4，字段含义如下
　　英文解释：
　　CPU：Processor number. The keyword all indicates that statistics are calculated as averages among all processors.
　　%user：Show the percentage of CPU utilization that occurred while executing at the user level (application).
　　%nice：Show the percentage of CPU utilization that occurred while executing at the user level with nice priority.
　　%sys：Show  the  percentage  of CPU utilization that occurred while executing at the system level (kernel). Note that
　　this does not include time spent servicing interrupts or softirqs.
　　%iowait：Show the percentage of time that the CPU or CPUs were idle during which the system had an outstanding disk  I/O request.
　　%irq：Show the percentage of time spent by the CPU or CPUs to service interrupts.
　　%soft：Show  the  percentage  of time spent by the CPU or CPUs to service softirqs.  A softirq (software interrupt) is
　　one of up to 32 enumerated software interrupts which can run on multiple CPUs at once.
　　%steal：Show the percentage of time spent in involuntary wait by the virtual CPU or CPUs while the hypervisor was  ser-vicing another virtual processor.
　　%idle：Show  the percentage of time that the CPU or CPUs were idle and the system did not have an outstanding disk I/O request.
　　intr/s：Show the total number of interrupts received per second by the CPU or CPUs.
　　参数解释 从/proc/stat获得数据
　　CPU 处理器 ID
　　user 在internal时间段里，用户态的CPU时间（%），不包含 nice值为负 进程 (usr/total)*100
　　nice 在internal时间段里，nice值为负进程的CPU时间（%）   (nice/total)*100
　　system 在internal时间段里，核心时间（%）   (system/total)*100
　　iowait 在internal时间段里，硬盘IO等待时间（%） (iowait/total)*100
　　irq 在internal时间段里，硬中断时间（%）      (irq/total)*100
　　soft 在internal时间段里，软中断时间（%）    (softirq/total)*100
　　idle 在internal时间段里，CPU除去等待磁盘IO操作外的因为任何原因而空闲的时间闲置时间（%）(idle/total)*100
　　intr/s 在internal时间段里，每秒CPU接收的中断的次数intr/total)*100
　　CPU总的工作时间=total_cur=user+system+nice+idle+iowait+irq+softirq
　　total_pre=pre_user+ pre_system+ pre_nice+ pre_idle+ pre_iowait+ pre_irq+ pre_softirq
　　user=user_cur – user_pre
　　total=total_cur-total_pre
　　其中_cur 表示当前值，_pre表示interval时间前的值。上表中的所有值可取到两位小数点。