操作系统基础 | 80 问

注：机翻，未校。

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Operating System Interview Questions and Answers

操作系统面试问题及答案

Updated on February 22, 2025

Preparing for an interview about operating systems (OS) can be challenging. Knowing the basics of operating systems is essential to comprehending how hardware and software interact. Operating systems manage hardware resources, create a platform on which applications can run, and guarantee the system’s optimal performance.
准备关于 操作系统 (OS) 的面试可能会很具挑战性。了解操作系统的基础知识对于理解硬件与软件如何交互至关重要。操作系统管理硬件资源，创建应用程序可以运行的平台，并确保系统的最佳性能。

To help you better, this guide covers important operating system interview questions, providing insight into preparing fully and ensuring that you ace your interview. So, let’s understand the operating system and their important interview questions.
为了更好地帮助你，本指南涵盖了重要的操作系统面试问题，提供全面准备的见解，确保你面试成功。那么，让我们来了解操作系统及其重要的面试问题。

Why operating system is important?

为什么操作系统很重要？

Any computer system needs an operating system which constitutes its fundamental structure. An operating system enables effective program operation through its control of hardware resources. The computer becomes nonfunctional when an operating system is absent since it requires an interface which enables user interactions with hardware. The OS ensures application and process resource allocation together with task management that helps prevent conflicts.
任何计算机系统都需要一个操作系统，它是计算机系统的基本结构。操作系统通过控制硬件资源来实现程序的有效运行。当缺少操作系统时，计算机将无法正常工作，因为它需要一个接口来实现用户与硬件的交互。操作系统确保应用程序和进程的资源分配以及任务管理，从而帮助避免冲突。

Why are the Basic Functions of Operating Systems Essential?

操作系统的最基本功能为什么至关重要？

The functioning efficiency of a computer relies on basic features native to its operating system. Every program requires sufficient memory from the operating system to run effectively. An operating system controls processing assignments through resource distribution while prioritizing running programs and regulating the Central Processing Unit.
计算机的功能效率依赖于其操作系统的基本功能。每个程序都需要足够的内存才能有效运行。操作系统通过资源分配来控制处理任务，同时优先处理正在运行的程序并调节中央处理单元。

The operating system handles all user input and screen output operations through its management system. Operating systems accomplish this task by finding methods to unite computer hardware and software elements into a stable user interface that enables computer interaction. Through its user interface, the operating system helps users to execute commands while providing access to files and managing system resources.
操作系统通过其管理系统处理所有用户输入和屏幕输出操作。操作系统通过寻找方法将计算机硬件和软件元素结合成一个稳定的用户界面来完成这项任务，从而实现计算机交互。通过其用户界面，操作系统帮助用户执行命令，同时提供对文件的访问并管理系统资源。

Basic-level Operating System Interview Questions

基础级别的操作系统面试问题

1. What is an operating system?

1. 什么是操作系统？

An operating system is a program that manages computer hardware and software resources. The operating system operates between the users and programs on one side and the computer’s hardware devices on the other side by providing the common use of computer programs. Some examples are Windows, macOS or Linux.
操作系统是管理计算机硬件和软件资源的程序。操作系统位于用户和程序与计算机硬件设备之间，通过提供计算机程序的通用使用。一些例子包括 Windows、macOS 或 Linux。

2. What are the main functions of an operating system?

2. 操作系统的主要功能是什么？

The main functions of an operating system include:
操作系统的主要功能包括：

Function 功能	Description 描述
Process Management 进程管理	Manages the execution of processes, including multitasking and scheduling. 管理进程的执行，包括多任务处理和调度。
Memory Management 内存管理	Allocates and manages the computer’s memory resources. 分配和管理计算机的内存资源。
File System Management 文件系统管理	Controls the creation, deletion, and access of files and directories. 控制文件和目录的创建、删除和访问。
Device Management 设备管理	Manages device communication via drivers. 通过驱动程序管理设备通信。
Security and Access Control 安全和访问控制	Protects data and resources from unauthorised access. 保护数据和资源免受未经授权的访问。

3. What are the differences between multiprogramming, multitasking, and multiprocessing?

3. 多道程序、多任务和多处理之间的区别是什么？

Feature 特征	Multiprogramming 多道程序	Multitasking 多任务	Multiprocessing 多处理
Definition 定义	Multiple programs are loaded in memory, and the CPU is switched between them to increase efficiency. 多个程序被加载到内存中，CPU 在它们之间切换以提高效率。	Multiple tasks are performed concurrently by switching rapidly between them. 通过快速在它们之间切换，多个任务同时执行。	Multiple processors (CPUs) are used to perform tasks simultaneously. 使用多个处理器 (CPU) 同时执行任务。
Objective 目标	Maximise CPU utilisation 最大化 CPU 利用率	Provide responsive interaction 提供响应式交互	Improve performance and reliability by parallel processing 通过并行处理提高性能和可靠性
Example 示例	Running a batch job while a user program runs 运行用户程序的同时运行批处理作业	Running a web browser and a text editor at the same time 同时运行网络浏览器和文本编辑器	Running multiple complex computations or server processes concurrently 同时运行多个复杂计算或服务器进程 concurrently
Execution 执行	Single CPU switches between programs 单个 CPU 在程序之间切换	Single CPU switches between tasks frequently 单个 CPU 频繁地在任务之间切换	Multiple CPUs execute different processes simultaneously 多个 CPU 同时执行不同进程
Complexity 复杂性	Moderate 中等	Moderate 中等	High 高
Resource Usage 资源使用	Efficient memory usage, high CPU utilisation 高效的内存使用，高 CPU 利用率	High CPU and memory usage 高 CPU 和内存使用	High CPU usage with efficient distribution of tasks 高 CPU 使用，高效分配任务

4. What is a context switch in the Operating System?

4. 什么是操作系统中的上下文切换？

Context switch refers to a process whereby CPU state storage is done so that multiple processes are enabled to share a single CPU resource. When context switching occurs, it enables the OS to jump from one task to another, ensuring efficiency in multitasking or execution of other critical functions within a PC system. During the context-switching process, information like registers or program counters would be saved into the process table before being loaded into the new state of the next running process.
上下文切换是指为了使多个进程能够共享单个 CPU 资源而进行的 CPU 状态存储的过程。当发生上下文切换时，它使操作系统能够从一个任务跳转到另一个任务，确保在多任务处理或执行其他关键功能时的效率。在上下文切换过程中，寄存器或程序计数器等信息将被保存到进程表中，然后加载到下一个运行进程的新状态中。

5. What is a process and process table?

5. 什么是进程和进程表？

A process is a program in execution, including its code, data, and resources. It is an active entity with a unique Process ID (PID). The process table is a data structure maintained by the operating system that keeps track of all the processes. It contains information such as the process state, PID, program counter, and memory allocation.
进程是正在执行的程序，包括其代码、数据和资源。它是一个具有唯一进程 ID（PID）的活动实体。进程表是由操作系统维护的数据结构，用于跟踪所有进程。它包含进程状态、PID、程序计数器和内存分配等信息。

Field 字段	Description 描述
Process ID (PID) 进程 ID (PID)	Unique identifier for the process 进程的唯一标识符
Process State 进程状态	Current state (running, waiting) 当前状态（运行中、等待中）
Program Counter 程序计数器	Address of the next instruction 下一条指令的地址
Memory Allocation 内存分配	Memory used by the process 进程使用的内存

