...
For the emulator, the message means that the timer thread runs with normal priority, not real-time. It should be considered as a warning message and does not impact the execution of the emulator.
Please have a look at this article Processes requiring Real-Time Scheduling fail with "sched_setscheduler: Operation not permitted" error or similar on Red Hat customer portal.
To avoid this message during startup, one solution is to upgrade Linux to at least version 8.7 (this error message is not more displayed).
...