System running hot / CPU freq changes randomly

[Nate Lawson]

Eric Anderson wrote:
> I've jsut upgraded from 5.3-STABLE to -CURRENT, and have a few things 
> I've noticed.  One, my machine runs much hotter - it used to stay around 
> 40 - 41C, but not stays around 49C.  Also, it actually seems like it's 
> running slower - and maybe it is.  It looks like the cpu frequency is 
> changing all the time, hopping around from one freq to another, for no 
> real reason that I can tell.
> I'm running on a dell D600 (1.6GHZ Pentium M), with -CURRENT as of last 
> night.
> I can provide any additional information needed..
> 
> 
> Here's what I mean (on AC, not battery):
> [ 12:48:25 root at neutrino ~ ]# sysctl dev.cpu.0.freq
> dev.cpu.0.freq: 1600
> [ 12:48:27 root at neutrino ~ ]# sysctl dev.cpu.0.freq
> dev.cpu.0.freq: 400
> [ 12:48:28 root at neutrino ~ ]# sysctl dev.cpu.0.freq
> dev.cpu.0.freq: 400

Are you running powerd?  If you have powerd_enable="YES" in 
/etc/rc.conf, it defaults to adaptive control.  I _thought_ I made the 
default "NO" until we get more testing.

> hw.acpi.cpu.cx_supported: C1/1 C2/1 C3/85 C4/185
> hw.acpi.cpu.cx_lowest: C1
> hw.acpi.cpu.cx_usage: 100.00% 0.00% 0.00% 0.00%

I had to disable C2 and higher by default due to some C3 problems some 
users were having.  Hopefully we'll sort this out at some point and 
re-enable it by default.

You can get the old values back through /etc/rc.conf.  Add:

performance_cx_lowest="LOW"
economy_cx_lowest="LOW"

(Or explicitly use "C3" if C4 doesn't work right for you).

-- 
Nate