6. What is Thread?

6. 什么是线程？

A thread is the most basic process unit that the CPU can schedule and run. It is an execution path that accesses the process’s resources, including memory and open files. Several threads may be present in one process, allowing for parallelism and effective task management.
线程是 CPU 可以调度和运行的最基本进程单元。它是访问进程资源（包括内存和打开的文件）的执行路径。一个进程中可能存在多个线程，从而实现并行性和有效的任务管理。

7. Explain the difference between a process and a thread.

7. 解释进程和线程之间的区别。

Feature 特征	Process 进程	Thread 线程
Definition 定义	An independent program in execution. 一个独立的正在执行的程序。	A lightweight sub-process or task within a process. 一个进程内的轻量级子进程或任务。
Memory 内存	Each process has its own memory space. 每个进程有自己的内存空间。	Threads share the same memory space within a process. 线程共享同一进程内的内存空间。
Resource Overhead 资源开销	High, as each process has its own resources. 高，因为每个进程有自己的资源。	Low, as threads share resources of the process. 低，因为线程共享进程的资源。
Communication 通信	Inter-process communication (IPC) is needed. 需要进程间通信 (IPC)。	Direct communication through shared memory. 通过共享内存直接通信。
Creation Time 创建时间	Longer due to resource allocation. 由于资源分配，时间较长。	Shorter, as resources are already allocated. 时间较短，因为资源已经分配。

8. Describe the process of process creation and termination.

8. 描述进程创建和终止的过程。

Process Creation:
进程创建：

• Forking: The operating system creates a new process by duplicating an existing one.

  Forking: 操作系统通过复制一个现有进程来创建一个新进程。

• Initialization: The new process is initialised with a unique Process ID (PID).

  Initialization: 新进程被分配一个唯一的进程 ID (PID)。

• Resource Allocation: Memory and other resources are allocated.

  Resource Allocation: 分配内存和其他资源。

• Execution: The new process starts executing, either continuing from the point of the original process or beginning a new program.

  Execution: 新进程开始执行，要么从原始进程的点继续，要么开始一个新的程序。

Process Termination:
进程终止：

• Normal Exit: The process completes its execution and calls an exit system call.

  Normal Exit: 进程完成其执行并调用退出系统调用。

• Error Exit: The process encounters an error and is terminated.

  Error Exit: 进程遇到错误并被终止。

• Forced Termination: Another process or the OS forces the process to terminate using a kill command.

  Forced Termination: 另一个进程或操作系统使用杀死命令强制终止该进程。

• Resource Deallocation: The OS reclaims the resources used by the process.

  Resource Deallocation: 操作系统回收该进程使用的资源。

9. What is the difference between preemptive and non-preemptive scheduling?

9. 抢占式调度和非抢占式调度有什么区别？

Feature 特征	Preemptive Scheduling 抢占式调度	Non-Preemptive Scheduling 非抢占式调度
Definition 定义	The OS can interrupt and switch tasks. 操作系统可以中断并切换任务。	The OS waits for the running task to finish. 操作系统等待正在运行的任务完成。
Control 控制	The OS has control over task switching. 操作系统控制任务切换。	The running task has control over its completion. 正在运行的任务控制其完成。
Response Time 响应时间	Lower, due to quick task switching. 更低，因为任务切换迅速。	Higher, as each task runs to completion. 更高，因为每个任务都运行到完成。
Complexity 复杂性	Higher due to handling interruptions. 更高，因为需要处理中断。	Lower, as tasks run without interruptions. 更低，因为任务运行时不被打断。
Example 示例	Round Robin, Shortest Remaining Time First (SRTF) 轮询、最短剩余时间优先 (SRTF)	First-Come, First-Served (FCFS), Shortest Job Next (SJN) 先来先服务 (FCFS)、最短作业优先 (SJN)

10. What is a system call, and in what ways does it differ from a normal function call?

10. 什么是系统调用，它与普通函数调用有什么不同？

System Calls:
系统调用：

• In computing, a system call is the programmatic way a computer program requests a service from the operating system on which it is executed.

  在计算中，系统调用是计算机程序在其上执行的操作系统请求服务的程序化方式。

• They execute in kernel mode, granting them access to resources and hardware vital to a system.

  它们在内核模式下执行，从而获得对系统至关重要的资源和硬件的访问权限。

Normal Function Calls:
普通函数调用：

• Normal function calls are user-defined or library functions that execute within the user program’s context.

  普通函数调用是用户定义的或库函数，在用户程序的上下文中执行。

• They run in user mode and do not have direct access to hardware or kernel resources.

  它们在用户模式下运行，没有直接访问硬件或内核资源的权限。

Feature 特征	System Calls 系统调用	Normal Function Calls 普通函数调用
Access Level 访问级别	Kernel mode 内核模式	User mode 用户模式
Purpose 目的	Request services from the OS 请求操作系统的服务	Perform specific tasks within a program 在程序内执行特定任务
Execution Overhead 执行开销	Higher, due to context switching to kernel 更高，因为需要切换到内核上下文	Lower, executed within the same user space 更低，在相同的用户空间内执行
Examples 示例	open(), read(), write() open()、read()、write()	printf(), strlen(), sort() printf()、strlen()、sort()

11. Differentiate the kernel mode and user mode.

11. 区分内核模式和用户模式。

Feature 特征	Kernel Mode 内核模式	User Mode 用户模式
Access Level 访问级别	Full access to all system resources 完全访问所有系统资源	Limited access to system resources 有限访问系统资源
Privileges 特权	High, can execute privileged instructions 高，可以执行特权指令	Low, cannot execute privileged instructions 低，不能执行特权指令
Purpose 目的	Execute OS code and manage hardware 执行操作系统代码和管理硬件	Execute application code 执行应用程序代码
Stability 稳定性	Less stable, errors can crash the system 较不稳定，错误可能导致系统崩溃	More stable, errors are confined to the application 更稳定，错误仅限于应用程序
Example 示例	System calls, device drivers 系统调用，设备驱动程序	User applications, standard library calls 用户应用程序，标准库调用

12. What is Thrashing?

12. 什么是抖动？

Thrashing refers to constantly swapping pages in and out of memory while the actual processes are not being executed because the system is busy. It normally results from a shortage in RAM, which degrades the performance of a system.
抖动是指系统忙于不断地将页面调入和调出内存，而实际进程并未被执行。它通常由 RAM 不足引起，从而降低了系统的性能。

13. What are the benefits of multithreaded programming?

13. 多线程编程的好处是什么？

Benefit 好处	Description 描述
Responsiveness 响应性	Improves application responsiveness by allowing background tasks to run concurrently. 通过允许后台任务并发运行，提高应用程序的响应性。
Resource Sharing 资源共享	Threads within a process share resources, which is more efficient than separate processes. 线程共享同一进程内的资源，这比单独的进程更有效。
Scalability 可扩展性	Utilises multiprocessor architectures more effectively by running threads in parallel. 通过并行运行线程，更有效地利用多处理器架构。
Simplified Program Structure 简化的程序结构	Easier to manage multiple tasks within a single application context. 在单一应用程序上下文中更容易管理多个任务。

14. What is Buffer?

14. 什么是缓冲区？

Any temporary storage section used as an intermediate in withholding data during its movement from one location to another is known as a buffer. Buffers are used to manage data streams and improve data transfer efficiency between devices or processes.
任何用作在数据从一个位置移动到另一个位置时的中间临时存储部分都称为缓冲区。缓冲区用于管理数据流并提高设备或进程之间的数据传输效率。

15. What is Demand paging?

15. 什么是请求分页？

A graphical user interface, or GUI, is a computer system where a human interacts with the computers using windows, icons, buttons, and menus rather than typing command lines. GUIs make software more user-friendly and accessible by offering intuitive graphical controls enabling users to accomplish their intended goals easily.
图形用户界面（GUI）是一种计算机系统，用户通过窗口、图标、按钮和菜单与计算机交互，而不是输入命令行。GUI 通过提供直观的图形控件使软件更易于使用和访问，使用户能够轻松实现其目标。

