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From: Pavel Machek <pavel@ucw.cz>
To: Kenneth Chen <kenneth.w.chen@intel.com>
Cc: 'Andrew Morton' <akpm@osdl.org>,
	linux-kernel@vger.kernel.org, linux-ia64@vger.kernel.org
Subject: Re: add lowpower_idle sysctl
Date: Wed, 24 Mar 2004 09:54:22 +0000	[thread overview]
Message-ID: <20040324095422.GA241@elf.ucw.cz> (raw)
In-Reply-To: <200403182159.i2ILxhF12208@unix-os.sc.intel.com>

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?]

  parent reply	other threads:[~2004-03-24  9:54 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2004-03-18  0:31 add lowpower_idle sysctl Kenneth Chen
2004-03-18  1:04 ` Andrew Morton
2004-03-18  3:18 ` Kenneth Chen
2004-03-18  3:28   ` Andrew Morton
2004-03-18  3:40     ` Zwane Mwaikambo
2004-03-18  9:05       ` Dominik Brodowski
2004-03-18 22:59       ` Todd Poynor
2004-03-19  0:09         ` Andrew Morton
2004-03-19  0:43         ` Zwane Mwaikambo
2004-03-18 18:29 ` Kenneth Chen
2004-03-18 21:59 ` Kenneth Chen
2004-03-18 22:35   ` Andrew Morton
2004-03-24  9:54   ` Pavel Machek [this message]
2004-03-23  9:56 ` Pavel Machek
2004-03-25 19:04 ` Chen, Kenneth W
2004-03-25 19:20 ` Chen, Kenneth W

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