CS 3530 OPERATING SYSTEMS - Fall 2009

ASSIGNMENT NO. 3  BASIC SCHEDULING POLICIES (Due Tuesday Sept 15)


Study the behavior of a batch OS scheduling with FCFS, SJF and RR using the following simulation models:
	batmfcfs.cpp   (Batch OS with FCFS scheduling) 
      batmsjf.cpp   (Batch OS with SJF (SPN) scheduling) 
      rrsched.cpp   (RR scheduling Time-sharing ) 

Copy these files from the "/home/jgarrido/psim3" system directory on the CS3 server. 

When running these models, the first two generate an output file with a ".dat" extension.

Note: these models have five classes of processes although the FCFS and RR scheduling are mainly scheduling policies for single-class systems; all processes are treated alike.

In the last part of your report include your answers to the following questions.

1. What are the main differences with the previous models?
2. What would observable in the model with RR scheduling for a single-class system?
3. Change the pameters of the FCFS model so that there are no jobs rejected. What are your conclusions. Increase the system memory and repeat.
4. Identify the performance measures that conflict with each other. Give your reasons for this. Which ones are more important?
5. Change the time slice of the RR model. What are your conclusions after reading the trace and preformance measures.
6. Analyse the simulation run of the RR model. RR does not have the best performance, Why?. What advantages does RR have compared to the other scheduling policies?