Re: [PATCH 09/12] irq: implement IRQ expecting

From: Thomas Gleixner
Date: Thu Jun 17 2010 - 07:16:54 EST



On Thu, 17 Jun 2010, Tejun Heo wrote:

> Hello, Arjan.
>
> On 06/17/2010 05:48 AM, Arjan van de Ven wrote:
> > On Sun, 13 Jun 2010 17:31:35 +0200
> > Tejun Heo <tj@xxxxxxxxxx> wrote:
> >> + */
> >> +void expect_irq(struct irq_expect *exp)
> >
> > I would like to suggest an (optional) argument to this with a duration
> > within which to expect an interrupt....
> >
> > that way in the backend we can plumb this also into the idle handler
> > for C state selection...
>
> Hmmm.... oh, I see. Wouldn't it be much better to use moving avg of
> IRQ durations instead of letting the driver specify it? Drivers are
> most likely to just hard code it and It's never gonna be accurate.

Right, but that's probably more accurate than the core code heuristics
ever will be.

Thanks,

tglx
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/