[Linux-kernel-mentees] [PATCH] tracing: Annotate ftrace_graph_hash pointer with __rcu

Steven Rostedt rostedt at goodmis.org
Wed Feb 5 13:14:09 UTC 2020

On Wed, 5 Feb 2020 05:11:10 -0800
"Paul E. McKenney" <paulmck at kernel.org> wrote:

> I strongly recommend a comment stating why disabling preemption prevents
> ftrace_graph_hash from going away.  I see the synchronize_rcu() after
> the rcu_assign_pointer() in ftrace_graph_release(), but I don't see
> anything that waits on CPUs that RCU is not watching.
> Of course, event tracing -makes- RCU watch when needed, but if that
> was set up, then lockdep would not have complained.
> So what am I missing?

Keep looking in your INBOX and look at the patch I asked you to ack or
complain about ;-) 

-- Steve

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