powerd adaptive mode latching

Stefan Lambrev stefan.lambrev at moneybookers.com
Fri Jan 11 04:57:54 PST 2008


Dag-Erling Smørgrav wrote:
> Stefan Lambrev <stefan.lambrev at moneybookers.com> writes:
>> While still here any idea how to make powerd to not lower cpufreq
>> under let's say 1000HZ?  I want to manually set the allowed minimum,
>> because my laptop is lagging too much under certain speeds.
> The whole point of powerd is to automatically adapt to the load.  If
> your laptop "lags too much" powerd should detect that and increase the
> CPU frequency.  However, poor interactive response can result when CPU
> frequency fluctuates too quickly; perhaps your problem will go away with
> Andrew's patch, which is intended to dampen such fluctuations?
I'll try this patch, but in my situation powerd drops cpufreq to 300HZ, 
and at this point switching windows (alt-tab) is too lagged.
I do not think that powerd can increase fast enough the freq to let me 
switch between application without lagging
(and without eating too much cpu power).
Hardcoding the minimum to 600HZ (~27% of the CPU power) seems to work 
very good with other default settings on my 2.2GHz core2 duo.
If I'm able to select this through powerd option it will be great.
Also on laptops with ATI cards (FireGL 5200), that run with vesa driver, 
dropping cpufreq under 1GHZ leads to very lagged output in xterm.
It will be great if/when the user can make specific profiles, not just 
having min,adaptive and max profiles.


Best Wishes,
Stefan Lambrev
ICQ# 24134177

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