Arch Linux

FallenSnow

Member

Registered: 2014-04-07

Posts: 39

Does Arch support core parking?

I don't know if this falls under the Linux kernel or arch but is there any core parking support? I'm trying to squeeze as much energy efficiency out of my server as possible.

mich41

Member

Registered: 2012-06-22

Posts: 796

Re: Does Arch support core parking?

Modern CPUs are said to eat little power in deep C states, so enable all power-saving features in BIOS and use CPUFreq ondemand.

It's possible to take a core offline with

echo 0 >/sys/devices/system/cpu/cpuN/online

Maybe there are userspace scripts/programs which do it automatically, if not you could probably hack something. AFAIK there is no way to make the kernel do it by itself. And I'm not sure if it's significantly better than deep C states so you may want to measure this first by taking cores offline manually.

Last edited by mich41 (2016-06-23 21:43:17)

brebs

Member

Registered: 2007-04-03

Posts: 3,742

Re: Does Arch support core parking?

I'm trying to squeeze as much energy efficiency out of my server as possible.

How much of a performance degredation are you willing to accept?

You could try setting the speed of each CPU core to its minimum.

CPU undervolting is worth checking out.