Re: CPU C-state storange on Panasonic TOUGH BOOK CF-R9

Norikatsu Shigemura wrote:
> On Sun, 12 Sep 2010 12:29:37 +0300
> Alexander Motin <mav_at_FreeBSD.org> wrote:
|>> hw.acpi.cpu.cx_lowest has default in C1. Have you tried to rise it via
>> sysctl?
> 
> 	Oops, I forgot usage of cx_lowest.
> - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
> # sysctl hw.acpi.cpu.cx_lowest=C2
> hw.acpi.cpu.cx_lowest: C1 -> C2
> # sysctl -a | grep cx            
> hw.acpi.cpu.cx_lowest: C2
> dev.cpu.0.cx_supported: C1/3 C2/245
> dev.cpu.0.cx_lowest: C2
> dev.cpu.0.cx_usage: 19.34% 80.65% last 49us
> dev.cpu.1.cx_supported: C1/3 C2/245
> dev.cpu.1.cx_lowest: C2
> dev.cpu.1.cx_usage: 15.28% 84.71% last 922us
> dev.cpu.2.cx_supported: C1/3 C2/245
> dev.cpu.2.cx_lowest: C2
> dev.cpu.2.cx_usage: 77.90% 22.09% last 6034us
> dev.cpu.3.cx_supported: C1/3 C2/245
> dev.cpu.3.cx_lowest: C2
> dev.cpu.3.cx_usage: 80.28% 19.71% last 398us
> - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

`sysctl -a` is a bad tool to estimate C-states usage. It causes a lot of
context switches, making data dirty. To get more precise data, try:

sysctl hw.acpi.cpu.cx_lowest=C2 && sleep 10 && sysctl dev.cpu.0.cx_usage
dev.cpu.1.cx_usage dev.cpu.2.cx_usage dev.cpu.3.cx_usage

-- 
Alexander Motin