Chapter 1 Questions

1.12 In a multiprogramming and time-sharing environment, several users share the system simultaneously. This situation can result in various security problems.

a. What are two such problems?
b. Can we ensure the same degree of security in a time-shared machine as in a dedicated machine? Explain your answer

1.14 Under what circumstances would a user be better off using a timesharing system rather than a PC or a single-user workstation?

1.15 Describe the differences between symmetric and asymmetric multiprocessing. What are three advantages and one disadvantage of multiprocessor

1.20 Direct memory access is used for high-speed I/O devices in order to avoid increasing the CPU’s execution load.

a. How does the CPU interface with the device to coordinate the transfer?
b. How does the CPU know when the memory operations are complete?
c. The CPU is allowed to execute other programs while the DMA controller is transferring data. Does this process interfere with the execution of the user programs? If so, describe what forms of interference are caused.

1.24 Discuss, with examples, how the problem of maintaining coherence of cached data manifests itself in the following processing environments:

a. Single-processor systems
b. Multiprocessor systems
c. Distributed systems

1.25 Describe a mechanism for enforcing memory protection in order to prevent a program from modifying the memory associated with other

1.27 Describe some of the challenges of designing operating systems for mobile devices compared with designing operating systems for traditional

1.29 Describe some distributed applications that would be appropriate for a peer-to-peer system.