DEPARTMENT OF INFORMATION AND TECHNOLOGY
SUBJECT CODE: CS8493 SUBJECT NAME: OPERATING SYSTEMS
SEM: IV REGULATION: 2017
1. Difference Between Multiprocessor and Multicore Organization:
Aspect Multiprocessor Multicore
Single CPU with multiple cores on the
Definition Uses multiple physical CPUs in a system.
same chip.
Processors communicate via shared memory or Cores communicate directly on the
Communication
interconnect. same chip.
2. Define cache memory
Cache Memory Definition:
Cache memory is a small, high-speed storage located close to the CPU, used to temporarily store
frequently accessed data and instructions, reducing the time needed to access data from the main
memory.
3. Define deadlock detection
Deadlock Detection Definition:
Deadlock detection is the process of identifying a state in which a set of processes is blocked,
waiting for resources held by each other in a cyclic dependency, preventing further progress.
Detection algorithms are used to resolve the deadlock.
4. What is mutex lock?
Mutex Lock Definition:
A mutex (mutual exclusion) lock is a synchronization mechanism used in multithreading to protect shared
resources. It allows only one thread to access the resource at a time, preventing race conditions by
ensuring mutual exclusion.
5. Define swapping in storage management
Swapping in Storage Management:
Swapping is a memory management technique where processes are temporarily moved between
the main memory and secondary storage (disk) to optimize memory usage and ensure execution
of multiple processes.
6. What is segmentation ?
Segmentation Definition:
Segmentation is a memory management technique that divides a program into logical units or
segments, such as code, data, and stack. Each segment is independently addressable, allowing for
more efficient memory utilization and protection.
7. list the I/O systems
Types of I/O Systems:
Programmed I/O: CPU directly controls I/O operations.
Interrupt-Driven I/O: CPU is alerted by interrupts when I/O is ready.
Direct Memory Access (DMA): Data is transferred between memory and I/O devices without
continuous CPU involvement.
8. State the allocation methods.
Allocation Methods:
1. Contiguous Allocation: Files are stored in consecutive memory blocks.
2. Linked Allocation: Files are stored in non-contiguous blocks linked together.
3. Indexed Allocation: An index block holds pointers to the file's data blocks.
9. What is the input-output management?
Input-Output Management:
Input-output management is the process of coordinating and controlling the communication
between the CPU and peripheral devices, ensuring efficient data transfer, device allocation, and
handling interrupts for seamless operation.
10. compare the ios and android
Comparison of iOS and Android:
Platform: iOS is exclusive to Apple devices, while Android is open-source and used by various
manufacturers.
Customization: Android offers extensive customization, whereas iOS focuses on simplicity and
uniformity.
PART-B
11. a.i) Explain various structure of operating system give the answers in 6 marks and split the marks
accordingly
Various Structures of Operating Systems (6 Marks)
Monolithic Structure (2 Marks)
Layered Structure (1.5 Marks)
Microkernel Structure (1.5 Marks)
Client-Server Structure (1 Mark)
ii) Explain the purpose & importance of system calls in detail with example
Purpose & Importance of System Calls (7 Marks)
Introduction to System Calls (2 Marks)
Purpose of System Calls (2 Marks)
Importance of System Calls (2 Marks)
Example of System Calls (1 Mark)
11.b) i) State the basic function of OS and DMA
Basic Functions of OS and DMA (5 Marks)
1. Basic Functions of an Operating System (3 Marks)
Process Management (1 Mark):
Memory Management (1 Mark):
File System Management (1 Mark):
Basic Function of Direct Memory Access (DMA) (2 Marks)
Efficient Data Transfer (1 Mark):
Reduced CPU Load (1 Mark):
ii) explain the advantages and disadvantages of using the same system call interface for manipulating
both files and devices
Advantages and Disadvantages of Using the Same System Call Interface for Manipulating Both
Files and Devices (8 Marks)
Advantages (4 Marks)
1. Simplicity and Uniformity (1 Mark)
Consistency in Application Programming (1 Mark)
Easier System Maintenance (1 Mark)
Flexibility in Resource Management (1 Mark)
Disadvantages (4 Marks)
1. Performance Overhead (1 Mark).
2. Lack of Fine-grained Control (1 Mark).
3. Potential for Increased Complexity (1 Mark)
Security Risks (1 Mark).
