Problems with amd FX 8 core and freq scaling

[Jung-uk Kim]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

On 2013-11-11 13:16:47 -0500, Nicholas McKenzie wrote:
> But wouldn't this just disable frequency scaling and the whole
> point of powerd?

No.  acpi_throttle (and p4tcc) controls T-state.  "Frequency scaling"
should be done by changing P-state.

> On Mon, Nov 11, 2013 at 1:46 AM, Stefan Esser <se at freebsd.org>
> wrote:
>> 
>> Am 10.11.2013 22:46, schrieb Nicholas Stewart McKenzie:
>>> My computer crashes if I enable powerd. I can't get cpu freq
>>> scaling to work with my cpu:(P.S. I sent this to both drivers
>>> and amd64 mailing list...
>> 
>> Hi,
>> 
>> you may want to try booting with the following line added to 
>> /boot/loader.conf (or entered at the boot menu prompt after 
>> breaking out of automatic boot):
>> 
>> hint.acpi_throttle.0.disabled="1"
>> 
>> There have been a number of reports of throttling causing 
>> crashes. This setting does not prevent powerd from adjusting your
>> CPU's clock, it just disables some arcane feature which pre-dates
>> the modern power management methods.

I rewrote acpi_throttle.c at some point to fix the problem but never
committed it because nobody was really interested in testing the
patch.  Also, it is really an arcane and archaic feature:

http://software.intel.com/en-us/blogs/2013/10/15/c-states-p-states-where-the-heck-are-those-t-states

Now I think we should disable the feature by default because it is
causing too much hassle for us (attached).  Any objection?

Jung-uk Kim
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.22 (FreeBSD)

iQEcBAEBAgAGBQJSgTWNAAoJEHyflib82/FGsqUIAIhv2t69myurKlkZxJw06tjq
47skw20kG1NlxQ97SspL1Blap9yvMkETL3XgR6f6rdgIze8K0wpCIjB19rSg2OIX
yqV1RGC30vWoX2cG4ccKiw8G/juqIbqBpGjHf/pG9LUM4upQQ59gDzkVlCnmorzg
kzBTBEM9TpomqOttB4YICxzkhztcorKJ3cClaPKfoO2Ds9WpQaOYl6b3YW0HUaRW
7VtwjEMDg3BwNoBusBIK+ZLSUSNP5smffX1/oyGHA0QGZCrlMwoH7j5fdZj9weiY
nxM1/jZ+fpiV33jfAt4HzavQDxnpHvYsf5v54Jlmrm+FNtCCp7tWICK/KjVqrn0=
=E6TS
-----END PGP SIGNATURE-----
-------------- next part --------------
A non-text attachment was scrubbed...
Name: cpu_throttle.diff
Type: text/x-patch
Size: 2710 bytes
Desc: not available
URL: <http://lists.freebsd.org/pipermail/freebsd-amd64/attachments/20131111/25da52a4/attachment.bin>