16. What are the different states of the process?

16. 进程的不同状态有哪些？

State 状态	Description 描述
New 新建	The process is being created. 进程正在被创建。
Ready 就绪	The process is waiting to be assigned to a CPU. 进程正在等待被分配给 CPU。
Running 运行	The CPU is currently executing the process. CPU 正在执行该进程。
Waiting 等待	The process is waiting for an event (e.g., I/O completion). 进程正在等待一个事件（例如，I/O 完成）。
Terminated 终止	The process has finished execution or has been terminated by the OS. 进程已经完成执行或被操作系统终止。
Suspended 挂起	The process is temporarily stopped, possibly swapped out to disk. 进程暂时停止，可能被交换到磁盘。

17. What are the 5 important concepts of OS?

17. 操作系统的五个重要概念是什么？

• Process Management: Dealing with creating, scheduling, and destroying processes.
  进程管理：处理进程的创建、调度和销毁。
• Memory Management: Handling the allocation and deallocation of memory space.
  内存管理：处理内存空间的分配和回收。
• File System Management: Data storage, organization, and retrieval on storage devices.
  文件系统管理：在存储设备上进行数据存储、组织和检索。
• Security and Access Control: Guarding information and resources against unauthorized access.
  安全和访问控制：防止未经授权的访问，保护信息和资源。
• Device Management: Managing and regulating hardware devices by drivers.
  设备管理：通过驱动程序管理硬件设备。

18. What are the different scheduling algorithms?

18. 不同的调度算法有哪些？

Scheduling Algorithm 调度算法	Description 描述
First-Come, First-Served (FCFS) 先来先服务 (FCFS)	Processes are executed in the order they arrive. 按到达顺序执行进程。
Shortest Job Next (SJN) 最短作业优先 (SJN)	Processes with the shortest execution time are scheduled next. 执行时间最短的进程被优先调度。
Priority Scheduling 优先级调度	Processes are scheduled based on priority levels. 根据优先级调度进程。
Round Robin (RR) 轮询 (RR)	Each process gets a fixed time slice in a cyclic order. 每个进程按循环顺序获得固定时间片。
Multilevel Queue Scheduling 多级队列调度	Processes are divided into multiple queues based on their priority and type. 根据进程的优先级和类型将进程分配到多个队列中。
Shortest Remaining Time First (SRTF) 最短剩余时间优先 (SRTF)	A preemptive version of SJN, where the process with the least remaining time is scheduled. SJN 的抢占式版本，剩余时间最少的进程被优先调度。

19. Describe the objective of multiprogramming.

19. 描述多道程序的目标。

The highest utilisation of the CPU by running several processes together is the goal of multiprogramming. In that case, it always keeps the CPU busy executing any process to enhance efficiency.
通过同时运行多个进程以最大化 CPU 利用率是 多道程序 的目标。在这种情况下，它始终让 CPU 忙于执行任何进程以提高效率。

20. What problem do we face in computer systems without OS?

20. 没有操作系统，计算机系统会面临什么问题？

Without an OS, computer systems face several problems, including:

• Resource Management: No centralised management of CPU, memory, and I/O devices.
  资源管理：没有对 CPU、内存和 I/O 设备的集中管理。
• User Interface: Lack of a user-friendly interface to interact with hardware.
  用户界面：缺乏与硬件交互的用户友好界面。
• Security: No protection mechanisms to prevent unauthorised access.
  安全性：没有防止未经授权访问的保护机制。
• Program Execution: Difficulties in loading, executing, and managing multiple programs.
  程序执行：加载、执行和管理多个程序存在困难。

21. What is FCFS?

21. 什么是先来先服务（FCFS）？

First-Come, First-Served (FCFS) scheduling algorithm executes processes according to their arrival order in the ready queue. It has an easy validation process because it only needs proportionate waiting times, but in some scenarios, it results in a convoy effect, causing slow response due to long tasks with small ones behind them.
先来先服务（FCFS）调度算法根据进程在就绪队列中的到达顺序执行进程。它的验证过程简单，因为它只需要按比例的等待时间，但在某些情况下，它会导致车队效应，由于长任务后面跟着短任务，从而导致响应缓慢。

22. What is the RR scheduling algorithm?

22. 什么是轮询（RR）调度算法？

Round Robin (RR) Scheduling Algorithm allocates a fixed time slot, (Time Quantum) for every process in the ready queue. The CPU cycles through processes, giving each one a turn to execute for quantum duration. This ensures fairness, leading to better response time, but may result in massive context-switching overheads.
轮询（RR）调度算法为就绪队列中的每个进程分配一个固定时间片（时间量子）。CPU 循环处理进程，每个进程都有机会在量子时间内执行。这确保了公平性，从而提高了响应时间，但可能会导致大量的上下文切换开销。

23. What is cache?

23. 什么是缓存？

Caching is the process of putting frequently used data in a temporary storage area to make access to data more rapid. This latency-reducing and performance-enhancing function can be found either at higher or lower levels of computing.
缓存是将经常使用的数据放入临时存储区域的过程，以便更快地访问数据。这种减少延迟和提高性能的功能可以在计算的高层或低层找到。

24. What is the functionality of an Assembler?

24. 汇编器的功能是什么？

An assembler translates assembly language into machine code that a computer’s CPU can directly execute. This allows us to use mnemonics and symbols that are later translated to the corresponding binary opcode and addresses, making low-level programming possible.
汇编器将汇编语言翻译成计算机 CPU 可以直接执行的机器代码。这使我们能够使用稍后被翻译成相应二进制操作码和地址的助记符和符号，从而使低级编程成为可能。

25. What does GUI mean?

25. GUI 是什么意思？

A graphical user interface, or GUI, is a computer system where a human interacts with the computers using windows, icons, buttons, and menus rather than typing command lines. GUIs make software more user-friendly and accessible by offering intuitive graphical controls that enable users to easily and painlessly accomplish their intended goals.
图形用户界面（GUI）是一种计算机系统，用户通过窗口、图标、按钮和菜单与计算机交互，而不是输入命令行。GUI 通过提供直观的图形控件使软件更易于使用和访问，使用户能够轻松且无痛地实现其目标。

26. What is a pipe? When Is It Used?

26. 什么是管道？何时使用它？

Pipes use unidirectional flow when passing information from one process to another in inter-process communication. Pipes are commonly used for connecting the output from one process to the input of another thus enabling sharing of data and task chaining efficiently.
在进程间通信中，管道用于将信息从一个进程传递到另一个进程的单向流动。管道通常用于将一个进程的输出连接到另一个进程的输入，从而高效地实现数据共享和任务链。

27. What are the goals of CPU scheduling?

27. CPU 调度的目标是什么？

Goal 目标	Description 描述
Fairness 公平性	Ensure all processes get a fair share of CPU time. 确保所有进程都能公平地获得 CPU 时间。
Efficiency 效率	Maximise CPU utilisation and minimise idle time. 最大化 CPU 利用率并最小化空闲时间。
Response Time 响应时间	Minimise the time from submission to the first response. 最小化从提交到首次响应的时间。
Turnaround Time 周转时间	Minimise the total time from submission to completion of a process. 最小化从提交到进程完成的总时间。
Throughput 吞吐量	Maximise the number of processes completed per unit time. 最大化单位时间内完成的进程数量。
Predictability 可预测性	Ensure consistent and predictable process performance. 确保进程性能的一致性和可预测性。

