Re: [PATCH RFC v5 3/6] srcu: Add notrace variant of srcu_dereference

From: Paul E. McKenney
Date: Tue May 01 2018 - 11:26:35 EST


On Tue, May 01, 2018 at 11:04:03AM -0400, Steven Rostedt wrote:
> On Tue, 1 May 2018 07:18:17 -0700
> "Paul E. McKenney" <paulmck@xxxxxxxxxxxxxxxxxx> wrote:
>
>
> > > diff --git a/include/linux/srcu.h b/include/linux/srcu.h
> > > index 2ec618979b20..a1c4947be877 100644
> > > --- a/include/linux/srcu.h
> > > +++ b/include/linux/srcu.h
> > > @@ -135,6 +135,11 @@ static inline int srcu_read_lock_held(const struct srcu_struct *sp)
> > > */
> > > #define srcu_dereference(p, sp) srcu_dereference_check((p), (sp), 0)
> > >
> > > +/**
> > > + * srcu_dereference_notrace - no tracing and no lockdep calls from here
> > > + */
> > > +#define srcu_dereference_notrace(p, sp) srcu_dereference_check((p), (sp), 1)
> >
> > Given that this is a one-liner, why not just use srcu_dereference_check()
> > directly, with 1 as you do above to disable lockdep?
>
> I prefer what Joel did. It documents why we are doing this. Open coding
> the call directly will just confuse others that touch tracepoint code.

I suppose...

Reviewed-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>