debug.cpufreq.lowest doesn't work?

[Kemian Dang]

Hi all,

I set "sysctl debug.cpufreq.lowest=800" but sysctl -a still told me that 
the CPU freq is at 300, though it will jump high if I am doing some 
heavy work.
This reduce of performance makes me even have trouble on browsing website.
Did I miss something important?

12:29pm kemian ~> sudo sysctl debug.cpufreq.lowest=800
debug.cpufreq.lowest: 0 -> 800

12:32pm kemian ~> sysctl -a | grep freq |grep cpu
debug.cpufreq.verbose: 0
debug.cpufreq.lowest: 800
dev.cpu.0.freq: 300
dev.cpu.0.freq_levels: 1800/35000 1600/28347 1400/24803 1200/21260 
1000/17716 800/8227
dev.cpufreq.0.%driver: cpufreq
dev.cpufreq.0.%parent: cpu0
dev.cpufreq.1.%driver: cpufreq
dev.cpufreq.1.%parent: cpu1


Best wishes,
Kemian