lowest C-state changes

[Ivan Klymenko]

В Thu, 05 Apr 2012 13:15:35 +0300
Volodymyr Kostyrko <c.kworr at gmail.com> пишет:

> Любомир Григоров wrote:
> > Hello all, I am using FreeBSD 9.0-STABLE with Konstantin's patch
> > from March 22nd. Everything else is stock. However, after heavy
> > load, or compiling, C-states go to C1 as lowest. I think once they
> > pass the threshold, they don't go back.
> >
> > ThinkPad X220
> > i5 2520M with integrated Intel video
> >
> > In /etc/sysctl.conf
> > dev.cpu.0.cx_lowest=C3
> > dev.cpu.1.cx_lowest=C3
> > dev.cpu.2.cx_lowest=C3
> > dev.cpu.0.cx_lowest=C3
> >
> > In /etc/rc.conf
> > powerd_enable="YES"
> > powerd_flags="-a hiadaptive -b adaptive -i 85 -r 60 -p 100"
> >
> > However, once the  cores go to C1, they stay there forever, unless I
> > manually set them all back.
> >
> > Any idea on this?
> >
> 
> Have you checked http://wiki.freebsd.org/TuningPowerConsumption?
> 
> 1. For CX states to function correctly you better disable throttling
> and powerd. I also witnessed at least one machine that hitting any CX
> mode stops generate interrupts on APIC clock (I had to boot it with a
> mousee until I disabled APIC clocks).
> 
> 2. You don't need to set each processor CX value, you only need to
> set:
> 
> hw.acpi.cpu.cx_lowest=C3
> 
> All cpu's will inherit default profile.
> 

First need to see what state the processor supports the current
system
sysctl -a | grep cx_