The xlock process is frozen

The xlock process is frozen

[MDAS terminals(sbt* & alt*)]

The xlock process sometimes freezes on the terminal.
If you encounter this problem, please try the following steps.

[How to kill the frozen xlock process]
1. Enter the "Ctrl + Alt + F2" key to switch the virtual console.
2. Input your account name and your password into the displayed terminal.
3. Execute "ps -aux | grep xlock" and check the PID of the xlock.
4. Execute "kill -9 PID_of_xlock".
5. Execute "exit" to logout from this terminal.
6. Enter the "Ctrl + Alt + F1" key to switch the virtual console. The xlock process should be killed.