Local photography, National rants, Zero navel-gazing allowed… Blogging from Hopkinsville, KY

hrtimers is DA BOMB!

Last night, I patched a vanilla 2.6.22 kernel with the hrtimers code and I’m still finding all the magic things it can do. Two of the biggest things are the cpuidle governor and hpet support. cpuidle “menu” governor allows the cpu to drop into the lowest C-state possible without passing through any other states. The difference is dramatic, without hrtimers ipw2200 would not allow the cpu lower than C2, now the cpu spends 80% of it’s time in C4. HPET replaces the old timer code that woke up a minimum of 30 times a second. With HPET running, this floor is removed and the computer can idle at two wakeups per second if there are no heavy services running!

PowerTOP 1.8 has been released. Feaures like deferrable timers depend on Linux 2.6.23 but a new dump mode will be useful to capture data.