Re: add lowpower_idle sysctl

[Pavel Machek]

Hi!

> Sounds good, Thanks for the suggestion. I just coded it up:
> 
> 
> diff -Nur linux-2.6.4/include/linux/cpu.h linux-2.6.4.halt/include/linux/cpu.h
> --- linux-2.6.4/include/linux/cpu.h	2004-03-10 18:55:23.000000000 -0800
> +++ linux-2.6.4.halt/include/linux/cpu.h	2004-03-18 13:47:43.000000000 -0800
> @@ -52,6 +52,12 @@
> 
>  #endif /* CONFIG_SMP */
>  extern struct sysdev_class cpu_sysdev_class;
> +extern int idle_mode;
> +
> +#define IDLE_NOOP	0
> +#define IDLE_HALT	1
> +#define IDLE_POLL	2
> +#define IDLE_ACPI	3
> 

How is idle_noop different from idle_poll?

idle_halt is equivalent to idle_acpi_C1. But acpi supports also C2
(deeper sleep), and C3 (sleep without coherent caches) and newer
machines support even more. You might want to talk to Len Brown.

[And yes, limiting to C2 (for example) *is* usefull; some machines
(nforce2 iirc) have bugs, and die if you do C3 at wrong time].

								Pavel
-- 
When do you have a heart between your knees?
[Johanka's followup: and *two* hearts?]
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