Re: [PATCH] cpuidle: avoid singing capacitors

From: Pavel Machek
Date: Mon Mar 03 2008 - 15:45:46 EST


Hi!

> I've been playing around with this for a bit, and the jiffies approach
> just had too many gotchas. So I tried using the information that was
> already present in the menu governor. This is what I came up with.
>
> It solves the primary problem of getting rid of the noise. I've also
> tried some crude power measurements and I couldn't get any difference
> with and without the patch. Powertop also nicely shows that the CPU is
> still spending almost all of its time in C3. Therefore, I'm letting the
> effects of it be enabled by default.
>
> So I'm taking the [RFC] off it. Please still test and see that it
> solves the issue on other machines, and the it does not cause any big
> power surges.
>
> diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c
> index 78d77c5..d9c43e3 100644
> --- a/drivers/cpuidle/governors/menu.c
> +++ b/drivers/cpuidle/governors/menu.c
> @@ -16,6 +16,8 @@
>
> #define BREAK_FUZZ 4 /* 4 us */
>
> +static unsigned int min_deep_sleep = 2000;
> +

Well, why not, but I believe we should default to old behaviour... not
all machines are cheaply-build.
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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