Re: [PATCH 1/2] hung_task: Show the blocker task if the task is hung on mutex

[Waiman Long]

On 2/19/25 9:07 PM, Masami Hiramatsu (Google) wrote:
> On Wed, 19 Feb 2025 18:55:31 -0500
> Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:
>
> > On Thu, 20 Feb 2025 07:56:39 +0900
> > Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx> wrote:
> >
> > > > > > this field, we don't need to take lock, though taking the wait_lock may
> > > > > > still be needed to examine other information inside the mutex.
> > > Do we need to take it just for accessing owner, which is in an atomic?
> > Updating the task_struct would be in the same location as the blocked_on is
> > anyway. I would make it into a wrapper function that is a nop when disabled.
> Should we make it depends on DEBUG_MUTEXES too? I think no. We can introduce
> a different kconfig and wrapper function which calls debug_mutex_*().

No, I don't think so. In fact, the mutex debug code can make use of the 
new fields for additional checking. I believe DEBUG_MUTEXES should 
select the new option.

Cheers,
Longman