Re: power management regression in linux 3.10?

[Dirk Brandewie <dirk.brandewie@gmail.com>]

On 06/03/2013 12:34 PM, Rafael J. Wysocki wrote:
> On Monday, June 03, 2013 07:56:15 PM Michael Karcher wrote:
>> Hello,
>>
>> I am using an IBM ThinkPad T60 (i915, Core 2 Duo T7200) and recently
>> upgraded from a custom 3.7 kernel to a custom 3.10-rc4 kernel
>> (v3.10-rc4-1-gc026d8e).
>> After upgrading, I get around 17-20W power usage instead of 12-15W power
>> usage as I had with 3.7. powertop show that CPU0 is in state POLL all of
>> the idle time, while CPU1 correctly enters C3.
>>
>> As this may be caused by my kernel configuration, I pastebinned
>> my .config to http://pastebin.ca/2388457. Note that I am using
>> CONFIG_NO_HZ_FULL, which might be nonstandard and actually not sensible
>> for a standard single-user laptop system with GUI.
>>
>> Do you want me to try something to debug the problem?
>
> Yes, please try with CONFIG_NO_HZ_IDLE and see if you can reproduce the
> problem.
>
> Does your system use intel_idle?  You've set that in .config, but can you check
> what dmesg says, please?
>
> Rafael
>
>

Unset CONFIG_NO_HZ it is setting CONFIG_CPU_IDLE_GOV_MENU which with 
CONFIG_NO_HZ_FULL set is confusing intel_pstate.  I am still trying to
figure out what the root cause is commit 5811d996 seems to be implicated.

--Dirk