Process Schedule Log for Steven Robbins generated Mon Mar 01 20:16:42 CST 1999

Process Scheduling Simulator Beta 0.994L058 by S. Robbins supported by NSF grants DUE-9750953 and DUE-9752165.
See /nsf for simulator information.
Java version 1.1.6 OS Solaris version 2.x 16601386822


Group Information for 2 Groups
Name Commentary Duration CPU Burst I/O Burst Priority
part1_group_1 Group 1 from run part1 uniform 1000.00 2000.00 exponential 100.00 constant 1000.00 1.00
part1_group_2 Group 2 from run part1 uniform 200.00 400.00 exponential 20.00 constant 100.00 1.00


Creator Information for 1 Creator
Name Commentary Seed Group Processes First Arrival Interarrival
part1_creator Creator from run part1 123456 part1_group_1 10 0.0 constant 0.00
part1_group_2 10 0.0 constant 0.00


Experimental Run Information for 1 Run
Name Commentary Creator Algorithm Key
part1 Two types of processes part1_creator RR200.0
Experimental Runs For 1 Experiment
Experiment Commentary Run Modifications
part1 Two runs with different quantums part1_1 key Round Robin: Quantum = 200
part1_2 algorithm RR 20
key Round Robin: Quantum = 20

Starting experiment of 2 runs from part1


Mon Mar 01 20:16:43 CST 1999

Starting run from part1_1

Experimental Run Information
Name Commentary Creator Algorithm Key
part1_1 Two types of processes part1_creator RR200.0
Starting to run events using RR 200.00
990 events done in 467 milliseconds

Mon Mar 01 20:16:44 CST 1999

Starting run from part1_2

Experimental Run Information
Name Commentary Creator Algorithm Key
part1_2 Two types of processes part1_creator RR 20
Starting to run events using RR 20.00
2604 events done in 1320 milliseconds



Mon Mar 01 20:16:48 CST 1999

Description Algorithm Time Processes Finished CPU Utilization Throughput Turnaround Time Waiting Time
part1_1 RR 200.00 27837.96 20 20 .69589 .000718 14635.04 4811.43
part1_2 RR 20.00 28427.89 20 20 .68145 .000704 14389.78 4566.18


Turnaround Time Waiting Time
Description Algorithm Average Minimum Maximum SD Average Minimum Maximum SD
part1_1 RR 200.00 14635.04 5783.28 27837.96 8088.04 4811.43 2764.39 6842.14 62.15
part1_2 RR 20.00 14389.78 3906.61 28427.89 9362.31 4566.18 2974.55 6739.06 44.61


Mon Mar 01 20:16:51 CST 1999

Waiting Time

Bins: 10 Min: 0.00 Max: 7000.00
Mon Mar 01 20:17:03 CST 1999

Gantt Chart for Round Robin: Quantum = 200
Mon Mar 01 20:17:17 CST 1999

Gantt Chart for Round Robin: Quantum = 20

Process Schedule Log for Steven Robbins completed Mon Mar 01 20:17:25 CST 1999


This experiment consists of two runs with the same set of processes using Round Robin with two different quantums.

A set of 10 long (CPU burst) jobs enters the ready queue first, followed by a set of shorter jobs. When the quantum is large, the first set of processes execute for a long time making the shorter processes wait. When the quantum is shorter, comparable to the burst time of the shorter processes, these short processes wait less time and leave the system sooner, reducing the average waiting time by a small amount.

This is most readily seem by comparing the Gantt charts fo the two runs. The second Gantt chart shows that the last 10 processes spend less time in the ready queue (the green part of the chart).