FreeRTOS FAQ – Scheduling
This is a subsection of the full FAQ
How are tasks of equal priority scheduled?
Round robin – Ready state tasks that share a priority “take turns” to run.
How are tasks that share the idle priority scheduled?
As per tasks that share any other priority. However, the configIDLE_SHOULD_YIELD configuration constant can be used to force the idle task to yield after a single iteration of its loop if other idle priority application tasks are able to run.