Android系统 固定住CPU频率

1. 切换 CPU 策略为 userspcace

adb shell “echo userspace > /sys/devices/system/cpu/cpu【Index】/cpufreq/scaling_governor”

这里起到固定频率的作用

userspace 最早的 cpufreq 子系统通过 userspace governor 为用户提供了这种灵活性。系统将变频策略的决策权交给了用户态应用程序，并提供了相应的接口供用户态应用程序调节CPU 运行频率使用。（可以使用 Dominik 等人开发了 cpufrequtils 工具包 ）

示例
================================================================================
设置前查看当前支持的策略
D:\PythonProject\python3-webapp-Su\www>adb shell cat "/sys/devices/system/cpu/cpu0/cpufreq/scaling_governor"
sched

Z91:/sys/devices/system/cpu/cpu0/cpufreq # cat scaling_available_governors
cat scaling_available_governors
ondemand userspace powersave interactive performance sched

================================================================================
设置- userspcace 策略
D:\PythonProject\python3-webapp-Su\www>adb shell "echo userspace > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor"

================================================================================
设置后查看
D:\PythonProject\python3-webapp-Su\www>adb shell cat "/sys/devices/system/cpu/cpu0/cpufreq/scaling_governor"
userspace

2. 设置频率

adb shell “echo [频率档位] > /sys/devices/system/cpu/cpu【Index】/cpufreq/scaling_setspeed”

adb shell “echo 910000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed”

示例
================================================================================
设置前查看频率档次
Z91:/sys/devices/system/cpu/cpu0/cpufreq # cat scaling_available_frequencies
cat scaling_available_frequencies
1274000 1235000 1196000 1170000 1105000 1053000 1001000 962000 910000 845000 702
000 624000 546000 416000 338000 299000

D:\PythonProject\python3-webapp-Su\www>adb shell "cat /sys/devices/system/cpu/cp
u0/cpufreq/scaling_setspeed"
1274000
================================================================================
设置频率
D:\PythonProject\python3-webapp-Su\www>adb shell "echo 910000 > /sys/devices/sys
tem/cpu/cpu0/cpufreq/scaling_setspeed"

================================================================================
设置后查看
D:\PythonProject\python3-webapp-Su\www>adb shell "cat /sys/devices/system/cpu/cp
u0/cpufreq/scaling_setspeed"
910000

3.验证

查看当前频率

adb shell “cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq”

Z91:/sys/devices/system/cpu/cpu0/cpufreq # cat scaling_cur_freq
cat scaling_cur_freq
910000
Z91:/sys/devices/system/cpu/cpu0/cpufreq # cat scaling_cur_freq
cat scaling_cur_freq
910000
Z91:/sys/devices/system/cpu/cpu0/cpufreq # cat scaling_cur_freq
cat scaling_cur_freq
910000
Z91:/sys/devices/system/cpu/cpu0/cpufreq # cat scaling_cur_freq
cat scaling_cur_freq
910000
Z91:/sys/devices/system/cpu/cpu0/cpufreq # cat scaling_cur_freq
cat scaling_cur_freq
910000
Z91:/sys/devices/system/cpu/cpu0/cpufreq # cat scaling_cur_freq
cat scaling_cur_freq
910000
Z91:/sys/devices/system/cpu/cpu0/cpufreq # cat scaling_cur_freq
cat scaling_cur_freq
910000
Z91:/sys/devices/system/cpu/cpu0/cpufreq # cat scaling_cur_freq
cat scaling_cur_freq
910000
Z91:/sys/devices/system/cpu/cpu0/cpufreq # cat scaling_cur_freq
cat scaling_cur_freq
910000

adb shell “cat /sys/devices/system/cpu/cpu0/cpufreq/stats/trans_table”

Z91:/sys/devices/system/cpu/cpu0/cpufreq/stats # cat trans_table
cat trans_table
From  :    To
:   1274000   1235000   1196000   1170000   1105000   1053000   1001000
962000    910000    845000    702000    624000    546000    416000    338000
299000
1274000:         0     72086     30152     45166     26802     22756     12876
14665     15069     19964      9916      7919      9179      5340      2574
40418
1235000:    157400         0      5901      4770      2327      2112      2596
2698      2500      3182      1094       688       505       364       127
3543
1196000:     34936     67770         0      6519      1791      1316       955
1945      1560      2324       899       526       380       201        86
1778
1170000:     40951     26632     67810         0      7262      3694      2242
4277      5075      6946      2082      1148       936       583       204
3856
1105000:     16596      8787      9777     75941         0      5691      2241
2475      5080      7311      2249      1169       856       480       201
3011
1053000:     12324      2572      3135     22246     71408         0      5509
4314      3505     11277      3786      1989      1446       625       266
2640
1001000:      7200      1604       908      5496     14872     67595         0
5141      3611      7775      4061      2273      1492       512       198
2607
962000:      8339      1831      1061      3513      7956     25683     68943
0      7431     14108      9196      5912      4174      1179       490
3578
910000:      7886      1503       956      2602      3442      9306     16914
78332         0     15817      8116      6036      4673      1071       414
4904
845000:     12534      1354       928      2215      2172      5106      9893
44259    102265         0     20634     27991     44054     11631      2671
19834
702000:      8385       698       453       929       602       789      1002
2361     10980    129393         0     12538     37133     17373      4490
22439
624000:      5710       464       254       695       772       971       776
874      1531     34078     93861         0     20684     19690      5655
35303
546000:      5514       361       205       439       378       380       248
420       763     46006     66027     30107         0     22667      9997
41643
416000:      3629       494       379      1233      1080       735       407
536       827      3219     22281    113398     28840         0     12555
131669
338000:       610       119        50        86        47        65        49
63       136       521       582      3063     34551     11133         0
16250
299000:     12868      3532      1017      1848       954       843       694
1033      1640      5620      4781      6561     36252    228433     27397
0
Z91:/sys/devices/system/cpu/cpu0/cpufreq/stats #