choose_freq分析

最新推荐文章于 2021-05-19 22:00:52 发布

cainiao413

最新推荐文章于 2021-05-19 22:00:52 发布

阅读量363

点赞数

CC 4.0 BY-SA版权

分类专栏： linux/android

本文链接：https://blog.youkuaiyun.com/cainiao413/article/details/45621671

linux/android 专栏收录该内容

37 篇文章

订阅专栏

本文详细解析了CPU频率调节过程中的关键步骤，包括选择频率、调整负载和目标频率的确定，以及循环迭代的过程。通过具体例子展示了如何在不同负载条件下进行频率调整。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

choose_freq分析
1 800000:85 998400:90 1094400:80 1190400:80 1248000:80 1305600:80
例子1： loadadjfreq=cpu_load*pcpu->policy->cur=92*998400
循环1：
   prevfreq = freq=998400；
   tl=90（998400:90）通过当前频率找到下一级load
   loadadjfreq / tl=1020500
cpufreq_frequency_table_target: start
    target_freq=1020500
    CPUFREQ_RELATION_L
    freq=800,suboptimal.frequency = 800 suboptimal.driver_data=0;
    freq=998.4,suboptimal.frequency = 998.4 suboptimal.driver_data=1;
    freq=1094400,optimal.frequency = 1094400 optimal.driver_data=2
    freq=1190400 1248000 1305600（不起作用） optimal.frequency = 1094400 i=5
    *index = optimal.driver_data=2;
cpufreq_frequency_table_target: end
    freq=1094400
    freqmin = prevfreq=998400;
   freqmax = UINT_MAX;

while (freq != prevfreq)进入循环2：
   prevfreq = freq=1094400；
   tl=80（1094400:80）通过当前频率找到下一级load
   loadadjfreq / tl=92*998400/80=1148160
cpufreq_frequency_table_target: start
    target_freq=1148160
    CPUFREQ_RELATION_L
    freq=800,suboptimal.frequency = 800 suboptimal.driver_data=0;
    freq=998.4,suboptimal.frequency = 998.4 suboptimal.driver_data=1;
    freq=1094400,optimal.frequency = 1094400 optimal.driver_data=2
    freq=1190400 1248000 1305600（不起作用） optimal.frequency = 1094400 i=5
    *index = optimal.driver_data=2;
cpufreq_frequency_table_target: end
    freq=1094400
    freqmin = prevfreq=1094400;
   freqmax = UINT_MAX;
while (freq != prevfreq)跳出循环

例子2： loadadjfreq=cpu_load*pcpu->policy->cur=60*1190400

1 800000:85 998400:90 1094400:80 1190400:80 1248000:80 1305600:80

循环1：
   prevfreq = freq=1190400；
   tl=80（1190400:80）通过当前频率找到下一级load
   loadadjfreq / tl=892800
cpufreq_frequency_table_target: start
    target_freq=892800
    CPUFREQ_RELATION_L
    freq=800,suboptimal.frequency = 800 suboptimal.driver_data=0;
    freq=998.4,optimal.frequency = 998.4 suboptimal.driver_data=1;
    freq=1094400 1190400 1248000 1305600（不起作用） optimal.frequency = 1094400 i=5
    *index = optimal.driver_data=1;
cpufreq_frequency_table_target: end
    freq=998.400
    freqmax = prevfreq=1190400;   freqmin = 0;
   freqmax = UINT_MAX;

while (freq != prevfreq)进入循环2：

   prevfreq = freq=998.400；
   tl=90（998400:90）通过当前频率找到下一级load
   loadadjfreq / tl=60*1190400/90=793600
cpufreq_frequency_table_target: start
    target_freq=793600
    CPUFREQ_RELATION_L
    freq=800000,optimal.frequency = 800 optimal.driver_data=0;
    freq=***1190400 1248000 1305600（不起作用） optimal.frequency = 1094400 i=5
    *index = optimal.driver_data=0;
cpufreq_frequency_table_target: end
    freq=800000
    freqmin = 0;
    freqmax = 998400;

while (freq != prevfreq)进入循环3：

   prevfreq = freq=800000；
   tl=85（800000:85）通过当前频率找到下一级load
   loadadjfreq / tl=60*1190400/85=840.282
cpufreq_frequency_table_target: start
    target_freq=840.282
    CPUFREQ_RELATION_L
    freq=800,suboptimal.frequency = 800 suboptimal.driver_data=0;
    freq=998.400,optimal.frequency = 998.400 suboptimal.driver_data=1;
    freq=1094400 1190400 1248000 1305600（不起作用） optimal.frequency = 1094400 i=5
    *index = optimal.driver_data=1;
cpufreq_frequency_table_target: end
    freq=998.400
    freqmin = prevfreq = 800000;
    freqmax = 998400;
    进入if (freq >= freqmax)
cpufreq_frequency_table_target: start
    target_freq=freqmax-1=998339
    CPUFREQ_RELATION_H
    freq=800.000,optimal.frequency = 800.000 optimal.driver_data =0;
    freq=998.4,suboptimal.frequency = 998.4 suboptimal.driver_data=1;
    freq=1094400 1190400 1248000 1305600（不起作用） suboptimal.frequency = 1094400 i=5
    *index = optimal.driver_data=0;
cpufreq_frequency_table_target: end
    freq=800000
    freqmin = 800000;
    freq=freqmax = 998400;
跳出循环