Hi
I'm noticing strange behavior on my T61.
When I select performance governor for my CPU I still get occasional
drop on CPU frequency from 2.2.GHz to 800MHz.
I'm attaching my .config file.
How it could happen that perfomance is actually able to change
frequency from it's highest mode - is it because of some overheating ?
(It usually happens when I run make -j2 - even just for a minute -
it suddenly start to drop the CPU to lowest clock rate -
imho I think the machine is quite calm to be 'overheated')
What other debug info is needed ?
affected_cpus
0 1
cpuinfo_cur_freq
2201000
cpuinfo_max_freq
2201000
cpuinfo_min_freq
800000
related_cpus
0 1
scaling_available_frequencies
2201000 2200000 1600000 1200000 800000
scaling_available_governors
ondemand performance
scaling_cur_freq
2201000
scaling_driver
acpi-cpufreq
scaling_governor
performance
scaling_max_freq
2201000
scaling_min_freq
800000
scaling_setspeed
<unsupported>
stats/time_in_state
2201000 331831
2200000 2876
1600000 1739
1200000 3398
800000 512768
(btw why do I have two states - 2201000 and 2200000 ??)
Zdenek
On Mon, 15 Dec 2008, Zdenek Kabelac wrote:
> Hi
>
> I'm noticing strange behavior on my T61.
>
> When I select performance governor for my CPU I still get occasional
> drop on CPU frequency from 2.2.GHz to 800MHz.
>
> I'm attaching my .config file.
>
> How it could happen that perfomance is actually able to change
> frequency from it's highest mode - is it because of some overheating ?
performance governor itself will not change the frequency.
> (It usually happens when I run make -j2 - even just for a minute -
> it suddenly start to drop the CPU to lowest clock rate -
> imho I think the machine is quite calm to be 'overheated')
>
> What other debug info is needed ?
>
>
> affected_cpus
> 0 1
> cpuinfo_cur_freq
> 2201000
> cpuinfo_max_freq
> 2201000
> cpuinfo_min_freq
> 800000
> related_cpus
> 0 1
> scaling_available_frequencies
> 2201000 2200000 1600000 1200000 800000
> scaling_available_governors
> ondemand performance
> scaling_cur_freq
> 2201000
> scaling_driver
> acpi-cpufreq
> scaling_governor
> performance
> scaling_max_freq
> 2201000
> scaling_min_freq
> 800000
> scaling_setspeed
> <unsupported>
>
>
> stats/time_in_state
> 2201000 331831
> 2200000 2876
> 1600000 1739
> 1200000 3398
> 800000 512768
>
>
> (btw why do I have two states - 2201000 and 2200000 ??)
2201000 is the marketing speed of your processor, plus 1MHz.
This is used by the ACPI BIOS to enable "Turbo Mode",
aka Intel Dynamic Acceleration Technology --
which gives the harware license to run faster than
2.2GHz if the conditions are right.
ie. when there is still no idle time available at 2.2GHz,
ondemand chooses 2.21 Ghz, and the HW may give it more...
The right conditions depend on the part -- could be that
some cores need to be in deep idle to let other cores
go fast, or it could be based on current and thermal
constraints, or both.
I have a 2.0 GHz T61, and I'm unable to reproduce
your observation.
You can eliminate turbo from the picture by
echo 2200000 > time_in_state
and that will tell us if turbo is related to your
occasional obervance of low-frequency-mode.
You can also observe the temperature in
/proc/acpi/thermal*/*/temperature
cheers,
-Len
> I'm noticing strange behavior on my T61.
>
> When I select performance governor for my CPU I still get occasional
> drop on CPU frequency from 2.2.GHz to 800MHz.
afaict, it is a bios issue ... on my thinkpad t60, the bios can be
configured to covern the clock speed ... there is `thermal mode' option,
where you can choose something like `full performance' and a `thermal
optimized' ... i don't remember the full option name, but it is somehow
named this way ...
on my t60 the cpu was clocked down sometimes in order to keep the cpu
temperature below 70ĚŠ until i switched to `full performance' ...
hth, tim
--
[email protected]
http://tim.klingt.org
The price an artist pays for doing what he wants is that he has to do
it.
William S. Burroughs
On Mon, Dec 15, 2008 at 12:59:15PM -0500, Len Brown wrote:
> and that will tell us if turbo is related to your
> occasional obervance of low-frequency-mode.
We've observed this on certain other pieces of modern Intel hardware -
the best hypothesis we've been able to come up with is that if the msr
read is the first instruction run on the core when it's previously been
in a deep C state, the low-clock speed is reported. However, some
Thinkpads will also automatically limit their speed for thermal reasons.
--
Matthew Garrett | [email protected]