Re: [PATCH] locking/mutex: Redo __mutex_init()

[Waiman Long]

On 11/5/25 2:57 AM, Sebastian Andrzej Siewior wrote:
> On 2025-11-04 11:21:27 [-0500], Waiman Long wrote:
> > > +#ifdef CONFIG_DEBUG_LOCK_ALLOC
> > > +void mutex_init_ld(struct mutex *lock, const char *name, struct lock_class_key *key);
> > > +
> > > +static inline void __mutex_init(struct mutex *lock, const char *name,
> > > +				struct lock_class_key *key)
> > > +{
> > > +	mutex_init_ld(lock, name, key);
> > > +}
> > > +#else
> > > +extern void mutex_init_plain(struct mutex *lock);
> > > +
> > > +static inline void __mutex_init(struct mutex *lock, const char *name,
> > > +				struct lock_class_key *key)
> > > +{
> > > +	mutex_init_plain(lock);
> > > +}
> > > +#endif /* !CONFIG_DEBUG_LOCK_ALLOC */
> > I think it is a good idea to eliminate useless strings in non-lockdep
> > kernel. However, the function names are kind of awkward to me. First of all,
> > it is hard to associate "ld" with lockdep as ld is also the name of the GNU
> > linker. I would prefer to fully spell out as "lockdep". The "_plain" suffix
> > also looks odd to me. How about using the original __mutex_init for the
> > plain version and __mutex_init_lockdep as the lockdep version which calls
> > __mutex_init and use similar naming scheme for the RT versions. What do you
> > think?
> What about
> 	mutex_init_plain() -> mutex_init_generic()
> 	mutex_init_ld() -> mutex_init_lockdep()
Yes, generic is a much better name.
> Using __mutex_init() for the basic/ generic init could work but we have
> already users 13 users (drivers/ mm/ net/) and the rust bindings are
> also attached to it. I would prefer the generic/ lockdep suffix.
>
> If you want __mutex_init() for the generic, regardless, we would first
> need to make room and then something like mutex_init_lockdep() could be
> the public interface replacing __mutex_init() in its current function.

Ah, I don't realize that there are users of __mutex_init() outside of 
the locking subsystem. In this case, we have to maintain the semantics 
of __mutex_init() to avoid affecting other subsystems.

Thanks for the clarification.

Cheers,
Longman