RSLogix 5000 Periodic Task Time

Hello everyone,
I am new to PLCs, what will happen if I set the Period of a Periodic task lesser than its execution Time for ControlLogix Controller. For example, I set the Period of periodic task as 10ms, however, it took 15ms to execute.
As per my understanding, if I have only one continuous task and this particular periodic, then nothing will happen unless my watchdog is lesser than the execution time, if so a Major fault will occur. Please validate if I am correct in my understanding?

In your example, every 10ms the periodic task would interrupt itself. Each time it would restart at the beginning of the task and it would be interrupted before it could complete the task. This will cause a watchdog fault in either the continuous task or in the periodic task.

Each task has its own watchdog timer. The watchdog timer starts timing when the task begins and then it resets when that task completes. If that task is unable to complete, then the timer will continue running until it expires and cause a major fault. The watchdog fault could occur in the continuous task or in the periodic task. Extending the watchdog time won't help since the controller is caught in a loop from which it cannot escape. Extending the watchdog time is unsafe as it allows the compromised system to keep running for a longer time before faulting.

OG