初试：优化高通cpu在MIUI上的配置
前言
当前手机硬件日新月异，在某种程度上手机硬件性能已经过剩，手机的性能反而在于软件上的优化。比如小米4搭载的高通801这款cpu四核2.5GHZ,性能已经不错，但是由于MIUI对cpu进行无脑的限频，均衡模式下，关闭两个核心，其他两个核心频率限制在1036MHz,1036MHz!这样无异于杀鸡用牛刀，而且用的是刀柄，连鸡都搞不定。估计把性能压得如此底，厂商也有自己的考虑吧。
正题
下面介绍要修改的cpu配置文件的含义
主要文件有
1、thermal-engine-8974.conf（system/etc目录下 ）
2、changepowermode.sh（system/bin目录下）
####1、thermal-engine-8974.conf
用于设定cpu在指定条件下触发的动作的算法
其中各个属性含义：
sampling:取样时间
[CPU_MONITOR]：算法实例标签
algo_type:算法类型,共有4种： monitor, pid, ss, virtual
sensor:传感器
thresholds: 觉阈值（触发条件）
thresholds_clr:清除觉阈值（取消触发的动作的条件）
actions:动作
action_info:动作值
###changepowermode.sh
顾名思义，这个文件就是MIUI切换均衡模式和性能模式的命令文件。
target=`getprop ro.product.model`
powermode=`getprop persist.sys.aries.power_profile`
dev_governor=`ls /sys/class/devfreq/qcom,cpubw*/governor`
case "$target" in
"MI 3W" | "MI 3C")
case "$powermode" in
"high")
echo 2265600 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
echo 2265600 > /sys/devices/system/cpu/cpu1/cpufreq/scaling_max_freq
echo 2265600 > /sys/devices/system/cpu/cpu2/cpufreq/scaling_max_freq
echo 2265600 > /sys/devices/system/cpu/cpu3/cpufreq/scaling_max_freq
echo 20000 > /sys/devices/system/cpu/cpufreq/interactive/above_hispeed_delay
echo 60 > /sys/devices/system/cpu/cpufreq/interactive/go_hispeed_load
echo 1190400 > /sys/devices/system/cpu/cpufreq/interactive/hispeed_freq
echo 70 > /sys/devices/system/cpu/cpufreq/interactive/target_loads
echo 40000 > /sys/devices/system/cpu/cpufreq/interactive/min_sample_time
echo 20 > /sys/module/cpu_boost/parameters/boost_ms
echo 1728000 > /sys/module/cpu_boost/parameters/sync_threshold
echo 1497600 > /sys/module/cpu_boost/parameters/input_boost_freq
echo 40 > /sys/module/cpu_boost/parameters/input_boost_ms
echo 255 > /sys/class/leds/lcd-backlight/max_brightness
echo 578000000 > /sys/class/kgsl/kgsl-3d0/max_gpuclk
echo "msm_cpufreq" > $dev_governor
;;
"middle")
echo 2265600 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
echo 2265600 > /sys/devices/system/cpu/cpu1/cpufreq/scaling_max_freq
echo 2265600 > /sys/devices/system/cpu/cpu2/cpufreq/scaling_max_freq
echo 2265600 > /sys/devices/system/cpu/cpu3/cpufreq/scaling_max_freq
echo "20000 1400000:40000 1700000:20000" > /sys/devices/system/cpu/cpufreq/interactive/above_hispeed_delay
echo 90 > /sys/devices/system/cpu/cpufreq/interactive/go_hispeed_load
echo 1190400 > /sys/devices/system/cpu/cpufreq/interactive/hispeed_freq
echo "85 1500000:90 1800000:70" > /sys/devices/system/cpu/cpufreq/interactive/target_loads
echo 40000 > /sys/devices/system/cpu/cpufreq/interactive/min_sample_time
echo 20 > /sys/module/cpu_boost/parameters/boost_ms
echo 1728000 > /sys/module/cpu_boost/parameters/sync_threshold
echo 1190400 > /sys/module/cpu_boost/parameters/input_boost_freq
echo 40 > /sys/module/cpu_boost/parameters/input_boost_ms
echo 255 > /sys/class/leds/lcd-backlight/max_brightness
echo 578000000 > /sys/class/kgsl/kgsl-3d0/max_gpuclk
echo "cpubw_hwmon" > $dev_governor
;;
"low")
echo 1036800 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
echo 1036800 > /sys/devices/system/cpu/cpu1/cpufreq/scaling_max_freq
