[arch-general] powertop vs archlinux vs ubuntu

[Andrea Fagiani]

On 02/22/2010 09:04 AM, Stefano Z. wrote:
> no, my dual celeron su2300 dosen't support speedstep, it stay fixed to 1.2ghz
> but i have found the problem, i think this problem have to do with KMS...
> I have istalled kernel26 2.6.31.6-1 and the problem disappered but obviously
> this is not the solution i want ;-)
> If i install 2.6.32+ kernel the problem reappear.
> Another thing that happens is that the cpu(s) Temperature with kernels
>    
>> 2.6.31 stay
>>      
> about on 53+C while with kernel<2.6.32 stays on 42C...
>
>
>
> On Mon, Feb 22, 2010 at 9:43 AM, Andrea Fagiani<andfagiani at gmail.com>  wrote:
>    
>> On 02/22/2010 04:53 AM, Brendan Long wrote:
>>      
>>> On 02/21/2010 04:55 PM, Xavier Chantry wrote:
>>>
>>>        
>>>> On Mon, Feb 22, 2010 at 12:42 AM, Stefano Z.<mie.iscrizioni at gmail.com>
>>>>   wrote:
>>>>
>>>>
>>>>          
>>>>> hi
>>>>>
>>>>> i've bought a new notebook (hp pavilion dm1-1150sl) and installed
>>>>> archlinux.
>>>>> i have see a strange thing with powertop, i'm running the vanilla arch
>>>>> kernel26,
>>>>> and i have see this behaviour:
>>>>> Cn                Avg residency       P-states (frequencies)
>>>>> C0 (cpu occupata)      (31,6%)
>>>>> C0                0,0ms ( 0,0%)
>>>>> C1 mwait          0,1ms ( 0,7%)
>>>>> C4 mwait          0,0ms (67,8%)
>>>>> Wakeups-from-idle per second : 31483,5  interval: 10,0s
>>>>> ---
>>>>> as you can see, i have a LOT of wakeups per seconds very low c1 states
>>>>> lot of c0 and c4 states,
>>>>> a wattmeter tell me that archlinux consume about 25/26watt
>>>>> Then i have boot a live ubuntu distro and see this:
>>>>> Cn                permanenza media    P-state (frequenze)
>>>>> C0 (cpu occupata)      ( 0,6%)
>>>>> polling           0,0 ms ( 0,0%)
>>>>> C1 mwait         26,7 ms (68,6%)
>>>>> C4 mwait          1,2 ms (30,8%)
>>>>> Wakeup-da-idle al secondo: 281,3        intervallo: 15,0s
>>>>> ---
>>>>> as you can see  the wakeups are a LOT lower than on arch and we have
>>>>> lot of c1 and c4 state,
>>>>> power consumption is about 20W, the same that i have with win7 (about
>>>>> 18/20w).
>>>>> For meaning about cX state see here:
>>>>> http://www.lesswatts.org/projects/powertop/powertop.php
>>>>>
>>>>> thanks!
>>>>>
>>>>>
>>>>>
>>>>>            
>>>> You didn't give enough information so we will need to check the basis :
>>>> - which cpufreq driver and governor are you using in both cases (check
>>>> cpufreq-info)
>>>> - what processes does powertop show as causes for wakeups ?
>>>> - what processes does top show in term of cpu usage ?
>>>>
>>>> Here is what I got in the last few minutes when i was writing this :
>>>> C4 mwait          3.4ms (92.5%)          800 Mhz    98.0%
>>>> Wakeups-from-idle per second : 279.4    interval: 10.0s
>>>>
>>>> I have a core 2 duo with acpi-cpufreq loaded and conservative governor.
>>>> $ grep cpufreq /etc/rc.conf
>>>> MODULES=(acpi-cpufreq)
>>>> DAEMONS=(syslog-ng net-profiles crond dbus hal alsa cpufreq
>>>> storage-fixup)
>>>> $ grep governor /etc/conf.d/cpufreq
>>>> # valid governors:
>>>> governor="conservative"
>>>>
>>>>
>>>>          
>>> They may just not have cpu-freq-utils installed maybe? I'm using
>>> laptop-mode-tools with compiz and GNOME running (but not doing anything)
>>> and it's saying 99.2% C4, 0.8% C0. This is with another Core2 and
>>> laptop-mode is set to use the powersave governor on battery (which is
>>> how I tested). When I plug it in, it jumps up to 25%, but I don't really
>>> care how active the processor is when it's on battery.
>>>
>>>
>>>        
>> Be sure to have cpu-freq-utils installed, as well as loading the right
>> modules (acpi-cpufreq, cpufreq_ondemand, if you plan on using the same
>> governor as ubuntu does), and add `cpufreq` to your DAEMONS array in
>> rc.conf.
>> On my system, with laptop-mode-tools the powertop output is very similar to
>> what Brendan said. Also, the 31k+ wakeups definitely mean there's some issue
>> on your config.
>>
>>      
>    
If you think it's KMS causing problems, try adding `nomodeset` to your 
kernel boot line and see what happens.