28. Write the name of synchronisation techniques.

28. 写出同步技术的名称。

• Mutexes (Mutual Exclusion)
  互斥锁（互斥）
• Semaphores
  信号量
• Monitors
  监视器
• Spinlocks
  自旋锁
• Barriers
  屏障
• Condition Variables
  条件变量

29. Define the term Bit-Vector.

29. 定义术语位向量。

A bit vector is a vector in which each element is a bit – thus, its value is either 0 or 1. In most vectors, each element is in a distinct address in memory and can be manipulated independently from the rest of the elements, and we also hope to be able to perform “vector operations” that treat all elements uniformly. One application of bit vectors is in encoding information in a computer system; for example, numbers are represented using bit vectors.
位向量是一个向量，其中每个元素都是一个位——因此，其值要么是 0，要么是 1。在大多数向量中，每个元素在内存中都有一个不同的地址，并且可以独立于其他元素进行操作，我们还希望能够执行“向量操作”，这些操作将所有元素视为统一的。位向量的一个应用是在计算机系统中编码信息；例如，数字使用位向量表示。

30. Write the names of different operations on the file.

30. 写出文件的不同操作名称。

• Create
  创建
• Open
  打开
• Read
  读取
• Write
  写入
• Close
  关闭
• Delete
  删除
• Append
  追加
• Rename
  重命名

31. What is rotational latency?

31. 什么是旋转延迟？

Rotational latency is the delay experienced while waiting for the desired disk sector to rotate under the read/write head. It is a component of the total disk access time, along with seek time and data transfer time.
旋转延迟是在等待所需的磁盘扇区旋转到读/写磁头下方时所经历的延迟。它是总磁盘访问时间的一部分，与寻道时间和数据传输时间一起。

32. What is a File allocation table?

32. 文件分配表是什么？

A File Allocation Table (FAT) is a file system structure used to keep track of the clusters (storage units) on a disk. It maps each file to its corresponding clusters, allowing the system to locate and manage files efficiently. FAT is used in various file systems, including FAT12, FAT16, and FAT32.
文件分配表（FAT）是一种文件系统结构，用于跟踪磁盘上的簇（存储单元）。它将每个文件映射到其对应的簇，使系统能够高效地定位和管理文件。FAT 用于各种文件系统，包括 FAT12、FAT16 和 FAT32。

33. How to recover from a deadlock?

33. 如何从死锁中恢复？

Deadlock Recovery Method 死锁恢复方法	Description 描述
Process Termination 进程终止	Terminate one or more processes involved in the deadlock. 终止一个或多个参与死锁的进程。
Resource Preemption 资源抢占	Temporarily take resources away from processes and relocate them. 临时从进程那里拿走资源并重新分配。
Rollback 回滚	Roll back one or more processes to a safe state before the deadlock occurred. 将一个或多个进程回滚到死锁发生之前的安全状态。
Deadlock Detection and Resolution 死锁检测和解决	Continuously check for deadlocks and resolve them using one of the above methods. 持续检测死锁并使用上述方法之一解决。

34. Definition of real-time systems

34. 实时系统的定义

Real-time systems refer to computer systems that must respond quickly and precisely at times dictated by external events. Such systems are meant for processing data within hard constraints about timing; they are popularly used in areas like embedded systems, industrial control, mission-critical tasks, etc.
实时系统是指必须在外部事件决定的时间内快速且精确地做出响应的计算机系统。这些系统用于在严格的时间限制内处理数据；它们通常用于嵌入式系统、工业控制、关键任务等领域。

35. What is seek time?

35. 什么是寻道时间？

Seek time is the duration that a hard disk drive (HDD) takes to find and move a read or write head from one track to another where necessary data has been stored. It contributes significantly to the performance of hard disk access as its value forms a part of the total disk access time.
寻道时间是硬盘驱动器（HDD）找到并移动读/写磁头从一个磁道到另一个磁道所需的时间，在那里存储了必要的数据。它对硬盘访问的性能有显著影响，因为它的值构成了总磁盘访问时间的一部分。

Intermediate-level Operating System Interview Questions

中级操作系统面试问题

36. What are the different RAID levels?

36. 不同的 RAID 级别有哪些？

RAID Level RAID 级别	Description 描述
RAID 0	Data striping without redundancy improves performance but no fault tolerance. 数据条带化但无冗余，提高了性能但没有容错能力。
RAID 1	Data mirroring duplicates data on two disks for fault tolerance. 数据镜像在两个磁盘上复制数据以实现容错。
RAID 5	Data striping with distributed parity provides fault tolerance and efficient storage. 数据条带化与分布式奇偶校验提供容错和高效的存储。
RAID 6	Similar to RAID 5 but with an extra parity block, allows for up to two disk failures. 类似于 RAID 5，但增加了一个奇偶校验块，允许最多两个磁盘故障。
RAID 10	Combines RAID 1 and RAID 0, mirroring and striping for high performance and fault tolerance. 结合了 RAID 1 和 RAID 0，镜像和条带化以实现高性能和容错。
RAID 50	Combines RAID 5 and RAID 0, providing fault tolerance and high performance. 结合了 RAID 5 和 RAID 0，提供容错和高性能。
RAID 60	Combines RAID 6 and RAID 0, offering enhanced fault tolerance and performance. 结合了 RAID 6 和 RAID 0，提供增强的容错和性能。

37. Explain Banker’s algorithm.

37. 解释银行家算法。

Banker’s algorithm is a deadlock-avoidance algorithm. It allocates resources based on the resource needs of each process and then determines if the state is safe in terms of deadlock avoidance. If the system remains safe after allocation, the resources are allocated; otherwise, make it wait.
银行家算法 是一种死锁避免算法。它根据每个进程的资源需求分配资源，然后确定该状态是否在死锁避免方面是安全的。如果分配后系统仍然安全，则分配资源；否则，使其等待。

38. What are the Benefits of Dynamic Loading Concerning Better Memory Space Utilisation?

38. 动态加载在更好地利用内存空间方面有什么好处？

Dynamic loading loads a program’s parts into memory only when needed, rather than loading the entire program at once. This reduces the amount of RAM consumed by any specific program at any given moment and allows more simultaneous loading of programs.
动态加载仅在需要时才将程序的部分加载到内存中，而不是一次性加载整个程序。这减少了任何特定程序在任何给定时刻消耗的 RAM 量，并允许同时加载更多的程序。

39. Explain the main difference between logical and physical address space.

39. 解释逻辑地址空间和物理地址空间的主要区别。

Feature 特征	Logical Address Space 逻辑地址空间	Physical Address Space 物理地址空间
Definition 定义	The address generated by the CPU during program execution. CPU 在程序执行期间生成的地址。	The actual address in the memory unit. 内存单元中的实际地址。
View 视图	User view of the memory (virtual address). 用户对内存的视图（虚拟地址）。	Hardware view of the memory. 硬件对内存的视图。
Access 访问	Managed by the OS using memory management techniques. 由操作系统使用内存管理技术进行管理。	Directly accessed by the memory hardware. 直接由内存硬件访问。

40. What are overlays?

40. 什么是覆盖？

Overlays are mechanisms used to work around physical memory limitations within systems by loading only relevant instructions and data segments into memory. Whenever a different portion of this program is needed, the current overlay is replaced with the required one. Using this technique, large-sized applications can run on low-memory systems without compromising their functionality.
覆盖是用于解决系统内物理内存限制的机制，通过仅将相关的指令和数据段加载到内存中。每当需要程序的不同部分时，当前的覆盖将被替换为所需的覆盖。使用这种技术，大型应用程序可以在低内存系统上运行，而不会损害其功能。

