Re: [PATCH v5 0/3] hung_task: extend blocking task stacktrace dump to semaphore

[Andrew Morton]

On Mon, 14 Apr 2025 22:59:42 +0800 Lance Yang <ioworker0@xxxxxxxxx> wrote:

> Inspired by mutex blocker tracking[1], this patch series extend the
> feature to not only dump the blocker task holding a mutex but also to
> support semaphores. Unlike mutexes, semaphores lack explicit ownership
> tracking, making it challenging to identify the root cause of hangs. To
> address this, we introduce a last_holder field to the semaphore structure,
> which is updated when a task successfully calls down() and cleared during
> up().

Thanks, I'll queue this series in mm.git's mm-nonmm-unstable branch for
some test and exposure.