通过gopsutil获取进程CPU问题

服务器配置： Ubuntu18.04 4核16g 有一个Java web应用，想通过gopsutil获取该进程的CPU使用率, 默认不访问，通过top查看，CPU使用率浮动0.0~0.3 ``` $ top -p 2439 top - 08:28:20 up 28 days, 19:40, 7 users, load average: 2.67, 1.89, 1.88 Tasks: 1 total, 0 running, 1 sleeping, 0 stopped, 0 zombie %Cpu(s): 25.0 us, 11.4 sy, 0.0 ni, 62.9 id, 0.2 wa, 0.0 hi, 0.6 si, 0.0 st KiB Mem : 16342280 total, 1349456 free, 7832528 used, 7160296 buff/cache KiB Swap: 0 total, 0 free, 0 used. 9406588 avail Mem PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 2439 jiangyd 20 0 7909440 557120 19156 S 0.3 3.4 26:56.50 java ``` go 代码 ``` package main import ( "fmt" "time" "github.com/shirou/gopsutil/process" ) func main() { proce, err := process.NewProcess(2439) if err != nil { fmt.Println(err) } for { t, err := proce.CPUPercent() if err != nil { fmt.Println(err) } fmt.Println(t) time.Sleep(time.Second * 3) } } ``` 通过程序运行获取 （不知道为什么，获取的值都几乎一致） ``` $ go run process.go 0.38034758398948637 0.38034488210257517 0.3803421970541274 0.38033949538827044 0.3803391630394106 0.380338813923693 0.3803361117440858 0.3803334268939177 ``` 以上在Java应用，没有请求的时候，看不出top获取的CPU，与gopsutil 获取进程的CPU有什么区别 现在给Java应用一些压测，例如使用jmeter 100个并发请求，再次通过top查看,cpu使用率的波动在30~50差不多 ``` $ top -p 2439 top - 08:34:42 up 28 days, 19:46, 7 users, load average: 2.14, 2.62, 2.27 Tasks: 1 total, 0 running, 1 sleeping, 0 stopped, 0 zombie %Cpu(s): 31.7 us, 13.5 sy, 0.0 ni, 53.0 id, 0.2 wa, 0.0 hi, 1.6 si, 0.0 st KiB Mem : 16342280 total, 1308800 free, 7845908 used, 7187572 buff/cache KiB Swap: 0 total, 0 free, 0 used. 9384580 avail Mem PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 2439 jiangyd 20 0 7909440 555664 19156 S 45.3 3.4 27:00.33 java ``` 但是再次，通过go 程序去查看，发现与之前一样的值，这里就搞不清了，难道这个CPUPercent 方法错误？ https://godoc.org/github.com/shirou/gopsutil/process#Process.CPUPercent ``` $ go run process.go 0.38471095821959816 0.3849856685762762 0.3853356280277827 0.3856385425690914 0.38586386464412914 0.3860844987718504 0.3863779971000666 0.3866973701931095 ``` 请各位大佬指点迷津啥情况