Re: [RFC PATCH 2/2] sched: idle: IRQ based next prediction for idle period

[Thomas Gleixner]

On Tue, 12 Jan 2016, Daniel Lezcano wrote:
> On 01/08/2016 04:43 PM, Thomas Gleixner wrote:
> > > +	/*
> > > +	 * Register the setup/free irq callbacks, so new interrupt or
> > > +	 * freed interrupt will update their tracking.
> > > +	 */
> > > +	ret = register_irq_timings(&irqt_ops);
> > > +	if (ret) {
> > > +		pr_err("Failed to register timings ops\n");
> > > +		return ret;
> > > +	}
> > 
> > So that stuff is installed unconditionally. Is it used unconditionally as
> > well?
> 
> Sorry, I am not sure to understand your question. If the kernel is compiled
> with CONFIG_CPU_IDLE_GOV_SCHED=y, this code is enabled and use the irq
> timings. The condition comes from the compilation option.

The question is whether the option also activates that thing or is there still
some /sys/whatever/idlegov magic where you can (de)select it.

Thanks,

	tglx