SCHED_RR
also: Round-Robin, SCHED_RR scheduling
A Linux CPU scheduling policy that allocates CPU time to processes in round-robin fashion with a fixed time quantum. Each process of the same priority gets an equal slice of CPU time before yielding to the next process.
SCHED_RR (Round-Robin) is a real-time scheduling class in Linux that ensures fair CPU distribution among processes of identical priority. When a process's time quantum (typically 100ms) expires, the scheduler moves it to the back of the queue and selects the next process at that priority level.
This differs from SCHED_FIFO (First-In-First-Out), where a process runs until it voluntarily yields or a higher-priority process arrives. SCHED_RR is useful for interactive real-time applications that need responsive behavior without starvation.
Example: Three real-time processes at priority 10 using SCHED_RR will each get roughly equal CPU time: Process A runs 100ms, then Process B runs 100ms, then Process C runs 100ms, repeating in rotation.