Re: [PATCH RFC 2/3] locking/percpu-rwsem: Extract __percpu_up_read_slowpath()

[Peter Zijlstra]

On Thu, Mar 05, 2026 at 10:47:03AM -0500, Steven Rostedt wrote:
> On Wed, 4 Mar 2026 23:02:23 +0100
> Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
> 
> > > diff --git a/include/linux/percpu-rwsem.h b/include/linux/percpu-rwsem.h
> > > index c8cb010d655e..89506895365c 100644
> > > --- a/include/linux/percpu-rwsem.h
> > > +++ b/include/linux/percpu-rwsem.h
> > > @@ -107,6 +107,8 @@ static inline bool percpu_down_read_trylock(struct percpu_rw_semaphore *sem)
> > >  	return ret;
> > >  }
> > >  
> > > +void __percpu_up_read_slowpath(struct percpu_rw_semaphore *sem);
> > > +  
> > 
> > extern for consistency with all the other declarations in this header.
> 
> I wonder if a cleanup patch should be added to remove the "extern" from the
> other functions, as that tends to be the way things are going (hch just
> recommended it elsewhere).

Well, I rather like the extern. But yeah, I know hch does not agree.

> > 
> > s/_slowpath//, the corresponding down function also doesn't have
> > _slowpath on.
> > 
> > >  static inline void percpu_up_read(struct percpu_rw_semaphore *sem)
> > >  {
> > >  	rwsem_release(&sem->dep_map, _RET_IP_);  
> 
> And since "slowpath" is more descriptive (and used in the rtmutex code),
> should that be added too?

It already has __ prefix, no point in making the name even longer for no
real benefit.