Re: [PATCH RFC] tracepoint: Introduce tracepoint callbacks executing with preempt on

From: Steven Rostedt
Date: Fri Apr 27 2018 - 12:46:49 EST

On Fri, 27 Apr 2018 09:45:54 -0700
"Paul E. McKenney" <paulmck@xxxxxxxxxxxxxxxxxx> wrote:

> > > That shouldn't be needed. For the rcu_read_lock_sched case, there is a
> > > preempt_disable which needs to be a notrace, but for the srcu one,
> > > since we don't do that, I think it should be fine.
> >
> > Actually, I think I may agree here too. Because the _notrace is for
> > function tracing, and it shouldn't affect it. If people don't want it
> > traced, they could add those functions to the list in the notrace file.
> OK, feel free to ignore my notrace srcu_read_lock() patch, then. ;-)

Of course I wasn't thinking about the lockdep tracepoints that Joel
mentioned, which happens to be the reason for all this discussion in
the first place :-) Now I think we do need it. (OK, I can keep
changing my mind, can't I?).

-- Steve