# . 查看主进程占用cpu高

top

#     java

# . 按照线程占用cpu由高到低进行排查：

ps -mp  -o THREAD,tid,time | sort -rn |head -

# USER     %CPU PRI SCNT WCHAN  USER SYSTEM   TID     TIME

# root      1.6   -    - -         -      -     - ::

# root      0.1      - futex_    -      -   ::

# root      0.1      - futex_    -      -   ::

# root      0.1      - futex_    -      -   ::

# root      0.0      - skb_re    -      -   ::

# . 将线程号转化为16进制：

printf "%x\n"

6e7

# . 通过主进程搜索所有的线程执行的内容

#    注意点:

#        项目运行的用户

#        使用的jdk版本下的jstack去查看

flag="0x"

sudo -u root /opt/jdk1..0_191/bin/jstack  |grep ${flag}6e7 -A 

### 将整个流程写成脚本，查找tomcat占用CPU高的线程日志

pid=$(ps -ef|grep tomcat|grep -v grep|awk '{print $2}'|head -)

flag="0x"

jstack="/opt/jdk1.8.0_191/bin/jstack"

for tpid in `ps -mp ${pid} -o THREAD,tid,time | sort -rn |head -|awk '$8 ~ /[0-9]+/ {print $8}'`

do

    tpid_16hex=$(printf "%x\n" ${tpid})

    echo "------------------------------------- tpid:[ ${tpid} ] -----------------------------------------------------"

    sudo -u root ${jstack} ${pid} |grep ${flag}${tpid_16hex} -A

done