acpi cpu throttling

[Nate Lawson]

rejden wrote:
> Hi,
> is there any way how to change CPU frequency with ACPI ?
> i saw something similar under linux, googling whole night and nothin...
> i'm running generic 5.3release kernel
> 
> jan
> 
> -----
> 
> daemon# sysctl -a |grep cpu
> kern.threads.virtual_cpu: 1
> kern.ccpu: 1948
> kern.smp.maxcpus: 1
> kern.smp.cpus: 1
> hw.ncpu: 1
> hw.acpi.cpu.throttle_max: 8
> hw.acpi.cpu.throttle_state: 8
> hw.acpi.cpu.cx_supported: C1/1 C2/2 C3/185
> hw.acpi.cpu.cx_lowest: C3
> hw.acpi.cpu.cx_usage: 0.08% 99.91% 0.00%
> machdep.cpu_idle_hlt: 1
> dev.cpu.0.%desc: ACPI CPU (3 Cx states)
> dev.cpu.0.%driver: cpu
> dev.cpu.0.%location: handle=\_PR_.CPU0
> dev.cpu.0.%pnpinfo: _HID=none _UID=0
> dev.cpu.0.%parent: acpi0
> 
> daemon# dmesg -a |grep cpu
> cpu0: <ACPI CPU (3 Cx states)> on acpi0
> acpi_cpu: throttling enabled, 8 steps (100% to 12.5%), currently 100.0%
> hw.acpi.cpu.cx_lowest: 
> hw.acpi.cpu.throttle_state: 

You can set it directly with sysctl hw.acpi.cpu.throttle_state. 
However, you will probably find using /etc/rc.conf more useful.  There, 
you can set the online and offline Cx and throttling levels.  See 
/etc/defaults/rc.conf for info.

-Nate