IFSM 310 Hardware and Software Infrastructure Concepts

For problems 1 and 2, a computer has the following four processes that have arrived in the ready queue in the sequence shown below. NOTES: (1) Time slicing is not used, therefore, there are no mandatory time outs. (2) I/O operations only occur one time during the process execution.

• Process 1 has a run time of 30 seconds, a priority of 2, and it will require 15 seconds of I/O after an initial 10 seconds of execution.
• Process 2 has a run time of 20 seconds, a priority of 1, and it will require 10 seconds of I/O after an initial 5 seconds of execution.
• Process 3 has a run time of 15 seconds and a priority of 2.
• Process 4 has a run time of 25 seconds and a priority of 1, and it will require 15 seconds of I/O after an initial 10 seconds of execution

(HINT for problems 1 and 2: Review Module 6 section 2.1.2 for the definitions of these scheduling algorithms and Self-Assessment problems 1-4.)

1. (2.5 points) If the Round Robin Scheduling algorithm is used, which process completes first? Why? At what time does it complete?

2. (2.5 points) If the Round Robin with Priority Queues Scheduling algorithm is used, which process completes second? Why? At what time does it complete?

3. (2 points) The manual for a popular operating system points out that the number of concurrent users on the system can be increased if the users are sharing programs, such as editors, mail readers, or compilers. What characteristics of virtual storage make this possible?

4. (3 points) Using a variable-partitioned multiprogramming memory, which of the four holes shown below will be used to satisfy a 45 KB program requirement under the conditions of:

___ First-fit
___ Best-fit
___ Worst-fit

(HINT: See Module 6 section 2.2.3 and Self Assessment problem 6.)