echo 1036800 > /sys/devices/system/cpu/cpu2/cpufreq/scaling_max_freq
echo 1036800 > /sys/devices/system/cpu/cpu3/cpufreq/scaling_max_freq
echo "40000" > /sys/devices/system/cpu/cpufreq/interactive/above_hispeed_delay
echo 90 > /sys/devices/system/cpu/cpufreq/interactive/go_hispeed_load
echo 960000 > /sys/devices/system/cpu/cpufreq/interactive/hispeed_freq
echo "85 960000:70" > /sys/devices/system/cpu/cpufreq/interactive/target_loads
echo 40000 > /sys/devices/system/cpu/cpufreq/interactive/min_sample_time
echo 0 > /sys/module/cpu_boost/parameters/boost_ms
echo 960000 > /sys/module/cpu_boost/parameters/sync_threshold
echo 960000 > /sys/module/cpu_boost/parameters/input_boost_freq
echo 40 > /sys/module/cpu_boost/parameters/input_boost_ms
echo 100 > /sys/class/leds/lcd-backlight/max_brightness
echo 330000000 > /sys/class/kgsl/kgsl-3d0/max_gpuclk
echo "cpubw_hwmon" > $dev_governor
;;
esac
;;
"LEO "* | "MI 4"* | "MI NOTE"* | "VIRGO"*)
case "$powermode" in
"high")
stop mpdecision
sleep 1
echo 1 > /sys/devices/system/cpu/cpu1/online
echo 1 > /sys/devices/system/cpu/cpu2/online
echo 1 > /sys/devices/system/cpu/cpu3/online
echo 1 > /sys/devices/system/cpu/cpu1/online
echo 1 > /sys/devices/system/cpu/cpu2/online
echo 1 > /sys/devices/system/cpu/cpu3/online
echo 2457600 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
echo 2457600 > /sys/devices/system/cpu/cpu1/cpufreq/scaling_max_freq
echo 2457600 > /sys/devices/system/cpu/cpu2/cpufreq/scaling_max_freq
echo 2457600 > /sys/devices/system/cpu/cpu3/cpufreq/scaling_max_freq
echo performance > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
echo performance > /sys/devices/system/cpu/cpu1/cpufreq/scaling_governor
echo performance > /sys/devices/system/cpu/cpu2/cpufreq/scaling_governor
echo performance > /sys/devices/system/cpu/cpu3/cpufreq/scaling_governor
echo 20 > /sys/module/cpu_boost/parameters/boost_ms
echo 1728000 > /sys/module/cpu_boost/parameters/sync_threshold
echo 1497600 > /sys/module/cpu_boost/parameters/input_boost_freq
echo 40 > /sys/module/cpu_boost/parameters/input_boost_ms
echo 255 > /sys/class/leds/lcd-backlight/max_brightness
echo 578000000 > /sys/class/kgsl/kgsl-3d0/max_gpuclk
echo performance > /sys/class/kgsl/kgsl-3d0/devfreq/governor
echo "msm_cpufreq" > $dev_governor
;;
"middle")
echo interactive > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
echo interactive > /sys/devices/system/cpu/cpu1/cpufreq/scaling_governor
echo interactive > /sys/devices/system/cpu/cpu2/cpufreq/scaling_governor
echo interactive > /sys/devices/system/cpu/cpu3/cpufreq/scaling_governor
echo 2457600 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
echo 2457600 > /sys/devices/system/cpu/cpu1/cpufreq/scaling_max_freq
echo 2457600 > /sys/devices/system/cpu/cpu2/cpufreq/scaling_max_freq
echo 2457600 > /sys/devices/system/cpu/cpu3/cpufreq/scaling_max_freq
echo "20000 1400000:40000 1700000:20000" > /sys/devices/system/cpu/cpufreq/interactive/above_hispeed_delay
echo 90 > /sys/devices/system/cpu/cpufreq/interactive/go_hispeed_load
echo 1190400 > /sys/devices/system/cpu/cpufreq/interactive/hispeed_freq
