Java-性能调优实战(jps、jstack)

找最耗CPU的线程

1. 找出java进程

[ ~]# jps
9939 Resin
9874 WatchdogManager
9926 Jps

2. 找java进程下所有的线程　　

[ ~]# top -Hp 9939 -n 1
top - 17:45:17 up 40 days,  7:11,  2 users,  load average: 0.00, 0.00, 0.00
Tasks: 405 total,   0 running, 405 sleeping,   0 stopped,   0 zombie
Cpu(s):  0.3%us,  0.3%sy,  0.0%ni, 99.3%id,  0.0%wa,  0.0%hi,  0.0%si,  0.0%st
Mem:  16331812k total,  4357204k used, 11974608k free,   287632k buffers
Swap:  6291452k total,        0k used,  6291452k free,  2663424k cached

  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND                                                                                            
 1399 root      20   0 5418m 822m  23m S  2.0  5.2   0:00.50 java                                                                                                
 9939 root      20   0 5418m 822m  23m S  0.0  5.2   0:00.00 java                                                                                                
 9941 root      20   0 5418m 822m  23m S  0.0  5.2   0:35.07 java                                                                                                
 9942 root      20   0 5418m 822m  23m S  0.0  5.2   1:34.61 java                                                                                                
 9943 root      20   0 5418m 822m  23m S  0.0  5.2   1:34.17 java                                                                                                
 9944 root      20   0 5418m 822m  23m S  0.0  5.2   1:34.37 java         

3. nid 1399 的16进制

[ ~]# printf '%x
' 1399
577

4. 找java线程　　

[ ~]# jstack 9939 | grep 577
"resin-port-127.0.0.1:35080-launcher" daemon prio=10 tid=0x00007fa6b805d000 nid=0x577 waiting on condition [0x00007fa5ddd98000]

5. 找代码