90 wakeups per second on idle ide0

[Arjan van de Ven]

Jan Ceuleers wrote:
> All,
> 
> I've just begun using powertop to look at the behaviour of one of my 
> machines. The most surprising (to me, at least) result is the fact that 
> most of the time, the ide0 interrupt is the most prominent reason for 
> wakeups at ~90/s.
> 
> That's surprising because the machine is diskless. The ide0 interface 
> does serve a DVD drive, but it's idle (no disk in the drive).
> 
> This is Ubuntu 7.10 with kernel "Linux fe2 2.6.22-14-generic #1 SMP Tue 
> Feb 12 07:42:25 UTC 2008 i686 GNU/Linux" on a Via Epia EN15000G mobo 
> (Via C7 CPU). Powertop is version 1.9 as downloaded from the Ubuntu 
> repository.
> 
> I'd be grateful for any hints as to how to diagnose this. I did look at 
> the known issues page at lesswatts.org.
> 

this is very likely the hal storage daemon polling your cdrom to see if you put a CD in it.