Android系统 CPU 核数、频率、策略控制

频率、策略控制"/>

Android系统 CPU 核数、频率、策略控制

一、/sys/devices/system/cpu 目录

Z91:/sys/devices/system/cpu # ls -all
ls -all
total 0
drwxr-xr-x 13 root root    0 2018-01-09 11:17 .
drwxr-xr-x  6 root root    0 2018-01-09 11:17 ..
drwxr-xr-x  5 root root    0 2018-01-09 11:17 cpu0 [查看CPU 核数，频率，策略，频率档位]
drwxr-xr-x  5 root root    0 2018-01-10 14:23 cpu1
drwxr-xr-x  5 root root    0 2018-01-10 14:23 cpu2
drwxr-xr-x  5 root root    0 2018-01-10 14:23 cpu3
drwxr-xr-x  3 root root    0 2018-01-09 11:17 cpufreq
drwxr-xr-x  2 root root    0 2018-01-09 11:17 cpuidle
drwxr-xr-x  2 root root    0 2018-01-09 11:17 cputopo
drwxr-xr-x  2 root root    0 2018-01-09 11:17 eas
-r--r--r--  1 root root 4096 2018-01-09 11:17 isolated
-r--r--r--  1 root root 4096 2018-01-09 11:17 kernel_max
-r--r--r--  1 root root 4096 2018-01-09 11:17 modalias
-r--r--r--  1 root root 4096 2018-01-09 11:17 offline
-r--r--r--  1 root root 4096 2018-01-09 11:17 online [查看 CPU 当前开核]
-r--r--r--  1 root root 4096 2018-01-09 11:17 possible
drwxr-xr-x  2 root root    0 2018-01-09 11:17 power
-r--r--r--  1 root root 4096 2018-01-09 11:17 present [查看 CPU 核数]
drwxr-xr-x  2 root root    0 2018-01-09 11:17 rq-stats
drwxr-xr-x  2 root root    0 2018-01-09 11:17 sched
-rw-r--r--  1 root root 4096 2018-01-09 11:17 uevent

二、查看 CPU 核数、频率、策略

2.1 查看 CPU 核数

adb shell cat /sys/devices/system/cpu/present

Z91:/sys/devices/system/cpu # cat present
cat present
0-3

2.2 查看 CPU 当前开核数

adb shell cat /sys/devices/system/cpu/online

Z91:/sys/devices/system/cpu # cat online
cat online
0-3

2.3 查看 CPU 调频档位

adb shell cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies

Z91:/sys/devices/system/cpu/cpu0/cpufreq # cat scaling_available_frequencies
cat scaling_available_frequencies1274000 1235000 1196000 1170000 1105000 1053000 1001000 962000 910000 845000 702
000 624000 546000 416000 338000 299000

2.4 查看 CPU 当前频率

adb shell cat /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_cur_freq

Z91:/sys/devices/system/cpu/cpu0/cpufreq # cat cpuinfo_cur_freq
cat cpuinfo_cur_freq
299000

2.5 查看 CPU 的支持策略

adb shell cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_governors

D:\AndroidStudioProject\CpuRun>adb shell cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_governors
ondemand userspace powersave interactive performance sched

2.6 查看 CPU 的运行策略

adb shell cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor

D:\AndroidStudioProject\CpuRun>adb shell cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
sched

三、设置 CPU 核数、频率、策略

3.1 控制 CPU 核数

3.1.1 开核命令

adb shell “echo 1 > /sys/devices/system/cpu/cpu【index】/online”

adb shell "echo 1 > /sys/devices/system/cpu/cpu1/online"
adb shell "echo 1 > /sys/devices/system/cpu/cpu2/online"
adb shell "echo 1 > /sys/devices/system/cpu/cpu3/online"

3.1.2 关核命令

adb shell “echo 0 > /sys/devices/system/cpu/cpu【index】/online”

adb shell "echo 0 > /sys/devices/system/cpu/cpu1/online"
adb shell "echo 0 > /sys/devices/system/cpu/cpu2/online"
adb shell "echo 0 > /sys/devices/system/cpu/cpu3/online"

3.1.3 查询命令

adb shell cat /sys/devices/system/cpu/cpu【index】/online

查看单个
adb shell cat /sys/devices/system/cpu/cpu1/online
adb shell cat /sys/devices/system/cpu/cpu2/online
adb shell cat /sys/devices/system/cpu/cpu3/online查看全部
adb shell cat /sys/devices/system/cpu/present

3.2 控制 CPU 策略

需要事先查看所支持策略类型

adb shell “echo 【governor策略】 > /sys/devices/system/cpu/cpu【index】/cpufreq/scaling_governor”

adb shell "echo performance > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor"
adb shell "echo ondemand > /sys/devices/system/cpu/cpu1/cpufreq/scaling_governor"
adb shell "echo sched > /sys/devices/system/cpu/cpu2/cpufreq/scaling_governor"
adb shell "echo interactive > /sys/devices/system/cpu/cpu3/cpufreq/scaling_governor"查看修改是否成功
adb shell cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor

3.2 控制 CPU 频率

限制最高频率的阈值或者scaling_setspeed，但是实际设置可能觉得没设置到，其实也是正常的，因为CPU调频和场景相关，比如点开应用和滑动桌面都会频率全开，不受到频率控制，这里走了 CPU 场景调频模式了

adb shell “echo 【频率】 > /sys/devices/system/cpu/cpu【index】/cpufreq/scaling_setspeed”

adb shell “echo 【频率】 > /sys/devices/system/cpu/cpu【index】/cpufreq/cpuinfo_max_freq”

1.查询支持的档位
adb shell cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies1274000 1235000 1196000 1170000 1105000 1053000 1001000 962000 910000 845000 702
000 624000 546000 416000 338000 2990002.查看当前最高频率阈值
adb shell "cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq"
adb shell "cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed"3.设置最高当前最高频率阈值 scaling_setspeed
adb shell "echo 845000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq"
adb shell "echo 845000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed"
adb shell "echo 1274000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq"4.查看当前频率，验证结果
adb shell cat /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_cur_freq