echo "85 1500000:99" > /sys/devices/system/cpu/cpufreq/interactive/target_loads
echo 40000 > /sys/devices/system/cpu/cpufreq/interactive/min_sample_time
echo 20 > /sys/module/cpu_boost/parameters/boost_ms
echo 1497600 > /sys/module/cpu_boost/parameters/sync_threshold
echo 1190400 > /sys/module/cpu_boost/parameters/input_boost_freq
echo 40 > /sys/module/cpu_boost/parameters/input_boost_ms
echo 255 > /sys/class/leds/lcd-backlight/max_brightness
echo 578000000 > /sys/class/kgsl/kgsl-3d0/max_gpuclk
echo msm-adreno-tz > /sys/class/kgsl/kgsl-3d0/devfreq/governor
echo "cpubw_hwmon" > $dev_governor
start mpdecision
;;
esac
;;
esac
可以看到 "LEO "* | “MI 4”* | “MI NOTE”* | “VIRGO”*)
case “$powermode” in
“high”)
的部分，这是性能模式下的调节文件。
“middle”，是均衡模式的部分。
####根据changepowermode的内容，可知里面各个文件的主要功能：
1、/sys/devices/system/cpu/cpuX/cpufreq/scaling_governor
用于控制cpu0的运行模式
运行模式有6种：interactive,conservative,ondemand,userspace,powersave,performance
2、/sys/devices/system/cpu/cpuX/cpufreq/scaling_max_freq
用于控制cpu的最大频率，频率从300000~2457600（此为801的范围，其他型号各异）。系统就是通过这个文件来限频，修改此文件可以修改cpu最高频率。
3、/sys/devices/system/cpu/cpufreq/interactive/ 下的文件
above_hispeed_delay：跳到高频要花的时间（微妙）
go_hispeed_load：是高频阈值。当系统的负载超过该值，升频，否则降频。具体如何升频、如何降频，后面介绍。
hispeed_freq：高速状态的频率
target_loads：CPU的负载达到设定百分比时进入预设的频率
min_sample_time：下调频率的最小时间. 该值设置的越高, CPU降频越慢. 单位uS, 例如80000=80ms
target_loads: 一般情况下, 调速器根据target_loads参数调整频率, 负载超过设定值时提高频率, 反之则下降频率. 该值设置的越低, CPU越容易提升频率. 单位:%, 频率单位:KHz
above_hispeed_delay：当核心保持hispeed_freq超过一定时间(above_hispeed_delay), 且负载依然很高, CPU频率才会继续上升.
4、 /sys/module/cpu_boost/parameters/
boost_ms：加速时间
sync_threshold：同步阈值
input_boost_freq：检测到输入时加速的频率
input_boost_ms：检测到输入时的加速时间
5、除了以上文件，我还发现了对防止被系统反复修改为限频的两个很重要的文件，分别是/sys/devices/system/cpu/cpuX/cpufreq/sys_cap_freq和/sys/devices/system/cpu/cpu0/cpufreq/thermal_capp_freq。
sys_cap_freq：意为系统覆盖频率，调了一下里面的参数，发现如果从性能模式返回均衡模式，限频的就是这个参数
thermal_capp_freq：这个是性能模式的参数，同理。
###注意：修改文件需要使用RE管理器和获取root。
通过修改上面的参数，解除限频。经过测试，为了避免参数被系统修改，需要关闭MIUI的神隐模式。
以下是我自用的修改后的截图，较为激进，当然，保守的也可以自行修改。
thermal-engine-8974.conf
sampling 5000
[CPU0_MONITOR]
algo_type monitor
sensor cpu0
sampling 1000
thresholds 55000 60000 65000 70000 85000 105000 115000
thresholds_clr 50000 55000 60000 66000 80000 90000 110000
actions cpu cpu cpu cpu cpu cpu shutdown
action_info 2457600 2457600 2457600 2457600 1728000 1036800 0
[CPU1_MONITOR]
algo_type monitor
sensor cpu1
sampling 65
thresholds 115000
thresholds_clr 110000
actions shutdown
action_info 0
[CPU2_MONITOR]
algo_type monitor
sensor cpu2
sampling 65
thresholds 115000
thresholds_clr 110000
actions shutdown
action_info 0
[CPU3_MONITOR]
algo_type monitor
sensor cpu3
sampling 65
thresholds 115000
thresholds_clr 110000
actions shutdown
action_info 0
[BATTERY_MONITOR]
algo_type monitor
sensor batt_temp
sampling 1000
thresholds 380 395 500 550
thresholds_clr 370 385 450 500
actions cpu cpu cpu cpu
action_info 2457600 2457600 2457600 2457600
/sys/devices/system/cpu/cpuX/cpufreq/scaling_max_freq
2457600
/sys/devices/system/cpu/cpuX/cpufreq/sys_cap_freq
2457600
其他文件的保持不变。
性能监视器下截图：
完毕。