Re: [PATCH] tracing: Annotate ftrace_graph_hash pointer with __rcu

[Steven Rostedt]

On Mon, 3 Feb 2020 11:33:01 -0500
Joel Fernandes <joel@xxxxxxxxxxxxxxxxx> wrote:

> >  	preempt_disable_notrace();
> >  
> > -	if (ftrace_hash_empty(ftrace_graph_hash)) {
> > +	hash = rcu_dereference_protected(ftrace_graph_hash, !preemptible());  
> 
> I think you can use rcu_dereference_sched() here? That way no need to pass
> !preemptible.
> 
> A preempt-disabled section is an RCU "sched flavor" section. Flavors are
> consolidated in the backend, but in the front end the dereference API still
> do have flavors.

Agreed, Amol, can you send an update?

-- Steve