weird interrupts

[Kalmár Dániel]

Hi!

I recently started using powertop on my brand new laptop, and I have a few things to ask and to suggest.

I have 300-700 wakeups per second, which seems really high. I have no idea why, even if I switch everything off, and nothing shows more than 5 interrups in the detailed list, I still get 300 wakeups per sec. Any idea why?

I've read somewhere that JFS uses 30% less CPU and disk power than ext3 or reiserfs. Is this true? I've converted to JFS a few days ago, but I'm not sure if there's actually any difference.

Does turning off one of the CPUs (hotplugging works on my core 2 duo) save power? I did some tests and it seems like it doesn't affect power usage at all (but the 2nd core is reported to be turned off by the kernel).

Does lowering the cpu frequency save a lot of power? My default setting is the conservative governor, but when I run the laptop on battery I usually set the frequency to the lowest possible constantly. Should I keep doing this or just stick to conservative?

Some people on this list said that ondemand is better for intel CPUs. I know that it's better performance-wise (as it switches to the highest possible frequency faster), but is it better power-saving-wise?

And a suggestion: there are many suggested kernel options that are not actually useable on specific architectures. For example I use a 64-bit linux kernel, and it doesn't have the CONFIG_NO_HZ option (it's x86 only afaik), still it keeps showing up as a suggestion.

Maul

PS. powertop came out 2 days after I bought the laptop, so it must be a sign or something :)