How/why would dev.cpu.0.freq_levels change??!?

[David Wolfskill]

My laptop is a Dell Inspiron 8200; I (ab)use it moderately heavily:
this includes tracking RELENG_6, RELENG_7, & HEAD on it, daily.

Lately there have been some times when "make buildworld" for RELENG_6
has taken a lot longer than it used to ... and I noticed that the
fans were on, even though it was running fairly cool (around 50C;
during a "make buildworld, around 85C is more common) -- and that
the machine was typically "topping out" at half speed (1200 MHz).

During these times, querying dev.cpu.0.freq_levels would yield a list
that did, ini fact, max out at 1200 MHz, when I know that it has gone up
to 2400 MHz in the past.

When it does this, the only circumvention I've been able to find is a
power-cycle.  Since I like to minimize disruption, this is annoying.

This afternoon, it showed evidence of doing this stunt again, so I
carefully logged out, powered the machine off, waited about 5 minutes,
then powered it back on.

But this time, I decided to fire up a little loop to display a timestamp
and the ooutput from "sysctl -n hw.acpi.thermal.tz0.temperature
dev.cpu.0.freq dev.cpu.0.freq_levels" every 5 seconds.

Here's the interval in question:

1214609737,60.5C,300,2400/0 2100/0 1800/0 1500/0 1200/0 1050/0 900/0 750/0 600/0 450/0 300/0 150/0
1214609742,59.5C,450,2400/0 2100/0 1800/0 1500/0 1200/0 1050/0 900/0 750/0 600/0 450/0 300/0 150/0
1214609748,59.5C,450,2400/0 2100/0 1800/0 1500/0 1200/0 1050/0 900/0 750/0 600/0 450/0 300/0 150/0
1214609752,57.5C,150,2400/0 2100/0 1800/0 1500/0 1200/0 1050/0 900/0 750/0 600/0 450/0 300/0 150/0
1214609757,57.5C,600,1200/0 1050/0 900/0 750/0 600/0 450/0 300/0 150/0
1214609762,56.5C,150,1200/0 1050/0 900/0 750/0 600/0 450/0 300/0 150/0
1214609767,56.5C,150,1200/0 1050/0 900/0 750/0 600/0 450/0 300/0 150/0

And from a couple of logs:

g1-60(6.3-S)[5] date -r 1214609752
Fri Jun 27 16:35:52 PDT 2008
g1-60(6.3-S)[6] date -r 1214609757
Fri Jun 27 16:35:57 PDT 2008
g1-60(6.3-S)[7] tail -4 /var/log/messages
Jun 27 16:01:51 localhost kernel: drm0: [MPSAFE]
Jun 27 16:20:57 localhost ntpd[13916]: time reset +1.306598 s
Jun 27 16:38:55 localhost sudo:    david : TTY=ttyp7 ; PWD=/common/home/david ; USER=root ; COMMAND=/usr/bin/tail /var/log/console.log
Jun 27 16:45:34 localhost ntpd[13916]: kernel time sync enabled 2001
g1-60(6.3-S)[8] sudo tail -4 /var/log/console.log
Password:
Jun 27 16:01:47 localhost kernel: .
Jun 27 16:01:47 localhost kernel: Starting background file system checks in 60 seconds.
Jun 27 16:01:47 localhost kernel: 
Jun 27 16:01:47 localhost kernel: Fri Jun 27 16:01:47 PDT 2008
g1-60(6.3-S)[9] dmesg | tail -4
info: [drm] Setting GART location based on new memory map
info: [drm] Loading R200 Microcode
info: [drm] writeback test succeeded in 1 usecs
drm0: [MPSAFE]
g1-60(6.3-S)[10] 

So: nothing logged.  And I know of no way to change the value, but
something did.

Any clues?

Oh:  the machine is presently running:

g1-60(6.3-S)[10] uname -a
FreeBSD g1-60.catwhisker.org 6.3-STABLE FreeBSD 6.3-STABLE #638: Fri Jun 27 08:09:17 PDT 2008     root at g1-60.catwhisker.org:/common/S1/obj/usr/src/sys/CANARY  i386
g1-60(6.3-S)[11] 

Please include me in responses, as I'm not subscribed to -acpi at .

Thanks!

Peace,
david
-- 
David H. Wolfskill				david at catwhisker.org
I submit that "conspiracy" would be an appropriate collective noun for cats.

See http://www.catwhisker.org/~david/publickey.gpg for my public key.
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