tech-kern archive

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Old Index]

Re: A simple cpufreq(9)

On Sat, Sep 24, 2011 at 09:22:58PM +0300, Jukka Ruohonen wrote:
> And as far as x86 is concerned, the power savings from CPU are really coming
> from C-states today. So one can debate whether the 4000 LOC complexity of
> Linux's cpufreq subsystem is really worth the trouble.

What's the difference in power savings between changing C-state and
changing frequency?  Do the power savings from every change in C-state
dominate the savings from any change in frequency?

It seems that ultimately we need an API for telling a power-savings goal
and constraints (latency, throughput, battery life, the screen isn't too
dark to read) for the system to meet.  Do you hope for someone to build
that into the kernel on top of cpufreq(9)?


David Young             OJC Technologies is now Pixo     Urbana, IL   (217) 344-0444 x24

Home | Main Index | Thread Index | Old Index