_waiter(lock, waiter, current);
>  #ifdef CONFIG_DETECT_HUNG_TASK_BLOCKER
> -	WRITE_ONCE(current->blocker_mutex, NULL);
> +	hung_task_clear_blocker();
>  #endif

Your functions have stubs, you can get rid of those ugly #ifdefs