[RFC] Patch to enable temperature ceiling in powerd

[Hajimu UMEMOTO]

Hi,

>>>>> On Wed, 30 Jan 2008 17:56:19 -0500
>>>>> "Alexandre \"Sunny\" Kovalenko" <alex.kovalenko at verizon.net> said:

alex.kovalenko> Some time ago I have put together patch for powerd, which allows user to
alex.kovalenko> specify the temperature threshold at which powerd will lower CPU
alex.kovalenko> frequency no matter what the load was at the time. I recently had to
alex.kovalenko> adapt it to the 7.0-PRERELEASE for someone with the overheating laptop,
alex.kovalenko> which got me to think that it might be useful for someone else yet.

alex.kovalenko> Basic idea is fairly simple -- check temperature in TZ0 and, if it has
alex.kovalenko> reached certain value, either override frequency with the lowest
alex.kovalenko> available (in the case of 'max' setting) or change idle time to 100% and
alex.kovalenko> let adaptive algorithm decrease frequency gradually.

alex.kovalenko> I imagine it also could be poor man's substitute for the low noise
alex.kovalenko> acoustic policy ;)

alex.kovalenko> If there is an interest, I will go ahead and submit a PR, otherwise it
alex.kovalenko> will live in the mail archives for someone to find. Any comments,
alex.kovalenko> suggestions or criticisms are welcome.

alex.kovalenko> Temperature threshold (in Celsius) could be set by means of '-T' command
alex.kovalenko> line option (as in '-T 60').

Our kernel has passive cooling feature, already.  Is it not enough for
you?

Sincerely,

--
Hajimu UMEMOTO @ Internet Mutual Aid Society Yokohama, Japan
ume at mahoroba.org  ume@{,jp.}FreeBSD.org
http://www.imasy.org/~ume/