linux dfs 參數

路徑為/sys/devices/system/cpu/cpu0/cpufreq/

有下列檔案:
./cpuinfo_min_freq(CPU最小頻率)
./cpuinfo_max_freq(CPU最大頻率)
./scaling_min_freq(DFS最小頻率)
./scaling_max_freq(DFS最大頻率)
./affected_cpus
./related_cpus
./scaling_governor(設定DFS方法)
./scaling_driver
./scaling_available_governors(顯示DFS方法)
./scaling_setspeed(設定CPU頻率)
./scaling_cur_freq(顯示目前CPU頻率)
./stats
./stats/total_trans
./stats/time_in_state
./stats/trans_table
./ondemand(若scaling_governor設為ondemand則會用到此資料夾的參數)
./ondemand/sampling_rate_max(最大取樣頻率)
./ondemand/sampling_rate_min(最小取樣頻率)
./ondemand/sampling_rate(設定取樣頻率)
./ondemand/up_threshold(CPU使用率大於此值則升頻)
./ondemand/down_differential(CPU使用率小於此值則降頻)
./ondemand/ignore_nice_load
./ondemand/powersave_bias(下面詳細解釋)


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in /sys/devices/system/cpu/cpu0/cpufreq/ondemand/powersave_bias

說明
http://osdir.com/ml/kernel.cpufreq/2006-07/msg00137.html


這個值的範圍為0-1000，代表0.1%-100%

假設現在系統要切到2GHz

若powersave_bias設為100(10%)，
則這次會先跳到1.8G(比預期目標少10%)