In a data processing system having a processor and a memory protection unit (MPU), a method includes scheduling, in the processor, a new process to be executed; writing a process identifier (PID) corresponding to the new process into storage circuitry of the MPU; in response to updating the storage circuitry with the PID, configuring the MPU with region descriptors corresponding to the new process; configuring, by an operating system of the processor, the processor to execute the new process in parallel with the configuring the MPU with the region descriptors; and when the configuring the MPU is complete, giving control to the new process to execute on the processor.