[ltp] CPU running ??? but why????

Arno Trautmann linux-thinkpad@linux-thinkpad.org
Sun, 08 Jun 2008 13:25:33 +0200


Florian Reitmeir wrote:
> On Sat, 07 Jun 2008, Peter F. Patel-Schneider wrote:
> 
>> As far as I know, this is an unexplained phenomenon that has been around
>> for at least a year now.  My Lenovo T60p exhibits this behaviour
>> sometimes, but not all the time.  Even more strangely, the aberrant
>> behaviour comes and goes - for a few days it happens quite reqularly,
>> then there is no problem for weeks on end.
>>
>> Several people, myself included, have asked in various fora about the
>> problem, including the powertop mailing list, accessible at
>>   http://www.bughost.org/mailman/listinfo/power
>> see 
>>   http://www.bughost.org/pipermail/power/2007-May/000337.html 
>> for the first report that I can find.  I just noticed a recent report on
>> the problem
>>   http://www.bughost.org/pipermail/power/2008-June/001371.html
>>
>> So what is causing the problem?  The guessing, and as far as I know it
>> is only guessing, is that some DMA activity is causing the wakeups, but
>> I don't even know enough about the situation to figure out whether
>> explanation makes any sense.  Even if this is the case, I haven't seen
>> any hints on how to attempt to fix the problem, or even which of the
>> many devices built in to my T60p is the source.  I don't even know how
>> widespread the problem is.
>>
>> All in all, quite frustrating.
> 
> just run powetop in one terminal
> and run an other terminal in which you remove kernel modules, one by one.
> 
> typical these kernel modules first:
> 	- usb
> 	- firewire
> 	- sound hardware
> 	- yenta socket
> 
> take your time, if its a hardware problem you should be able to debug it, in
> about 30 mins.

That sounds good… but I don’t have any idea how to do this… I’m quite 
new to linux, so could you give me some concrete commandos or a page 
where I can find some examples? I would be very happy if I could track 
it down on this way!

Thanks,
Arno