cvs commit: src/sys/i386/cpufreq est.c

Poul-Henning Kamp phk at
Mon Mar 17 07:02:16 PDT 2008

In message <200803170933.48212.jhb at>, John Baldwin writes:
>On Monday 17 March 2008 05:01:43 am Poul-Henning Kamp wrote:
>> phk         2008-03-17 09:01:43 UTC
>>   FreeBSD src repository
>>   Modified files:
>>     sys/i386/cpufreq     est.c
>>   Log:
>>   Increase time we wait for things to settle to 1 millisecond,
>>   10 microseconds is too short.
>>   Always set the cpu to the highest frequency so that we get through
>>   boot and don't handicap cpus where powerd(8) is not used.
>Hmm, I actually consider this a feature when I'm not running powerd to use 
>less battery.  I think we should only bump up the CPU on battery power when 
>using powerd so that it can be lowered again to save battery power when the 
>CPU is idle.

We have cpufreq enabled by default now, badly configured machines run
at 50% of rated CPU power because people don't know that they need to
enable powerd(8) on servers.

This is only going to get worse when more EnergyStar compliant servers
hit the channel.

I think setting full speed is the correct choice, if people care about
powersaving, they need to configured it, if they don't they should get
their moneys worth out of their hardware.

Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk at 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.

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