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From: =?utf-8?Q?Dag-Erling_Sm=C3=B8rgrav?= <des@des.no>
To: "Daniel O'Connor" <doconnor@gsoft.com.au>
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Date: Thu, 17 Jan 2008 11:15:02 +0100
In-Reply-To: <200801171115.43663.doconnor@gsoft.com.au> (Daniel O'Connor's
	message of "Thu\, 17 Jan 2008 11\:15\:35 +1030")
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Cc: njl@freebsd.org, bruno@freebsd.org,
	Stefan Lambrev <stefan.lambrev@moneybookers.com>,
	freebsd-current@freebsd.org, Igor Mozolevsky <igor@hybrid-lab.co.uk>,
	Maxim Sobolev <sobomax@digifonica.com>
Subject: Re: powerd adaptive mode latching
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"Daniel O'Connor" <doconnor@gsoft.com.au> writes:
> One problem with it is that it lags behind actual usage by a few
> seconds (presumably averaging it).

It is based on the (didle/dt) / (dtotal/dt) fraction computed from
kern.cp_time, which can take a while to ramp up.  This is not easily
seen in a cursory reading of the code, as the fraction is computed in a
very roundabout way.

> Turning the LCD off saves about 4W too.

Hmm, it would be interesting to experiment with varying backlight
brightness based on system load :)

DES
--=20
Dag-Erling Sm=C3=B8rgrav - des@des.no