12 a) Discuss how the following pairs of scheduling criteria conflict in certain settings. i) CPU utilization
and response time. iii) I/O device utilization and CPU utilization. ii) Average turn around time and
maximum waiting time (13)
CPU Utilization vs. Response Time: (4 Marks)
CPU utilization: 1 Mark
Response time: 1 Mark
Conflict between them: 2 Marks
I/O Device Utilization vs. CPU Utilization: (4 Marks)
I/O utilization: 1 Mark
CPU utilization: 1 Mark
Conflict between them: 2 Marks
Average Turnaround Time vs. Maximum Waiting Time: (5 Marks)
Turnaround time: 1 Mark
Waiting time: 1 Mark
Conflict between them: 3 Marks
12 b) Describe the differences among short-term, medium-term and long- scheduling with suitable
example
Aspect Short-term Scheduling Medium-term Scheduling Long-term Scheduling
Manages process swapping Decides which jobs are admitted
Decides which process gets the
Definition in/out of memory. (1 into the system.
CPU next. (1 Mark)
Mark) (1 Mark)
Controls memory by Controls the system’s degree of
Allocates CPU time to ready
Function swapping processes. multiprogramming.
processes. (1 Mark)
(1 Mark) (1 Mark)
Runs as needed, less Runs infrequently when
Runs very frequently (on every
Frequency frequently than short-term. processes are submitted.
clock cycle). (1Mark)
(1 Mark) (1 Mark)
Aspect Short-term Scheduling Medium-term Scheduling Long-term Scheduling
Round Robin selects a process Swapping out a process Batch jobs being admitted to the
Example
for the CPU. (1Mark) waiting for I/O. (1 Mark) system. (1 Mark)
Ensures efficient CPU usage Optimizes memory usage Prevents system overload by
Importance and system responsiveness. and prevents overload. controlling process admission.
(1Mark) (1 Mark) (1 Mark)
13 a) Draw the diagram of segmentation memory management scheme and Explain its principle.
Diagram of Segmentation Memory Management (4 Marks)
Definition and Explanation of Segmentation( 2 marks)
Segmented Memory Organization (2 Marks)
Segment Table (2 Marks)
Address Translation (2 Marks)
Advantages (1 Mark)
Disadvantages (1 Mark)
13 b) i) Explain in detail about thrashing
Aspect Marks
Definition of Thrashing 2 Marks
Cause of Thrashing 2 Marks
Symptoms of Thrashing 1 Mark
Impact of Thrashing 1 Mark
Prevention and Solutions 1 Mark
ii) explain in detail about the allocation of kernel memory
Introduction 3marks
Techniques of Allocation 3marks
14. a) describe in detail file sharing and protection.
Introduction to File Sharing and Protection 2
File Sharing
Shared Access Modes (2 Marks).
b. File Sharing Models (2 Marks)
c. Challenges in File Sharing (1 Mark)
File Protection
Protection Mechanisms (3 Marks)
b. File Attributes and Permissions (2 Marks)
Challenges in File Protection (2 Marks)
14.b) i) explain free space management with neat example.
ii) explain the issues in designing a file system
Free Space Management 7
- Introduction 2
- Techniques (Bit Vector, Linked List, Grouping, Counting) 4
- Challenges 2
Issues in Designing a File System 5
- Data Consistency and Reliability 1
- Performance 1
- Space Management 1
- Security and Access Control 1
- Scalability 1
15 a) illustrate some existing SDK architecture implementation frameworks.
Introduction to SDKs 2
Examples of SDK Architecture 9
- Android SDK 4
- iOS SDK 2
- AWS SDK 2
- Unity SDK 2
Challenges in SDK Design2
b) generalize the importance of memory management in operating system
Introduction to Memory Management 3
Key Functions 7
- Allocation and Deallocation 2
- Process Isolation and Protection 2
- Virtual Memory Management 2
- Memory Sharing and Optimization 1
Challenges Addressed 3
- Fragmentation 1
- Deadlocks 1
- Performance Bottlenecks 1
PART-C
16.a) Explain in detail about linux architecture.
Introduction to Linux Architecture 3
Components of Linux Architecture 9
- Hardware Layer 1
- Kernel 3
- System Libraries 2
- System Utilities 2
- User Space 1
Features of Linux Architecture 1
16. b) compare the functions of media layer, service layer and core os layer
Feature Media Layer Service Layer Core OS Layer
Multimedia
Application-level services Hardware interaction and low-
Primary Role processing and
and APIs level services
rendering
Level of High (focused on user Medium (bridges user and
Low (direct hardware access)
Abstraction experience) hardware)
MediaCodec,
Examples Activity Manager, UIKit Linux Kernel, Darwin Kernel
OpenGL ES
Builds rich Enables app lifecycle
Developers' Use Provides foundational services
multimedia apps management
Introduction 3
Functions of Each Layer 9
- Media Layer 3
- Service Layer 3
- Core OS Layer 3
Comparison Table 2
