Avoiding "WARNING: system temperature too high, shutting down soon!"?

[David Wolfskill]

I could use some help:  I seem to overheat my laptop; I'd like to get
some idea of how to avoid the overheating, preferably while still
getting the work done.

The laptop is a Dell Inspiron 8200.  I recently bought this one to
replace a 1.6 GHz one that had developed an occasional problem with
the LCD display that made the display unusable (though I could SSH in to
the machine usually).  This machine is a 2.4 GHz P4M with 768 MB RAM (at
the moment).

During Nate's BAFUG talk earlier this month, I decided to try running
powerd; I set the mode at "adaptive" for AC, battery, and unknown, and
dev.cpu.0.freq reports that it normally sits at 150, but appears to ramp
up quite responsively during, say, a "make buildworld."  (The eralier
laptop sits at dev.cpu.0.freq=1600 during that process; the current one
sits at 2400 -- as expected).

However, the temperature (as reported by hw.acpi.thermal.tz0.temperature),
which meanders between 52 - 62C while the machine isn't doing much,
tends to spend long stretches of time in the 80 - 90C range during a
"make buildworld" (as reported by a "while (1)" loop during said
process).  As you can see from the salient sysctl values, that's not a
lot of headroom:

g1-18(6.2-P)[4] sysctl hw.acpi.thermal dev.cpu.0
hw.acpi.thermal.min_runtime: 0
hw.acpi.thermal.polling_rate: 10
hw.acpi.thermal.user_override: 0
hw.acpi.thermal.tz0.temperature: 58.5C
hw.acpi.thermal.tz0.active: -1
hw.acpi.thermal.tz0.passive_cooling: 0
hw.acpi.thermal.tz0.thermal_flags: 0
hw.acpi.thermal.tz0._PSV: -1
hw.acpi.thermal.tz0._HOT: -1
hw.acpi.thermal.tz0._CRT: 94.0C
hw.acpi.thermal.tz0._ACx: -1 -1 -1 -1 -1 -1 -1 -1 -1 -1
dev.cpu.0.%desc: ACPI CPU
dev.cpu.0.%driver: cpu
dev.cpu.0.%location: handle=\_PR_.CPU0
dev.cpu.0.%pnpinfo: _HID=none _UID=0
dev.cpu.0.%parent: acpi0
dev.cpu.0.freq: 150
dev.cpu.0.freq_levels: 2400/0 2100/0 1800/0 1500/0 1200/0 1050/0 900/0 750/0 600/0 450/0 300/0 150/0
g1-18(6.2-P)[5] 

leading to:

Sep 16 10:11:43 localhost root: WARNING: system temperature too high, shutting down soon!
Sep 16 10:11:43 localhost syslogd: /dev/:0: No such file or directory
Sep 16 10:11:49 localhost kernel: acpi_tz0: WARNING - current temperature (94.5C) exceeds safe limits
Sep 16 10:11:55 localhost syslogd: exiting on signal 15

this morning while I was running yesterday's -CURRENT, building today's.
(I had already built today's -STABLE, aka -6.2-PRERELEASE successfully.)

And that's the work that I'd like to be able to do:  track RELENG_6
& HEAD on a daily basis.  With a few interruptions, mostly from
events not of my choosing, I've been doing this with various machines,
including laptops, for some years.

I suppose it's possible that the cooling just isn't adequate for the
machine, though each of the 2 fans appears to operate.  (Each has a
"high", "low", and "off" setting; one fan is for the CPU; the other is
for the motherboard -- per Dell's diagnostics.  The motherboard fan
does make an odd sound sometimes, though the diagnostics claim that it
was running fine.)

Just prior to the forced shutdown (above), the reported temperature
had been >90C for several minutes, and the fans were going full
bore.  I had elevated the laptop above a smooth flat surface, then
put a bag of ice under it -- apparently to no avail.

So:  in the face of prolonged near-critical temperatures, is there a way
to tell the machine to throttle back & work a bit less hard?  OF course,
if there's a way to make the cooling more effective, I'd certainly be
interested in that, as well -- but having the machine shut down like
that is awfully disruptive.  :-/

Please include me in responses, as ACPI isn't one of the things I follow
closely enough to subscribe to the list.

I will, of course, summariize responses sent off-list that appear to be
useful.

Thanks!

Peace,
david
-- 
David H. Wolfskill				david at catwhisker.org
Believe SORBS at your own risk: 63.193.123.122 has been static since Aug 1999.

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