排查一次CPU100%的情况

1:查找cpu 使用情况   top -c

2:查看具体进程的 线程使用cpu情况  top -Hp 18884

3：watch pstack 18890   或者  pstack 18890 > a.txt

由于ubuntu 中的pstack 命令有问题 网上找了代码 另存为 mypstack 

  1 #!/bin/sh
  2 
  3 if test $# -ne 1; then
  4     echo "Usage: `basename $0 .sh` <process-id>" 1>&2
  5     exit 1
  6 fi
  7 
  8 if test ! -r /proc/$1; then
  9     echo "Process $1 not found." 1>&2
 10     exit 1
 11 fi
 12 
 13 # GDB doesn't allow "thread apply all bt" when the process isn't
 14 # threaded; need to peek at the process to determine if that or the
 15 # simpler "bt" should be used.
 16 
 17 backtrace="bt"
 18 if test -d /proc/$1/task ; then
 19     # Newer kernel; has a task/ directory.
 20     if test `/bin/ls /proc/$1/task | /usr/bin/wc -l` -gt 1 2>/dev/null ; then
 21         backtrace="thread apply all bt"
 22     fi
 23 elif test -f /proc/$1/maps ; then
 24     # Older kernel; go by it loading libpthread.
 25     if /bin/grep -e libpthread /proc/$1/maps > /dev/null 2>&1 ; then
 26         backtrace="thread apply all bt"
 27     fi
 28 fi
 29 
 30 GDB=${GDB:-/usr/bin/gdb}
 31 
 32 if $GDB -nx --quiet --batch --readnever > /dev/null 2>&1; then
 33     readnever=--readnever
 34 else
 35     readnever=
 36 fi
 37 
 38 # Run GDB, strip out unwanted noise.
 39 $GDB --quiet $readnever -nx /proc/$1/exe $1 <<EOF 2>&1 | 
 40 set width 0
 41 set height 0
 42 set pagination no
 43 $backtrace
 44 EOF
 45 /bin/sed -n \
 46     -e 's/^\((gdb) \)*//' \
 47     -e '/^#/p' \
 48     -e '/^Thread/p'
 49 #end