I have Impossible throttling.

[Shannon McMackin]

On 07/09/2009 10:24 PM, Paul Johnson wrote:
> In this website, the argument is made that newer CPUs will use MORE
> energy if the throttling level is set to any value except T0.
>
> http://www.thinkwiki.org/wiki/How_to_make_use_of_Dynamic_Frequency_Scaling
>
> Throttling is "old fashioned", I gather.
>
> I had not bothered with cpuscaling/throttling for about 2 years, so
> that claim surprised me and I started checking.  My battery life in
> Linux is worse than it is in WinXP on the same laptop, so I figured I
> might do better.
>
> I have no trouble adjusting the cpuspeed (or do we say cpufreq these
> days?) with the gnome applet "CPU Frequency Scaling Monitor".  I have
> experimented with the "ondemand" and "conservative" governors.
>
> The throttling has me puzzled, though.
>
> It appears my Lenovo T61 running Ubuntu 9.04 with kernel
> 2.6.28-13-generic is in a throttling state T8 that does not exist!
>
>
> $  sudo cat /proc/acpi/processor/CPU0/throttling
>
> state count:             8
> active state:            T8
> state available: T0 to T7
> states:
>      T0:                  100%
>      T1:                  88%
>      T2:                  75%
>      T3:                  63%
>      T4:                  50%
>      T5:                  38%
>      T6:                  25%
>      T7:                  13%
>
> What the heck is T8? That appears to be impossible, since the valid
> states are T0-T7.
>
> I suspected it meant that throttling was disabled, but no! observe:
>
> # cat /proc/acpi/processor/CPU0/info
> processor id:            0
> acpi id:                 0
> bus mastering control:   yes
> power management:        yes
> throttling control:      yes
> limit interface:         yes
>
>
>
> If I want to force the system to always stay in T0, what should I do?
> I can't see any way to do this as a nonroot user or with su.
>
> I can get there with
>
> $ sudo su
>
> $ echo 0>  /proc/acpi/processor/CPU0/throttling
>
> I have no actual evidence that this helps, but the ThinkWiki site
> claims it will.
>
> Once I learn the "right" setting, I'd like to fix it permanently.
>
> If I knew the correct syntax, I could put it in /etc/sysfs.conf.
>
> Right?
>
>
That's interesting...

I have a T61 running F11 and mine shows T0, but I can see that the 
applet is down to 800MHz.

CPU1 shows the same.

If I get a chance, I'll fire up my Ubuntu disk and see what it shows...