Define Multi-level Queue Scheduling and How to Increase CPU Time

Define Multi-level Queue Scheduling and How to Increase CPU Time

Thank you for your question, to answer you, I will first start by explaining what Scheduling is which is a method by which threads and processes are given access to the system resources. The need for scheduling algorithm arises from the requirement for multitasking and multiplexing.

There are the following scheduling Algorithms;

·         First in First Out (FIFO)

·         Shortest Remaining Time- Shortest job first

·         Fixed priority Preemptive scheduling

·         Round Robin(RR)

·         Multi-level Queue

A multilevel queue system is designed to give preference to short jobs; Give preference to I/O bound processes and separate processes into categories based on their need for the processor. This is what basically happens;

Ø  A process is given just one chance to complete at a given queue level, by partitioning the ready queue into several separate queues

Ø   Processes are permanently assigned to one queue, based on properties of the process such as memory size, process priority, or process type.

Ø  Each queue has absolute priority over lower-priority queues and also each queue has its own scheduling algorithm. The foreground queue might be scheduled by an RR algorithm, while the background queue is scheduled by an FCFS algorithm.

Ø  Moreover, there must be scheduling among the queues, which is commonly implemented as fixed-priority pre-emptive scheduling. For instance, the foreground queue may have absolute priority over the background queue

Having elaborated this, the scheduler’s main concern is Throughput, Latency and Waiting Time hence to know which is the best algorithm to increase the CPU time allocated for a particular process; I have put this together for you.

I hope the Multi level queue scheduling is now clear. Thanks.