建站
咨詢
售后
建站咨詢
新聞中心
/proc/stat 文件內(nèi)容：
創(chuàng)新互聯(lián)-專業(yè)網(wǎng)站定制、快速模板網(wǎng)站建設(shè)、高性價(jià)比遷西網(wǎng)站開(kāi)發(fā)、企業(yè)建站全套包干低至880元,成熟完善的模板庫(kù),直接使用。一站式遷西網(wǎng)站制作公司更省心,省錢,快速模板網(wǎng)站建設(shè)找我們，業(yè)務(wù)覆蓋遷西地區(qū)。費(fèi)用合理售后完善，十余年實(shí)體公司更值得信賴。
- [root@Shentar ~]# cat /proc/stat
- cpu 602 0 2164 11445 2294 0 17 0 0
- cpu0 306 0 1232 4553 2125 0 15 0 0
- cpu1 295 0 932 6891 169 0 1 0 0
- intr 7110 269 7 0 1 1 0 5 0 1 0 0 0 91 0 0 106 0 6521 0 108 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
- ctxt 38984
- btime 1368275792
- processes 2713
- procs_running 1
- procs_blocked 0
- [root@Shentar ~]#
***行的數(shù)值表示的是CPU總的使用情況，所以我們只要用***行的數(shù)字計(jì)算就可以了。下表解析***行各數(shù)值的含義：
參數(shù) 解析（單位：jiffies）
(jiffies是內(nèi)核中的一個(gè)全局變量，用來(lái)記錄自系統(tǒng)啟動(dòng)一來(lái)產(chǎn)生的節(jié)拍數(shù)，在linux中，一個(gè)節(jié)拍大致可理解為操作系統(tǒng)進(jìn)程調(diào)度的最小時(shí)間片，不同linux內(nèi)核可能值有不同，通常在1ms到10ms之間)
user (38082) 從系統(tǒng)啟動(dòng)開(kāi)始累計(jì)到當(dāng)前時(shí)刻，處于用戶態(tài)的運(yùn)行時(shí)間，不包含 nice值為負(fù)進(jìn)程。
nice (627) 從系統(tǒng)啟動(dòng)開(kāi)始累計(jì)到當(dāng)前時(shí)刻，nice值為負(fù)的進(jìn)程所占用的CPU時(shí)間
system (27594) 從系統(tǒng)啟動(dòng)開(kāi)始累計(jì)到當(dāng)前時(shí)刻，處于核心態(tài)的運(yùn)行時(shí)間
idle (893908) 從系統(tǒng)啟動(dòng)開(kāi)始累計(jì)到當(dāng)前時(shí)刻，除IO等待時(shí)間以外的其它等待時(shí)間iowait (12256) 從系統(tǒng)啟動(dòng)開(kāi)始累計(jì)到當(dāng)前時(shí)刻，IO等待時(shí)間(since 2.5.41)
irq (581) 從系統(tǒng)啟動(dòng)開(kāi)始累計(jì)到當(dāng)前時(shí)刻，硬中斷時(shí)間(since 2.6.0-test4)
softirq (895) 從系統(tǒng)啟動(dòng)開(kāi)始累計(jì)到當(dāng)前時(shí)刻，軟中斷時(shí)間(since 2.6.0-test4)stealstolen(0) which is the time spent in other operating systems when running in a virtualized environment(since 2.6.11)
guest(0) which is the time spent running a virtual CPU for guest operating systems under the control of the Linux kernel(since 2.6.24)
結(jié)論：總的cpu時(shí)間totalCpuTime = user + nice + system + idle + iowait + irq + softirq + stealstolen + guest
計(jì)算時(shí)，采樣兩個(gè)時(shí)間點(diǎn)的數(shù)據(jù)，對(duì)于時(shí)間點(diǎn)1，記錄總的cpu時(shí)間total1，記錄空閑時(shí)間idle1，對(duì)于時(shí)間2，同樣記錄total2和idle2。
菜譜使用率為：cpuusage = 1 – (idle2 – idle1) / (total2 – total1)
注意，如果時(shí)間點(diǎn)1和時(shí)間點(diǎn)2間隔足夠小（小于10ms），則可能出現(xiàn)total2 – total1為0，這樣cpu使用率應(yīng)該為0，而不是采用除法計(jì)算。
java代碼如下：
CPUUsage.java
- package com;
- import java.io.BufferedReader;
- import java.io.File;
- import java.io.FileReader;
- import java.io.IOException;
- public class CPUUsage
- {
- private static final String procPath = File.separator + "proc" + File.separator + "stat";
- public static void main(String[] args)
- {
- CPUTime startTime = new CPUTime();
- CPUTime endTime = new CPUTime();
- getcpuTime(startTime);
- try
- {
- Thread.sleep(1000);
- }
- catch (InterruptedException e)
- {
- e.printStackTrace();
- }
- getcpuTime(endTime);
- double cpuUsage = 0;
- long totalTime = endTime.getTotalTime() - startTime.getTotalTime();
- if (totalTime == 0)
- {
- cpuUsage = 0;
- }
- else
- {
- cpuUsage = 1 - (((double) (endTime.getIdleTime() - startTime.getIdleTime())) / totalTime);
- }
- System.out.println("the cpu usage is: " + cpuUsage * 100 + "%");
- }
- private static void getcpuTime(CPUTime t)
- {
- BufferedReader fr = null;
- try
- {
- fr = new BufferedReader(new FileReader(new File(procPath)));
- String oneLine = null;
- while ((oneLine = fr.readLine()) != null)
- {
- if (oneLine.startsWith("cpu "))
- {
- String[] vals = oneLine.substring(4).split(" ");
- if (vals.length != 10)
- {
- System.err.println("read an error line string!");
- }
- else
- {
- t.setTotalTime(Long.parseLong(vals[1]) + Long.parseLong(vals[2]) + Long.parseLong(vals[3])
- + Long.parseLong(vals[4]) + Long.parseLong(vals[5]) + Long.parseLong(vals[6])
- + Long.parseLong(vals[7]) + Long.parseLong(vals[8]) + Long.parseLong(vals[9]));
- t.setIdleTime(Long.parseLong(vals[4]));
- break;
- }
- }
- }
- }
- catch (NumberFormatException e)
- {
- e.printStackTrace();
- }
- catch (IOException e)
- {
- e.printStackTrace();
- }
- finally
- {
- if (fr != null)
- {
- try
- {
- fr.close();
- }
- catch (IOException e)
- {
- e.printStackTrace();
- }
- }
- }
- }
- }
CPUTime.java
- package com;
- public class CPUTime
- {
- private long totalTime;
- private long idleTime;
- public CPUTime()
- {
- totalTime = 0;
- idleTime = 0;
- }
- public long getTotalTime()
- {
- return totalTime;
- }
- public void setTotalTime(long totalTime)
- {
- this.totalTime = totalTime;
- }
- public long getIdleTime()
- {
- return idleTime;
- }
- public void setIdleTime(long idleTime)
- {
- this.idleTime = idleTime;
- }
- }
文章名稱：通過(guò)/proc/stat文件信息，java實(shí)現(xiàn)計(jì)算cpu使用率
URL地址：http://www.5511xx.com/article/coepiih.html
