网站全栰培训,被网络运营公司骗了去哪里投诉,重庆网站备案必须到核验点,山东济南seo优化1、top后按c查看最耗cpu的进程#xff0c;得到pid 2、top -Hp pid 查看该进程里的线程资源使用情况#xff0c;找到最耗资源的线程的pid 3、jstack pid来查看进程的各个线程栈#xff0c;注意这里的pid是第一步中进程的pid#xff0c;不是第二步得到的线程id 4、将第二步得…1、top后按c查看最耗cpu的进程得到pid 2、top -Hp pid 查看该进程里的线程资源使用情况找到最耗资源的线程的pid 3、jstack pid来查看进程的各个线程栈注意这里的pid是第一步中进程的pid不是第二步得到的线程id 4、将第二步得到的pid转成16进制之后在线程栈信息里查找nid等于pid16进制的就找到最耗资源的线程的栈信息 话不多说了先来看代码吧 public class Test{public static void main(String args[]){for(int i0;i10;i){new Thread(){public void run(){try{Thread.sleep(100000);}catch(Exception e){}}}.start();}Thread tnew Thread(){public void run(){int i0;while(true){i(i)/100;}}};t.setName(Busiest Thread);t.start();}
} 这个例子里新创建了11个线程其中10个线程没干什么事主要是sleep另外有一个线程在循环里一直跑着可以想象这个线程是这个进程里最耗cpu的线程了那怎么把这个线程给抓出来呢 首先我们可以通过top -Hp pid来看这个进程里所有线程的cpu消耗情况得到类似下面的数据 $ top -Hp 18207
top - 19:11:43 up 573 days, 2:43, 2 users, load average: 3.03, 3.03, 3.02
Tasks: 44 total, 1 running, 43 sleeping, 0 stopped, 0 zombie
Cpu(s): 18.8%us, 0.0%sy, 0.0%ni, 81.1%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Mem: 99191752k total, 98683576k used, 508176k free, 128248k buffers
Swap: 1999864k total, 191064k used, 1808800k free, 17413760k cachedPID USER PR NI VIRT RES SHR S %CPU %MEM TIME COMMAND
18250 admin 20 0 26.1g 28m 10m R 99.9 0.0 0:19.50 java Test
18207 admin 20 0 26.1g 28m 10m S 0.0 0.0 0:00.00 java Test
18208 admin 20 0 26.1g 28m 10m S 0.0 0.0 0:00.09 java Test
18209 admin 20 0 26.1g 28m 10m S 0.0 0.0 0:00.00 java Test
18210 admin 20 0 26.1g 28m 10m S 0.0 0.0 0:00.00 java Test
18211 admin 20 0 26.1g 28m 10m S 0.0 0.0 0:00.00 java Test
18212 admin 20 0 26.1g 28m 10m S 0.0 0.0 0:00.00 java Test
18213 admin 20 0 26.1g 28m 10m S 0.0 0.0 0:00.00 java Test
18214 admin 20 0 26.1g 28m 10m S 0.0 0.0 0:00.00 java Test
18215 admin 20 0 26.1g 28m 10m S 0.0 0.0 0:00.00 java Test
18216 admin 20 0 26.1g 28m 10m S 0.0 0.0 0:00.00 java Test
18217 admin 20 0 26.1g 28m 10m S 0.0 0.0 0:00.00 java Test
18218 admin 20 0 26.1g 28m 10m S 0.0 0.0 0:00.00 java Test
18219 admin 20 0 26.1g 28m 10m S 0.0 0.0 0:00.00 java Test
18220 admin 20 0 26.1g 28m 10m S 0.0 0.0 0:00.00 java Test
18221 admin 20 0 26.1g 28m 10m S 0.0 0.0 0:00.00 java Test
18222 admin 20 0 26.1g 28m 10m S 0.0 0.0 0:00.00 java Test
18223 admin 20 0 26.1g 28m 10m S 0.0 0.0 0:00.00 java Test
18224 admin 20 0 26.1g 28m 10m S 0.0 0.0 0:00.00 java Test
18225 admin 20 0 26.1g 28m 10m S 0.0 0.0 0:00.00 java Test
18226 admin 20 0 26.1g 28m 10m S 0.0 0.0 0:00.00 java Test
18227 admin 20 0 26.1g 28m 10m S 0.0 0.0 0:00.00 java Test 拿到这个结果之后我们可以看到cpu最高的线程是pid为18250的线程占了99.8% PID USER PR NI VIRT RES SHR S %CPU %MEM TIME COMMAND
18250 admin 20 0 26.1g 28m 10m R 99.9 0.0 0:19.50 java Test 接着我们可以通过jstack pid的输出来看各个线程栈: $ jstack 18207
2016-03-30 19:12:23
Full thread dump OpenJDK 64-Bit Server VM (25.66-b60 mixed mode):Attach Listener #30 daemon prio9 os_prio0 tid0x00007fb90be13000 nid0x47d7 waiting on condition [0x0000000000000000]java.lang.Thread.State: RUNNABLEDestroyJavaVM #29 prio5 os_prio0 tid0x00007fb96245b800 nid0x4720 waiting on condition [0x0000000000000000]java.lang.Thread.State: RUNNABLEBusiest Thread #28 prio5 os_prio0 tid0x00007fb91498d000 nid0x474a runnable [0x00007fb9065fe000]java.lang.Thread.State: RUNNABLEat Test$2.run(Test.java:18)Thread-9 #27 prio5 os_prio0 tid0x00007fb91498c800 nid0x4749 waiting on condition [0x00007fb906bfe000]java.lang.Thread.State: TIMED_WAITING (sleeping)at java.lang.Thread.sleep(Native Method)at Test$1.run(Test.java:9)Thread-8 #26 prio5 os_prio0 tid0x00007fb91498b800 nid0x4748 waiting on condition [0x00007fb906ffe000]java.lang.Thread.State: TIMED_WAITING (sleeping)at java.lang.Thread.sleep(Native Method)at Test$1.run(Test.java:9)Thread-7 #25 prio5 os_prio0 tid0x00007fb91498b000 nid0x4747 waiting on condition [0x00007fb9073fe000]java.lang.Thread.State: TIMED_WAITING (sleeping)at java.lang.Thread.sleep(Native Method)at Test$1.run(Test.java:9)Thread-6 #24 prio5 os_prio0 tid0x00007fb91498a000 nid0x4746 waiting on condition [0x00007fb9077fe000]java.lang.Thread.State: TIMED_WAITING (sleeping)at java.lang.Thread.sleep(Native Method)at Test$1.run(Test.java:9)
... 上面的线程栈我们注意到nid的值其实就是线程ID它是十六进制的我们将消耗cpu最高的线程18250转成十六进制0X47A然后从上面的线程栈里找到nid0X47A的线程其栈为 Busiest Thread #28 prio5 os_prio0 tid0x00007fb91498d000 nid0x474a runnable [0x00007fb9065fe000]java.lang.Thread.State: RUNNABLEat Test$2.run(Test.java:18) 即将最耗cpu的线程找出来了是Businest Thread转载于:https://www.cnblogs.com/yifanSJ/p/9764965.html
