CPU Scheduling Algorithms Overview

4 Questions

Match the following CPU scheduling algorithms with their primary characteristics:

First Come First Served (FCFS) = Tasks are scheduled based on arrival time Round Robin (RR) = All tasks receive equal CPU time Shortest Job Next (SJN) = Jobs are scheduled based on processing times

Connect the CPU scheduling algorithm with the potential issue it may face:

First Come First Served (FCFS) = Risk of starvation for long-waiting tasks Round Robin (RR) = May not prioritize short processes over long ones Shortest Job Next (SJN) = Assumption that smaller jobs complete faster

Match the CPU scheduling algorithm with its impact on CPU cycle utilization:

First Come First Served (FCFS) = Doesn't take into account process length Round Robin (RR) = Better utilization by allowing other jobs to run Shortest Job Next (SJN) = Minimizes idle time by running shorter jobs first

Link the CPU scheduling algorithm with its focus on fairness and efficiency:

First Come First Served (FCFS) = Fair distribution of resources Round Robin (RR) = Balancing efficiency and fairness tradeoffs Shortest Job Next (SJN) = Higher throughput by running shorter jobs first

Study Notes

CPU Scheduling Algorithms play an integral role in managing resource allocation in computing systems. They determine which processes get access to the Central Processing Unit (CPU) when multiple tasks request it simultaneously. These algorithms help ensure a fair distribution of resources while maximizing system performance. Some common algorithms used today include:

First Come First Served (FCFS)

One of the most straightforward methods is First Come First Served where tasks are scheduled based on their arrival time in the queue. This method can lead to starvation if a task has been waiting longer than others. It also doesn't take into account the length of each process.

Round Robin (RR)

In Round Robin scheduling, all tasks receive equal amounts of CPU time. If one job hogs the CPU for too long without making any progress, other jobs will have more opportunities to run leading to better utilization of available CPU cycles. However, this algorithm does not necessarily prioritize short processes over large ones.

Shortest Job Next (SJN)

The Shortest Job Next (SJN) method schedules jobs according to their processing times, with the assumption that smaller jobs complete faster and free up the CPU sooner. This approach usually leads to higher throughput because it minimizes idle time by running shorter jobs before larger ones.

These three approaches represent different tradeoffs between efficiency and fairness. For example, FCFS may result in high throughput since the longest job gets its turn next; however, it might lead to unfair conditions where some jobs wait much longer than others. On the other hand, RR provides good balance among jobs and ensures they all have enough CPU time — but requires extra overhead for context switching. Finally, SJN aims for maximum CPU utilization while ensuring that small jobs won't make bigger ones wait unnecessarily.

Choosing the right strategy depends heavily on specific needs within your system design. In many cases, efficacy comes from combining these techniques within complex hybrid strategies tailored specifically towards addressing your unique requirements.