Re: [patch 6/6] x86: add c1e aware idle function

From: Thomas Gleixner
Date: Fri Jun 13 2008 - 02:03:21 EST


On Thu, 12 Jun 2008, Andrew Morton wrote:
> On Thu, 12 Jun 2008 10:29:00 -0000
> Thomas Gleixner <tglx@xxxxxxxxxxxxx> wrote:
> > + clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &cpu);
> > + default_idle();
> > + local_irq_disable();
> > + clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &cpu);
> > + local_irq_enable();
>
> I worked it out! It took me a while.
>
> This function is called with local irqs disabled.
>
> default_idle() is entered with local irqs disabled but returns with them
> enabled.
>
> clockevents_notify() is supposed to be called with local irqs disabled.
>
> This functions returns with local irqs enabled.

Damn, you decoded my sekrit.

> Was I right? None of any of that is documented anywhere. But it should
> be.

Yeah, needs a big comment. Will add one.

Thanks,

tglx
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