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To: Eric Anderson <anderson@centtech.com>
From: "Poul-Henning Kamp" <phk@phk.freebsd.dk>
In-Reply-To: Your message of "Mon, 18 Apr 2005 07:08:26 CDT."
             <4263A33A.3030201@centtech.com> 
Date: Mon, 18 Apr 2005 14:19:14 +0200
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cc: freebsd-current@freebsd.org
Subject: Re: powerd(8) 
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In message <4263A33A.3030201@centtech.com>, Eric Anderson writes:
>Lukas Ertl wrote:
>
>There's been some discussion on the -mobile list (I believe) about
>this kind of thing before.  I think powerd is currently running with
>a 'best shot' configuration, and I'm pretty sure that if anyone has 
>a better algorithm in a patch form for people to try, I'm certain the 
>good people with commit bits would easily commit a patched better version.

I don't think a proportional approach will work in this case, the steps
are too far apart.

I also think the switch to full speed is wrong.  Such see-saw
algorithms waste far too much time decaying.  A less steep flank
should be used.

For instance:

	if (idle > 90%)
		reduce clock one step.
	if (idle < 80%)
		increase clock two steps.

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.