[patch] enhance powerd(8) to handle max temperature
oberman at es.net
Thu Aug 2 04:50:15 UTC 2007
> > Garrett Cooper wrote:
> >> M. Warner Losh wrote:
> >>> In message: <46AE8F78.1060203 at root.org>
> >>> Nate Lawson <nate at root.org> writes:
> >>> : Hajimu UMEMOTO wrote:
> >>> : >>>>>> On Mon, 30 Jul 2007 23:31:33 +0200
> >>> : >>>>>> Pietro Cerutti <gahr at gahr.ch> said:
> >>> : > gahr> My patch is really just a first draft that I wrote in order
> >>> to have
> >>> : > gahr> feedbacks on the general idea to implement a temperature
> >>> controlling
> >>> : > gahr> system inside powerd, and doesn't implement hysteresis as
> >>> you noted, and
> >>> : > gahr> your feedback is that it's not a good idea, which I respect.
> >>> : > : > It is rather backward, IMHO. I did implement a passive cooling
> >>> : > feature as an enhancement of powerd(8) like you did, during initial
> >>> : > phases. Then, I implemented it in our kernel as a result.
> >>> : : I'll take a look at your patch. Umemoto-san is right in that you
> >>> really
> >>> : want the kernel to control cooling. What happens if powerd dies/hangs
> >>> : and your system burns up? Passive cooling is often a last resort to
> >>> : keep the system from overheating.
> >>> I keep getting the system shutting down on my HP by FreeBSD because
> >>> the temperature exceeds the _CRT value. Maybe there's something wrong
> >>> with my values, since it happens a lot:
> >>> hw.acpi.thermal.min_runtime: 0
> >>> hw.acpi.thermal.polling_rate: 10
> >>> hw.acpi.thermal.user_override: 0
> >>> hw.acpi.thermal.tz0.temperature: 0.0C
> >>> hw.acpi.thermal.tz0.active: -1
> >>> hw.acpi.thermal.tz0.passive_cooling: 1
> >>> hw.acpi.thermal.tz0.thermal_flags: 0
> >>> hw.acpi.thermal.tz0._PSV: 90.0C
> >>> hw.acpi.thermal.tz0._HOT: -1
> >>> hw.acpi.thermal.tz0._CRT: 94.0C
> >>> hw.acpi.thermal.tz0._ACx: 40.0C -1 -1 -1 -1 -1 -1 -1 -1 -1
> >>> Note: temperature is always 0.0C.
> >>> What can I do to help my situation, if I really want the kernel doing
> >>> the cooling?
> >>> Warner
> >> Wow, something's really wrong with those calculated temperatures. At
> >> that value most of the plastic and weaker circuitry should have fused
> >> together =\.
> > It would be interesting to see what the values are just after booting,
> > or even earlier if you can get the bios to give temperatures (some MBs
> > have that possibility)
Not really. My ThinkPad shows even higher values and I am convinced that they
hw.acpi.thermal.tz0._ACx: -1 -1 -1 -1 -1 -1 -1 -1 -1 -1
These are correct. During heavy compute use, I have seen my laptop CPU at 86C. Nothing melts. According to the other five sensors, nothing ouside of the CPU is anywhere near that hot. (It does get hot enough under the heat pipes and sink to be very uncomfortable when used as a literal laptop.)
The CPU temperature is measured by a junction in the chip and it is the hottest point in the machine (unless you have a hot GPU). The days of sensors on the mobo that show an external temp are pretty much over as all recent AMD and Intel chips have internal sensors. If you check the spec sheets, many recent chips are rated for operating at internal temps of 100C and higher.
R. Kevin Oberman, Network Engineer
Energy Sciences Network (ESnet)
Ernest O. Lawrence Berkeley National Laboratory (Berkeley Lab)
E-mail: oberman at es.net Phone: +1 510 486-8634
Key fingerprint:059B 2DDF 031C 9BA3 14A4 EADA 927D EBB3 987B 3751
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