• A multilevel queue scheduling algorithm divides the ready queue in several separate queues, for example
• In a multilevel queue scheduling processes are lastingly assigned to one queue.
• The processes are permanently allotted to one another, based on some property of the process, for example
• Process type
• Memory size
• Process priority
• Algorithm choose the process from the engaged queue that has the highest priority, and run that process either
• Preemptive or Non-preemptively
• Every queue has its own scheduling algorithm or policy.
• Possibility 1
If every queue has absolute priority over lower-priority queues then no one process in the queue could run unless the queue for the highest-priority processes was all blank.
• As, in the above figure no process in the lot queue could run unless the queues for system processes, interrelting processes, and interactive editing processes will all blank.
• Possibility 2
If there is a time slice between the queues then each and every queue gets a convinced amount of CPU times, which it can then schedule between the processes in its queue. For instance;
• 80% of the CPU time to forefront queues using RR.
• 20% of the CPU time to backdrop queues using FCFS.
• Seeing as processes do not move between queues so, this plan has the advantage of low scheduling overhead, but it is inflexible.