Differences between multilevel queue and multi level feedback queue in operating system

 

Here is a comparison between the Multilevel Queue (MLQ) and Multi-level Feedback Queue (MLFQ) scheduling algorithms in operating systems :

Feature	Multilevel Queue (MLQ)	Multi-level Feedback Queue (MLFQ)
Purpose	Separates processes into different priority levels	Dynamically adjusts process priority levels based on their behavior
Priority levels	Fixed priority levels	Adjustable priority levels
Task placement	Tasks placed in specific priority levels	Tasks move between priority levels based on behavior
Performance	Depends on the number of priority levels	Higher performance compared to MLQ
Latency	High latency for low-priority tasks	Lower latency compared to MLQ
Task prioritization	Prioritizes tasks based on their assigned priority level	Prioritizes tasks based on their behavior and recent CPU usage
Context switching	Lower rate of context switching	Higher rate of context switching
CPU utilization	Depends on the priority levels assigned	Higher CPU utilization compared to MLQ
Responsiveness	Faster response time for high-priority tasks	Faster response time for all tasks compared to MLQ
Memory requirements	Low memory requirements	Moderate memory requirements
Preemptive or Non-Preemptive	Typically preemptive	Preemptive
Interrupt handling	Handles interrupts	Handles interrupts
Task scheduling	Schedules individual tasks	Schedules individual tasks
Fairness	Fair to tasks in each priority level	Fair to all tasks
Aging	May implement aging to prevent low-priority tasks from starvation	Implements aging to prevent low-priority tasks from starvation
Feedback mechanism	None	Implements feedback mechanism to adjust priority levels

Note that the exact behavior and performance of the MLQ and MLFQ algorithms can vary based on the specific implementation and the workload being scheduled. MLFQ is a more advanced and sophisticated version of MLQ and provides improved performance and responsiveness compared to MLQ.