Re: [tip: core/rcu] rcu/tree: Mark the idle relevant functions noinstr

[Peter Zijlstra <peterz@xxxxxxxxxxxxx>]

On Tue, May 19, 2020 at 07:52:33PM -0000, tip-bot2 for Thomas Gleixner wrote:
> @@ -979,7 +988,7 @@ static void rcu_disable_urgency_upon_qs(struct rcu_data *rdp)
>   * if the current CPU is not in its idle loop or is in an interrupt or
>   * NMI handler, return true.
>   */
> -bool notrace rcu_is_watching(void)
> +bool rcu_is_watching(void)
>  {
>  	bool ret;
>  

This ^..

it is required because __ftrace_ops_list_func() /
ftrace_ops_assist_func() call it outside of ftrace recursion, but only
when FL_RCU, and perf happens to be the only user of that.

another morning wasted... :/