使用系统命令top即可看到如下类似信息：

Cpu(s):  0.0%us,  0.5%sy,  0.0%ni, 99.5%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st

但不知什么含义？google之

中文翻译为：
si 软件中断 

I try to explain  these:
us: is meaning of "user CPU time"
sy: is meaning of "system CPU time"
ni: is meaning of" nice CPU time"
id: is meaning of "idle"
wa: is meaning of "iowait" 
hi：is meaning of "hardware irq"
si : is meaning of "software irq"
st : is meaning of "steal time"

us 用户空间占用CPU百分比
sy 内核空间占用CPU百分比
ni 用户进程空间内改变过优先级的进程占用CPU百分比
id 空闲CPU百分比
wa 等待输入输出的CPU时间百分比
hi 硬件中断
si 软件中断