41. What is fragmentation?

41. 什么是碎片化？

Fragmentation occurs when memory is allocated and deallocated in a way that leaves small, unusable gaps. It comes in two types:

Type 类型	Description 描述
Internal Fragmentation 内部碎片化	Unused memory within allocated regions, due to the allocated size being larger than needed. 由于分配的大小大于所需大小，分配区域内未使用的内存。
External Fragmentation 外部碎片化	Unused memory between allocated regions, due to varying sizes of memory allocation and deallocation. 由于内存分配和回收的大小不一，在分配区域之间未使用的内存。

42. What is the basic function of paging?

42. 分页的基本功能是什么？

It is a memory management technique that divides a process’s memory into pages that have fixed sizes and physical memory into frames with similar sizes. The functionality of paging provides a way to connect virtual addresses to physical addresses, thereby making it possible for computer systems to use memory in an efficient manner without the need for contiguous allocation.
分页是一种内存管理技术，它将进程的内存划分为固定大小的页面，将物理内存划分为大小相似的帧。分页的功能提供了将虚拟地址连接到物理地址的方法，从而使计算机系统能够在不需要连续分配的情况下高效地使用内存。

43. How does swapping result in better memory management?

43. 交换如何实现更好的内存管理？

Swapping improves memory management by temporarily moving inactive processes from the main memory to a storage device (swap space). This frees up RAM for active processes, allowing the system to handle more processes concurrently and improve overall performance. When the swapped-out process is needed again, it is swapped back into memory.
交换通过将不活动的进程从主内存临时移动到存储设备（交换空间）来改善内存管理。这为活动进程释放了 RAM，使系统能够同时处理更多的进程并提高整体性能。当需要再次使用交换出去的进程时，它将被交换回内存。

44. What is the Direct Access Method?

44. 什么是直接访问方法？

The Direct Access Method allows data to be read or written directly to a specific location on a storage device without sequentially accessing preceding data. This method is commonly used in disk drives where each block or sector has a unique address, enabling quick access to data and improving performance for large data sets.
直接访问方法允许直接在存储设备的特定位置读取或写入数据，而无需顺序访问前面的数据。这种方法通常用于磁盘驱动器，其中每个块或扇区都有一个唯一的地址，能够快速访问数据并提高大型数据集的性能。

45. When does thrashing occur?

45. 抖动何时发生？

Generally, thrashing occurs when the computer system spends more of its time paging is swapping data in and out of memory rather than actually executing any processes. This can be due to a shortage of available RAM, given that heavy paging drastically reduces the performance of the system.
通常，抖动发生在计算机系统花费更多时间进行分页（将数据在内存中调入调出）而不是实际执行任何进程时。这可能是由于可用 RAM 不足，因为大量的分页会显著降低系统的性能。

46. What are interrupts?

46. 什么是中断？

Interrupts mean signals that are sent to CPU by software or hardware, indicating an event which needs immediate attention. When an interrupt takes place, the CPU temporarily stops executing current instructions and transfers control to an interrupt handler to address the event. After handling the interrupt, the CPU resumes its normal execution.
中断是指由软件或硬件发送给 CPU 的信号，表示需要立即关注的事件。当中断发生时，CPU 会暂时停止执行当前指令，并将控制权转移到中断处理程序以处理该事件。处理完中断后，CPU 恢复正常执行。

47. What is Preemptive Multitasking?

47. 什么是抢占式多任务处理？

Preemptive multitasking is one of the methods used to schedule a central processing unit. In this technique, the operating system allows CPU time for the processes and can forcefully remove a process from the CPU when it is actually allotting another process’s time. This technique guarantees an equal share of CPU time for all the processes and enhances the response of this system by disallowing one process to hold the CPU fully.
抢占式多任务处理是用于调度中央处理单元的方法之一。在这种技术中，操作系统允许进程使用 CPU 时间，并且可以在实际分配另一个进程的时间时，强制将一个进程从 CPU 中移除。这种技术保证了所有进程都能平等分享 CPU 时间，并通过不允许一个进程完全占用 CPU 来提高系统的响应能力。

48. What are the advantages of semaphores?

48. 信号量的优点是什么？

Advantage 优点	Description 描述
Synchronisation 同步	Semaphores help synchronise access to shared resources, preventing race conditions. 信号量有助于同步对共享资源的访问，防止竞争条件。
Mutual Exclusion 互斥	Ensures that only one process accesses a critical section at a time. 确保一次只有一个进程可以访问临界区。
Simplicity 简单性	Provides a simple mechanism for managing concurrent processes. 为管理并发进程提供了一个简单的机制。
Flexibility 灵活性	Can be used for both signalling and resource counting, making them versatile. 可以用于信号传递和资源计数，使它们具有通用性。
Efficiency 效率	Reduces the need for busy waiting, as processes can be blocked until the semaphore is available. 减少了忙等待的需求，因为进程可以在信号量可用之前被阻塞。

49. IPC is what?

49. IPC 是什么？

Inter-process Communication (IPC) is a method through which several processes communicate with each other and, at the same time, synchronise their actions. Some of these are message passing, shared memory, semaphores, pipes, etc., that allow sharing of the data and thus synchronisation amongst all these diverse processes.
进程间通信（IPC）是一种方法，通过该方法，多个进程可以相互通信，同时同步它们的动作。其中一些方法包括消息传递、共享内存、信号量、管道等，它们允许共享数据，从而在所有这些不同的进程之间实现同步。

50. What is a Batch Operating System?

50. 什么是批处理操作系统？

A Batch Operating System processes batches of jobs with similar requirements together without user interaction during execution. Jobs are collected, grouped, and processed sequentially, improving resource utilisation and throughput.
批处理操作系统会一起处理具有相似需求的作业批次，执行过程中无需用户交互。作业被收集、分组并按顺序处理，提高了资源利用率和吞吐量。

51. What are starvation and ageing in the OS?

51. 操作系统中的饥饿和老化是什么？

Concept 概念	Description 描述
Starvation 饥饿	Occurs when a process waits indefinitely for resources due to continuous resource allocation to other processes. 由于持续将资源分配给其他进程，一个进程无限期地等待资源。
Ageing 老化	A technique used to prevent starvation by gradually increasing the priority of waiting processes over time. 通过逐渐提高等待进程的优先级来防止饥饿的技术。

52. What is PCB?

52. 什么是进程控制块（PCB）？

A Process Control Block (PCB) is a data structure used by the operating system to store information about a process. The PCB contains details such as:

Field 字段	Description 描述
Process ID (PID) 进程 ID (PID)	Unique identifier for the process 进程的唯一标识符
Process State 进程状态	Current state of the process (e.g., running, waiting) 进程的当前状态（例如，运行中、等待中）
Program Counter 程序计数器	Address of the next instruction to execute 下一条要执行的指令的地址
CPU Registers CPU 寄存器	Current values of the CPU registers CPU 寄存器的当前值
Memory Management 内存管理	Information about memory allocation 内存分配的信息

53. When is a system in a safe state?

53. 系统何时处于安全状态？

A system is in a safe state if there exists a sequence of processes such that each process can be allocated the necessary resources and complete its execution without causing a deadlock. In a safe state, the system can avoid deadlock by careful resource allocation.
如果存在一个进程序列，使得每个进程都可以被分配必要的资源并完成其执行而不导致死锁，那么系统就处于安全状态。在安全状态下，系统可以通过谨慎的资源分配来避免死锁。

