RE: [intel-pstate driver regression] processor frequency very high even if in idle

From: Doug Smythies
Date: Thu Mar 31 2016 - 10:30:16 EST


On 2016.03.31 01:11 Sedat Dilek wrote:
> On Thu, Mar 31, 2016 at 12:50 AM, Doug Smythies <dsmythies@xxxxxxxxx> wrote:
>> On 2106.03.30 15:19 Srinivas Pandruvada wrote:
>>>>
>>>> Please see attached files.
>>>>
>>> Thanks. Your logs make sense. You have config set to performance mode
>>> by default (Which I believe default in all kernel Ubuntu).
>>
>> Yes, but via a startup script, by default Ubuntu sets the governor
>> to powersave 1 minute after boot (or ondemand if acpi-cpufreq).
>>
>
> Can you give more and precise informations on this?
> script-name etc.

The script is /etc/init.d/ondemand
It sleeps for 1 minute and then sets the scaling
governor, based on availability, in the following order:
interactive
ondemand
powersave

See also:

$ ls -l /etc/rc?.d/S06ondemand
lrwxrwxrwx 1 root root 18 Mar 8 09:51 /etc/rc2.d/S06ondemand -> ../init.d/ondemand
lrwxrwxrwx 1 root root 18 Mar 8 09:51 /etc/rc3.d/S06ondemand -> ../init.d/ondemand
lrwxrwxrwx 1 root root 18 Mar 8 09:51 /etc/rc4.d/S06ondemand -> ../init.d/ondemand
lrwxrwxrwx 1 root root 18 Mar 8 09:51 /etc/rc5.d/S06ondemand -> ../init.d/ondemand

>From your other e-mail:

> is somehow showing higher
> values than TSC_MHz.
> Not sure if this really make sense if TSC_MHz is a max-value (which I
> don't know it is).

That is normal, and is turbo mode. Example:

$ sudo turbostat -i 3 --msr=0x199
CPU Avg_MHz %Busy Bzy_MHz TSC_MHz MSR 0x199
- 478 12.53 3798 3413 0x00000000
0 3 0.09 3595 3413 0x00002500
4 1 0.03 3568 3413 0x00001000
1 4 0.11 3649 3413 0x00001200
5 2 0.07 3592 3413 0x00001000
2 3 0.08 3628 3413 0x00001000
6 1 0.03 3546 3413 0x00001000
3 1 0.02 3733 3413 0x00001000
7 3808 99.91 3799 3411 0x00002600

... Doug