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

From	Thomas Gleixner <tglx@linutronix.de>
Newsgroups	linux.kernel
Subject	Re: [RFC PATCH 2/2] sched: idle: IRQ based next prediction for idle period
Date	2016-01-12 15:30 +0100
Message-ID	<qQ87p-28L-21@gated-at.bofh.it> (permalink)
References	(1 earlier) <qNYc9-2Y2-5@gated-at.bofh.it> <qOHsB-gc-7@gated-at.bofh.it> <qQ6yD-WB-33@gated-at.bofh.it> <qQ7uH-1zT-21@gated-at.bofh.it> <qQ7XK-23e-49@gated-at.bofh.it>
Organization	linux.* mail to news gateway

Show all headers | View raw

On Tue, 12 Jan 2016, Daniel Lezcano wrote:
> On 01/12/2016 02:42 PM, Thomas Gleixner wrote:
> > 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.
> 
> Yes, in the next patches of the series I did not send, we can switch to the
> cpuidle's governor framework or idle-sched. I will look at how to disable it
> when switching to the cpuidle's governors.

You better implement the switching part in the cpuidle core first, i.e. proper
callbacks when a governor is switched in/out. Then make use of this switcheroo
right away. Doing it the other way round is just wrong.

Thanks,

	tglx

Thread

[RFC PATCH 2/2] sched: idle: IRQ based next prediction for idle period Daniel Lezcano <daniel.lezcano@linaro.org> - 2016-01-06 16:30 +0100
  Re: [RFC PATCH 2/2] sched: idle: IRQ based next prediction for idle  period Nicolas Pitre <nicolas.pitre@linaro.org> - 2016-01-06 18:50 +0100
    Re: [RFC PATCH 2/2] sched: idle: IRQ based next prediction for idle  period Daniel Lezcano <daniel.lezcano@linaro.org> - 2016-01-07 16:50 +0100
      Re: [RFC PATCH 2/2] sched: idle: IRQ based next prediction for idle  period Nicolas Pitre <nicolas.pitre@linaro.org> - 2016-01-12 20:30 +0100
    Re: [RFC PATCH 2/2] sched: idle: IRQ based next prediction for idle  period Daniel Lezcano <daniel.lezcano@linaro.org> - 2016-01-10 23:40 +0100
      Re: [RFC PATCH 2/2] sched: idle: IRQ based next prediction for idle  period Nicolas Pitre <nicolas.pitre@linaro.org> - 2016-01-10 23:50 +0100
        Re: [RFC PATCH 2/2] sched: idle: IRQ based next prediction for idle  period Daniel Lezcano <daniel.lezcano@linaro.org> - 2016-01-11 00:00 +0100
          Re: [RFC PATCH 2/2] sched: idle: IRQ based next prediction for idle  period Nicolas Pitre <nicolas.pitre@linaro.org> - 2016-01-11 00:20 +0100
  Re: [RFC PATCH 2/2] sched: idle: IRQ based next prediction for idle  period Thomas Gleixner <tglx@linutronix.de> - 2016-01-08 16:50 +0100
    Re: [RFC PATCH 2/2] sched: idle: IRQ based next prediction for idle  period Daniel Lezcano <daniel.lezcano@linaro.org> - 2016-01-12 13:50 +0100
      Re: [RFC PATCH 2/2] sched: idle: IRQ based next prediction for idle  period Thomas Gleixner <tglx@linutronix.de> - 2016-01-12 14:50 +0100
        Re: [RFC PATCH 2/2] sched: idle: IRQ based next prediction for idle  period Daniel Lezcano <daniel.lezcano@linaro.org> - 2016-01-12 15:20 +0100
          Re: [RFC PATCH 2/2] sched: idle: IRQ based next prediction for idle  period Thomas Gleixner <tglx@linutronix.de> - 2016-01-12 15:30 +0100
            Re: [RFC PATCH 2/2] sched: idle: IRQ based next prediction for idle  period Daniel Lezcano <daniel.lezcano@linaro.org> - 2016-01-12 16:00 +0100
              Re: [RFC PATCH 2/2] sched: idle: IRQ based next prediction for idle  period Thomas Gleixner <tglx@linutronix.de> - 2016-01-12 16:20 +0100
                Re: [RFC PATCH 2/2] sched: idle: IRQ based next prediction for idle  period Daniel Lezcano <daniel.lezcano@linaro.org> - 2016-01-12 17:10 +0100
                Re: [RFC PATCH 2/2] sched: idle: IRQ based next prediction for idle  period Thomas Gleixner <tglx@linutronix.de> - 2016-01-13 10:20 +0100

csiph-web