54. What is Cycle Stealing?

54. 什么是周期窃取？

Cycle stealing entails Direct Memory Access (DMA) controllers transferring data between memory and I/O devices directly by ‘stealing’ CPU cycles. During cycle stealing, the DMA controller gains access to memory while momentarily halting the operation of the Central Processing Unit, thereby reducing its workloads in many cases related to data transfer operations.
周期窃取是指直接内存访问（DMA）控制器通过“窃取”CPU 周期直接在内存和 I/O 设备之间传输数据。在周期窃取期间，DMA 控制器在暂时停止中央处理单元的操作的同时获得对内存的访问，从而在许多与数据传输操作相关的案例中减少了其工作负载。

55. What are Trap and Trapdoor?

55. 什么是陷阱和后门？

Concept 概念	Description 描述
Trap 陷阱	A trap is a software-generated interrupt caused by an error or specific condition in a program, triggering a switch to the OS to handle the event. 陷阱是由程序中的错误或特定条件引起的软件生成的中断，触发切换到操作系统以处理该事件。
Trapdoor 后门	A trapdoor (or backdoor) is a hidden method of bypassing normal authentication or security controls, often used maliciously to gain unauthorised access to a system. 后门（或陷门）是一种隐藏的方法，用于绕过正常的认证或安全控制，通常被恶意用于获得对系统的未经授权的访问。

56. What does the dispatcher imply?

56. 调度程序意味着什么？

Dispatcher is a component of the CPU scheduler that transfers control over CPU selection made by the scheduler itself. The dispatcher performs context switching, i.e., changing the CPU from one process to another selected process and ensuring the selected process starts execution.
调度程序是 CPU 调度器 的一个组件，它将调度器自身做出的 CPU 选择的控制权转移。调度程序执行上下文切换，即从一个进程切换到另一个选定的进程，并确保选定的进程开始执行。

57. What is the Locality of reference?

57. 引用局部性是什么？

Locality of reference refers to the tendency of a program to access a relatively small set of memory locations repeatedly over a short period. It is divided into two types:
局部性原理是指一个程序在短时间内反复访问相对较小的一组内存位置的倾向。它分为两种类型：

Type 类型	Description 描述
Temporal Locality 时间局部性	Recently accessed memory locations are likely to be accessed again soon. 最近访问过的内存位置可能很快再次被访问。
Spatial Locality 空间局部性	Memory locations near recently accessed locations are likely to be accessed soon. 靠近最近访问过的位置的内存位置可能很快被访问。

58. How do we calculate performance in virtual memory?

58. 如何计算虚拟内存中的性能？

Performance in virtual memory is calculated by evaluating the following factors:
虚拟内存中的性能通过评估以下因素来计算：

Factor 因素	Description 描述
Page Fault Rate 页面错误率	The frequency of page faults (lower is better) 页面错误的频率（越低越好）
Effective Access Time (EAT) 有效访问时间	Calculated as: EAT = (1 – Page Fault Rate) * Memory Access Time + Page Fault Rate * Page Fault Handling Time 计算公式为：EAT = (1 – 页面错误率) * 内存访问时间 + 页面错误率 * 页面错误处理时间
TLB Hit Rate TLB 命中率	The frequency of successful lookups in the Translation Lookaside Buffer (TLB) (higher is better) 在转换后备缓冲区（TLB）中成功查找的频率（越高越好）

59. What is reentrancy?

59. 什么是可重入性？

Reentrancy refers to the ability of a program or function to be safely interrupted and called again (“re-entered”) before its previous executions are complete. Reentrant code does not rely on shared data and uses local variables, allowing multiple instances to execute concurrently without causing conflicts.
可重入性是指程序或函数在之前的执行尚未完成之前能够被安全中断并再次调用（“重新进入”）的能力。可重入代码不依赖共享数据，而是使用局部变量，允许多个实例并发执行而不会导致冲突。

60. Write the top 10 examples of OS.

60. 写出操作系统的十个例子。

• Operating System
• Windows 10
• Windows 11
• macOS
• Linux (Ubuntu)
• Linux (Fedora)
• Linux (Debian)
• Android
• iOS
• FreeBSD
• Chrome OS

Advanced-level Operating System Interview Questions

高级操作系统面试问题

61. What are the different types of Kernel?

61. 内核的不同类型有哪些？

Kernel Type 内核类型	Description 描述
Monolithic Kernel 单体式内核	A single large kernel that handles all OS services in one address space. 一个大型单体式内核，处理一个地址空间中的所有操作系统服务。
Microkernel 微内核	A minimal kernel that runs basic services like communication and I/O in kernel space, with other services in user space. 一个最小的内核，在内核空间中运行基本服务，如通信和 I/O，其他服务在用户空间中。
Hybrid Kernel 混合式内核	Combines features of monolithic and microkernels to improve performance and modularity. 结合单体式和微内核的特点以提高性能和模块化。
Exokernel 外核	Provides minimal abstractions and allows applications to manage hardware resources directly. 提供最小的抽象，并允许应用程序直接管理硬件资源。
Nanokernel 纳内核	An extremely lightweight kernel that performs very few basic tasks, mainly used in embedded systems. 一个极其轻量级的内核，主要在嵌入式系统中执行少量的基本任务。

62. What do you mean by Semaphore in OS? Why is it used?

62. 在操作系统中，信号量是什么？为什么使用它？

A semaphore is a synchronisation variable that controls the number of processes that can access some common resource in a concurrent system. Basically, it’s an integer variable that could be increased or decreased due to the request of a process. Semaphores are majorly used to combat the problems of critical section and race conditions, as they ensure proper and secure access to shared resources.
信号量是一个同步变量，它控制并发系统中可以访问某些公共资源的进程数量。基本上，它是一个整数变量，可以根据进程的请求增加或减少。信号量主要用于解决临界区和竞争条件的问题，因为它们确保对共享资源的正确和安全访问。

63. What are the main functions of Kernel?

63. 内核的主要功能是什么？

Function 功能	Description 描述
Process Management 进程管理	Manages process creation, scheduling, and termination. 管理进程的创建、调度和终止。
Memory Management 内存管理	Controls memory allocation and deallocation. 控制内存分配和回收。
Device Management 设备管理	Manages communication between hardware devices and the system. 管理硬件设备与系统之间的通信。
File System Management 文件系统管理	Handles file creation, deletion, and access control. 处理文件的创建、删除和访问控制。
Security and Access Control 安全和访问控制	Enforces security policies and controls access to system resources. 强制执行安全策略并控制对系统资源的访问。
System Calls Management 系统调用管理	Provides an interface for user applications to interact with the hardware. 为用户应用程序提供与硬件交互的接口。

64. Write the difference between a microkernel and a monolithic kernel.

64. 写出微内核和单体式内核的区别。

Feature 特征	Microkernel 微内核	Monolithic Kernel 单体式内核
Structure 结构	Minimal core functions in kernel space other services in user space. 内核空间中的最小核心功能，其他服务在用户空间中。	All OS services run in kernel space. 所有操作系统服务都在内核空间中运行。
Size 大小	Smaller 较小	Larger 较大
Performance 性能	It can be slower due to user-space communication overhead. 由于用户空间通信开销，可能较慢。	Generally faster due to direct service handling in kernel space. 通常由于直接在内核空间中处理服务而更快。
Reliability 可靠性	More reliable and secure due to isolated services. 由于服务隔离，更可靠且安全。	Less reliable as a bug in one service can crash the entire system. 由于一个服务中的错误可能导致整个系统崩溃，因此可靠性较低。
Extensibility 可扩展性	Easier to extend and modify without affecting the entire system. 更容易扩展和修改，而不会影响整个系统。	Harder to modify and extend due to tightly coupled services. 由于服务紧密耦合，修改和扩展较为困难。

