Re: HEADSUP: cpufreq import complete, acpi_throttling changed

> Date: Sun, 13 Feb 2005 15:33:27 -0800
> From: Nate Lawson <nate_at_root.org>
> 
> Kevin Oberman wrote:
> >>Date: Sun, 06 Feb 2005 13:21:32 -0800
> >>From: Nate Lawson <nate_at_root.org>
> >>Sender: owner-freebsd-acpi_at_freebsd.org
> >>
> >>
> >>If you have throttling, please test the new configuration to be sure it 
> >>still works as before.  Final upcoming work will be manpage support and 
> >>bugfixing as necessary.
> > 
> > 
> > On my T30, throttling has simply vanished. Kernel sources as of this
> > afternoon at about 11:00 PST.
> > 
> > sysctl hw.acpi does not list any throttling entries at all.
> 
> It shouldn't, they were merged into the sysctl dev.cpu output as you 
> mention below.
> 
> > It does list an amazing number of frequency settings, but only 1800 and
> > 1200 seem to actually work. Perhaps the others are derived by mixing the
> > two capabilities? On the earlier versions of cpufreq I was getting only
> > the two frequencies listed along with the 8 throttling states.
> >
> > Did I miss a message on this?
> 
> Try cvsupping to now.  I did some commits about an hour or two ago that 
> should address throttling not attaching.
> 
> > I am especially concerned because my CPU is now running VERY hot when
> > busy. It never used to exceed about 180F and now it quickly jumps to
> > 190+ when the system is working (such as a buildkernel). Since it was
> > previously running without throttling, I don't understand why things are
> > suddenly worse.
> > 
> > Any idea on what is happening? I don't want to fry my T30.
> 
> One person reported Cx states being broken by the cpufreq import. 
> (Well, actually he got a C3 state that he didn't have before but it 
> didn't work.)  Try setting hw.acpi.cpu.cx_lowest to C1 or something 
> you're sure works.
> 
> Send me the output of sysctl dev.cpu, dmesg, and devinfo -rv.

Things are better now, and it was not really an ACPI issue.

For about the millionth time I remind myself: Only change one thing at a
time!

At the same time that I started running cpufreq and acpi_perf, I also
switched from 4BSD to ULE. This is why the system started running so
much hotter!

Throttling is now working correctly and I can keep my CPU at about 175(F)
degrees or a kernel build by lowering the "frequency" from 1800 to
1350. My dmesg shows ACPI throttling setting up fine:
cpu0: <ACPI CPU (3 Cx states)> on acpi0
acpi_perf0: <ACPI CPU Frequency Control> on cpu0
acpi_throttle0: <ACPI CPU Throttling> on cpu0

I guess all I have really done is demonstrate that ULE is much more
efficient than 4BSD.

Thanks for the quick response and sorry for the false alarm.
-- 
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