About OS

Question 1

What is the difference between a Monolithic and a Microkernel OS?

Answer 1

Monolithic: All systems and services on the OS are run with a single program in kernel mode.

Microkernel: Only essential services operate on the main kernel, otherwise different processes use different address spaces.

Question 2

Name a prominent monolithic operating system from the following: Linux, Windows, Mac.

Answer 2

Linux or Windows. Mac is on a hybrid structure.

Question 3

Name a prominent microkernel operating system from the following: Linux, Windows, Mac.

Answer 3

None of the given. Mac is on a hybrid structure, and the other two are monolithic.

Question 4

What is a CPU?

Answer 4

The computer’s “brain;” Controls other parts of the device. Stands for “Central Processing Unit.”

Question 5

What is memory built to do in computers?

Answer 5

Support processing through storage of instructions and data. Includes caching.

Question 6

What are L1, L2, and L3?

Answer 6

Three different levels of cache memory. L1 is the fastest but smallest, L3 is the slowest (faster than disc access though) and biggest.

Question 7

What is DRAM?

Answer 7

Dynamic Random Access Memory. Computer memory that stores data temporarily for CPU usage during applications. The main computer memory above disc space.

Question 8

What’s the difference between the group of L1, L2, and L3 and DRAM?

Answer 8

DRAM is main memory unit, while L1-3 are smaller caches.

Question 9

What is the Frontside bus?

Answer 9

Connects the CPU to main memory and speedy components.

Question 10

What is the Backside bus?

Answer 10

Connects the CPU to the L2 and L3 caches.

Question 11

Where is the L1 cache stored?

Answer 11

In the CPU itself; Runs at the same speed as the CPU.

Question 12

What is the system bus?

Answer 12

Connects the CPU to all system components.

Question 13

What is a HDD?

Answer 13

Hard Drive Disc. Physical Memory stored on a mechanical rotating disc. Good at sequential memory access.

Question 14

What is an SSD?

Answer 14

Solid-State Drive. Non-mechanical. Great at random access.

Question 15

What’s the main advantage of HDD’s over SSD’s?

Answer 15

Price.

Question 16

What is an NIC?

Answer 16

Network Interface Card. Interfaces with networks. Can interface with ethernet cables or wireless methods.

Question 17

What is a GPU?

Answer 17

Graphics Processing Unit. Handles display of image on a computer. Good at parallel processing.

Question 18

What is a TPU?

Answer 18

Hardware accelerator designed to optimize machine learning tasks (especially deep learning models).

Question 19

What is an FPGA?

Answer 19

Field-Programmable Gate Array. Type of semiconductor that can be programmed to handle specific functionality even after manufacturing. Pricey, but efficient.

Question 20

What does Moore’s Law outline?

Answer 20

Transistor capacity doubles every ~18 months, though this has hit a wall in 2003, instead people now focus on multi-core systems.

Question 21

When does a Bootstrapping Process start?

Answer 21

When power is initially applied.

Question 22

What does the OS Bootstrapping Process aim to accomplish?

Answer 22

Get the system ready to service user actions and needs.

Question 23

TRUE/FALSE: The bootstrapping process will only ever provide services to a user after the booting is completed.

Answer 23

FALSE: Services might be provided before booting completion (GUI display). Example: Connecting to the network for SSH use, or displaying a Splash screen before user can run programs.

Question 24

What are the three basic operating system duties?

Answer 24

Resource Management, Isolation & Security, and Scheduling.

Question 25

Describe an Operating System’s handling of Resource Management.

Answer 25

The initialization of physical resources, sharing and managing resources for the kernel and applications, abstraction of resources, and managing power and sleep status.

Question 26

Describe an Operating System’s handling of Isolation & Security.

Answer 26

Managing disjoint users and processes at the same time, making sure little degradation of other processes occurs when a large process happens at the same time (guarding against noisy neighbors), and securing data.

Question 27

Describe an Operating System’s handling of Scheduling.

Answer 27

Allowing many processes to share a set of cores, enabling the switch between processes (threading) with minimal latency, determining which process is run after one stops.

Question 28

TRUE/FALSE: Hard Realtime Systems are designed to optimize worst-case performance.

Answer 28

TRUE.

Question 29

TRUE/FALSE: Firm Realtime Systems care primarily about the amount of time a deadline is missed by.

Answer 29

FALSE: Firm Realtime Systems care primarily about the number and percentage of missed deadlines.

Question 30

TRUE/FALSE: An example of a Soft Realtime System is a router.

Answer 30

TRUE.