65. What does SMP mean (Symmetric Multiprocessing)?

65. SMP（对称多处理）是什么意思？

Symmetric multiprocessing (SMP) can be defined as an architecture in which one common memory exists with multiple processors operating under one operating system instance. For each processor it has equal access towards memory as well as I/O devices such that multitasking applications have parallel processing, resulting in better performance.
对称多处理（SMP）可以定义为一种架构，其中多个处理器在同一个操作系统实例下运行，共享一个通用内存。每个处理器对内存以及 I/O 设备都有平等的访问权，从而使得多任务应用程序能够进行并行处理，从而提高性能。

66. What is the time-sharing system?

66. 什么是分时系统？

Time-sharing allows several users or tasks to share the same system resources at once by switching between them quickly. Each user or task is given a short amount of time for their execution, which gives the impression of having many processes running at the same time thus increasing the general performance and responsiveness of the systems.
分时系统允许多个用户或任务同时共享相同的系统资源，通过快速在它们之间切换来实现。每个用户或任务都被分配了一小段时间用于执行，给人一种有许多进程同时运行的印象，从而提高了系统的整体性能和响应能力。

67. What are the benefits and disadvantages of a Batch Operating System?

67. 批处理操作系统的优点和缺点是什么？

Aspect 方面	Benefits 优点	Disadvantages 缺点
Efficiency 效率	Maximises resource utilisation by executing batches of jobs. 通过执行作业批次来最大化资源利用率。	Lack of interaction and flexibility for real-time tasks. 缺乏对实时任务的交互性和灵活性。
Automation 自动化	Reduces manual intervention and automates repetitive tasks. 减少人工干预并自动化重复任务。	Difficult to debug and handle errors during job execution. 在作业执行期间难以调试和处理错误。
Throughput 吞吐量	High throughput due to streamlined job processing. 由于作业处理流程化，吞吐量高。	Long turnaround time for individual jobs. 单个作业的周转时间长。
Cost 成本	Lower operational costs due to efficient resource usage. 由于资源使用效率高，运营成本低。	Inflexibility in handling diverse job requirements. 在处理多样化的作业需求时缺乏灵活性。

68. What is a bootstrap program in the OS?

68. 操作系统中的引导程序是什么？

A bootstrap program is the very first code that gets executed after a computer is started or reset. It has to initialise the hardware and do any other preparation necessary to make the environment run an operating system, which then also reads the OS kernel from disk into memory. A bootstrap program resides in the computer’s firmware (e.g., BIOS or UEFI)computer’s, which may be implemented in various ways depending on the computer’s design.
引导程序 是计算机启动或重置后执行的第一段代码。它必须初始化硬件并进行其他必要的准备，以便使环境能够运行操作系统，操作系统随后也会从磁盘读取 OS 内核到内存中。引导程序驻留在计算机的固件中（例如，BIOS 或 UEFI），具体实现方式取决于计算机的设计。

69. What are the different IPC mechanisms?

69. 不同的进程间通信机制有哪些？

IPC Mechanism IPC 机制	Description 描述
Pipes 管道	Allows communication between processes through a unidirectional data stream. 允许通过单向数据流在进程之间进行通信。
Message Queues 消息队列	Enables processes to exchange messages in a queue. 允许进程在队列中交换消息。
Shared Memory 共享内存	Allows multiple processes to access a common memory space. 允许多个进程访问一个公共内存空间。
Semaphores 信号量	Synchronises access to shared resources using signalling mechanisms. 使用信号机制同步对共享资源的访问。
Sockets 套接字	Facilitates communication between processes over a network. 促进进程通过网络进行通信。
Signals 信号	Uses asynchronous notifications to communicate events to processes. 使用异步通知向进程传达事件。

70. Which thing means deadlock in OS?

70. 在操作系统中，死锁是什么意思？

Deadlock occurs when some processes cannot go forward because every process waits for another process among this set holding a resource they need. Consequently, no single process can complete its execution, leading to the halting of the entire system. Deadlocks mainly involve four conditions: mutual exclusion, hold and wait, no preemption, and circular wait.
当一些进程无法继续前进，因为每个进程都在等待这个集合中的另一个进程持有的资源时，就会发生死锁。因此，没有任何单个进程可以完成其执行，导致整个系统停止运行。死锁主要涉及四个条件：互斥、保持和等待、不可剥夺和循环等待。

71. What do you mean by Belady’s Anomaly?

71. 什么是贝尔迪异常？

Belady’s Anomaly is a phenomenon in some page replacement algorithms where increasing the number of page frames increases the number of page faults. It occurs in algorithms like FIFO (First-In, First-Out), where more memory can paradoxically lead to worse performance due to suboptimal page replacement decisions.
贝尔迪异常是一些页面置换算法中的一个现象，其中增加页面帧的数量会导致页面错误的数量增加。它出现在像 FIFO（先进先出）这样的算法中，更多的内存可能会导致性能变差，因为页面置换决策不够理想。

72. What is spooling in the operating system?

72. 操作系统中的假脱机是什么？

Spooling (simultaneous peripheral operations online) is a technique where data is held temporarily in a buffer so that it can be used and executed by another device or program later on. This method is often employed for print management purposes whereby documents are spooled to disk or memory and lined up for printing, freeing up CPU cycles so that it can perform other tasks.
假脱机（在线同时外围设备操作）是一种技术，数据暂时保存在缓冲区中，以便稍后由另一个设备或程序使用和执行。这种方法通常用于打印管理，文档被假脱机到磁盘或内存中，并排队等待打印，从而释放 CPU 周期以执行其他任务。

73. Where is the Batch Operating System used in Real Life?

73. 批处理操作系统在现实生活中用于何处？

Batch Operating Systems are used in environments where large volumes of similar jobs are processed without user interaction. Real-life applications include:

• Payroll Systems: Processing employee salaries and benefits.
• Banking Systems: Handling end-of-day transactions and updates.
• Scientific Computation: Running extensive calculations and simulations.
• Data Processing: Large-scale data analysis and reporting.

批处理操作系统用于无需用户交互即可处理大量类似作业的环境中。现实生活的应用包括：

• 薪资系统：处理员工工资和福利。
• 银行系统：处理日终交易和更新。
• 科学计算：运行大量的计算和模拟。
• 数据处理：大规模数据分析和报告。

74. What are Monitors in the Context of Operating Systems?

74. 在操作系统上下文中，监视器是什么？

Monitors are high-level synchronisation constructs used to control access to shared resources in concurrent programming. They combine mutual exclusion (mutex) and condition variables to manage the safe execution of code blocks by allowing only one process or thread to execute within the monitor at a time.
监视器是用于控制并发编程中对共享资源的访问的高级同步构造。它们结合了互斥（mutex）和条件变量，通过只允许一个进程或线程在监视器内执行，来管理代码块的安全执行。

75. What is a zombie process?

75. 什么是僵尸进程？

A zombie process is a process that has completed execution but still has an entry in the process table. This occurs when the process’s parent has not read its exit status using the wait() system call. Zombie processes occupy a slot in the process table but do not consume system resources.
僵尸进程是一个已经完成执行但仍然在进程表中有条目的进程。当进程的父进程尚未使用 wait() 系统调用读取其退出状态时，就会出现这种情况。僵尸进程占据了进程表中的一个槽位，但不会消耗系统资源。

Conclusion

总结

Understanding concepts in an operating system will definitely raise the bar during technical interviews, providing you with a leading edge in the field of software development and IT. In this tutorial, you have learned process management, memory management, file systems, and security, all very important concepts that form the basis for undertaking operating system interview questions. This helps a lot in enhancing problem-solving skills and showcasing technical strengths to prospective hiring companies.
了解操作系统中的概念肯定会在技术面试中提升你的水平，为你在软件开发和 IT 领域提供竞争优势。在本教程中，你学习了进程管理、内存管理、文件系统和安全，这些是非常重要的概念，构成了回答操作系统面试问题的基础

The above questions are practice sets for you. Afterwards, apply these to real situations and continue to study for your interview. You may advance your career in technology and confidently handle challenging interview questions if you have a strong knowledge base of operating systems and have prepared thoroughly. To further strengthen your expertise, you can consider taking Certificate Program in Full Stack Development with Specialization for Web and Mobile by Hero Vired.
上述问题是你的练习题。之后，将这些应用到实际情况中，并继续为面试做准备。如果你对操作系统有扎实的知识基础并且准备充分，你就可以在技术领域推进你的职业生涯，并有信心应对具有挑战性的面试问题。

FAQs

常见问题

Which type of OS is Windows?

