Re: [PATCH 11/12] locking/mutex: Revive fast functions for CONFIG_LOCK_TRACEPOINTS

Namhyung Kim
2022-02-09T20:15:38Z

Hi Peter,

On Wed, Feb 9, 2022 at 12:41 AM Peter Zijlstra <peterz@infradead.org> wrote:
>
> On Tue, Feb 08, 2022 at 10:42:07AM -0800, Namhyung Kim wrote:
> > I'm not entirely sure why it removed the fast versions when lockdep is
> > on. It seems easy to add the required annotation when the fast
> > version is succeeded as far as the tracpoints are concerned.
>
> IIRC it was something like, lockdep depends on MUTEX_DEBUG and that in
> turn relied on not having the fast path enabled. MUTEX_DEBUG used to
> always take the wait_lock to ensure the debug state is consistent with
> the lock state.

I see. Thanks for the explanation!

Namhyung