CS3530 Operating Systems
Assignment No. 1 (Due Tuesday, August 25) 


Study of Performance Metrics for a Simple Batch System.


Observation of general behavior of a simple batch system. Computation of some relevant performance metrics.  

The model of the batch system is implemented in C++ (batch.cpp) using Psim3 package. 

Copy the "batch.cpp" source file from the system directory /home/jgarrido/psim3 on CS3, then compile, and link. 

The Psim3 script Uses the Unix GNU C++ compiler on the CS3 machine with Linux. 
Run the program at least three times. 

Write a report describing the characteristics of the operating system modeled. Use the usual guidelines for structuring the 
report. Include at the end of the report your answers to the following questions. 
* What aspect of an operating system is the model representing? 
* What performance measures does the model compute? 
* What is noticeable in the dynamic behavior of the system? 

After changing some of the parameters in the model (the workload) and recompiling. 
* What changes in the results do you notice? 
* What other performance measures can this model compute? 

Increasing the amount of memory twofold of the operating system modeled has an effect in its performance. Implement these 
changes in the model and analyze the results. If the model needs to change the representation of a CPU twice as fast as the 
previous one, how can you implement this modification? 


The following are some of the relevant variables (input parameters) that affect performance (see source code):

  
  mean_int_arr
  mean_ser
  mem_l
  mem_up

The first two variables correspond to system parameters, the other four, workload parameters.