Windows 是什么类型的操作系统？

Windows is a multi-tasking operating system. It is actually a single-user operating system.
Windows 是一个多任务操作系统。实际上它是一个单用户操作系统。

What is the function of OS?

操作系统的功能是什么？

The operating system controls a computer’s hardware and software and serves as the interface between the user and the computer’s hardware. Main functions

操作系统控制计算机的硬件和软件，并作为用户与计算机硬件之间的接口。主要功能包括：

• File management: Handles files, such as creating, reading, writing, and deleting files
  文件管理：处理文件，例如创建、读取、写入和删除文件

• Memory management: Controls the computer’s memory, such as the amount of memory available and how to allocate it out
  内存管理：控制计算机的内存，例如可用内存量以及如何分配内存

• Process management: Controls how programs execute, including how to allocate CPU time and how to schedule tasks
  进程管理：控制程序的执行，包括如何分配 CPU 时间以及如何安排任务

• Input and output: Controls how the computer gets input from the user and how it provides output to the user
  输入和输出：控制计算机如何从用户那里获取输入以及如何向用户提供输出

• User interface: Gives a visible interface so the user can communicate with the computer.
  ​ 用户界面：提供一个可视化的界面，以便用户能够与计算机进行交互。

What is the full form of DOS?

DOS 的全称是什么？

DOS is a Disk Operating System and a computer program without which no personal computer can get along. It comes in two versions. The one distributed for IBM Personal Computers is referred to as PC-DOS. All other IBM-compatible personal computers utilize MS-DOS.
DOS 是磁盘操作系统，是一种计算机程序，个人计算机离不开它。它有两种版本。分发给 IBM 个人计算机的版本被称为 PC-DOS。所有其他兼容 IBM 的个人计算机都使用 MS-DOS。

What is CLI?

CLI 是什么？

CLI stands for the command-line interface, a computer’s text interface. It enables users to input commands into a terminal to execute tasks. How does CLI function? Users enter commands and parameters into a command prompt or terminal. The system carries out the commands. The default shell serves as a middleman between the operating system and the user.
CLI 代表命令行界面，是计算机的文本界面。它允许用户在终端中输入命令以执行任务。CLI 如何工作？用户在命令提示符或终端中输入命令和参数。系统执行这些命令。默认的外壳程序作为操作系统和用户之间的中介。

What is API in technology?

技术中的 API 是什么？

API is referred to as Application Programming Interface. It is a software bridge that facilitates communication between computer systems or programs.
API 是应用程序编程接口。它是一个软件桥梁，便于计算机系统或程序之间的通信。

Updated on February 22, 2025

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Operating System Structure in OS: Exploring the Different Types

操作系统结构：探索不同类型的结构

Updated on January 21, 2025

The operating system offers a channel of communication between the user and the hardware of computers. The operating system is topped with system software. The fundamental model required to implement operating systems is the operating system structure. Numerous structure types exist, each with unique characteristics that are elaborated upon.
操作系统为用户与计算机硬件之间提供了一个通信渠道。操作系统之上是系统软件。实现操作系统所需的基本模型就是操作系统结构。存在多种结构类型，每种结构都有其独特的特征，这些特征将在下文中详细阐述。

Operating System Structure – An Overview

操作系统结构概述

An operating system’s structure is complex, so in order to customize it to meet our unique requirements, we need a clear structure. Just as we would with a larger problem, divide an operating system into smaller, more manageable subproblems to facilitate solution. An operating system can be designed more simply in this manner. Every section is also a component of the operating system. The process of joining and incorporating different operating system components into the kernel is known as an operating system structure. Operating systems are implemented using a variety of structures, as will be covered in more detail below.
操作系统的结构是复杂的，因此为了满足我们独特的需求，我们需要一个清晰的结构。就像处理一个更大的问题一样，将操作系统分解为更小、更易于管理的子问题，以便找到解决方案。通过这种方式，可以更简单地设计操作系统。每个部分也是操作系统的一个组件。将不同的操作系统组件整合到内核中的过程被称为操作系统结构。操作系统使用多种结构来实现，这将在下文中更详细地介绍。

Types of Operating Systems Structures

操作系统结构的类型

Depending on the study, we have the following structures in the operating system:
根据研究的不同，操作系统有以下几种结构：

Simple

简单结构

It is the most basic and poorly defined operating system structure, and it is only suitable for tiny and constrained systems. Because the interfaces and functional levels are clearly divided in this structure, programs can access I/O routines, which may lead to unauthorized access to I/O routines. One example of such an operating system is MS-DOS. Application programs can access the basic I/O routines in MS-DOS. If one of the user programs on these kinds of operating systems malfunctions, the entire system crashes.
这是最基本且定义最不清晰的操作系统结构，仅适用于小型且受限的系统。由于这种结构中接口和功能层次划分明确，程序可以访问I/O例程，这可能导致对I/O例程的未授权访问。这种操作系统的例子之一是MS-DOS。应用程序可以访问MS-DOS中的基本I/O例程。如果这些操作系统中的一个用户程序出现故障，整个系统就会崩溃。

Advantages
优点

• Easy Development: Development is simple in systems with few interfaces and a simple operating system, especially when only a small number of functionalities are required.
  开发简单：在接口较少且操作系统简单的系统中，开发更为简单，尤其是当只需要少量功能时。

• Better Performance: Compared to other kinds of operating systems, such a system can perform better because it has fewer layers and interacts directly with hardware.
  性能更好：与其他类型的操作系统相比，这种系统由于层次较少且直接与硬件交互，因此性能更好。

Disadvantages
缺点

• Frequent System Failures: An inadequately thought out system lacks resilience. The operating system crashes when one program malfunctions. System failures are therefore rather common in basic operating systems.
  系统故障频繁：设计不够周全的系统缺乏弹性。当一个程序出现故障时，操作系统就会崩溃。因此，基础操作系统中的系统故障相当常见。

• Poor Maintainability: Because operating systems’ layers are all closely related, changes made to one can have a significant effect on others and eventually render code unmanageable.
  可维护性差：由于操作系统各层之间紧密相关，对其中一层的更改可能会对其他层产生重大影响，最终使代码难以管理。

Monolithic Structure

单体结构

An operating system (OS) on a computer is powered by its kernel. All other components of the system receive fundamental services from the kernel. It acts as the main point of contact between the hardware and the operating system. In systems that are monolithic, kernels have direct access to all operating system resources, including hardware components such as keyboards and mice.
计算机上的操作系统（OS）由其内核驱动。系统的其他所有组件都从内核获取基本服务。它作为硬件与操作系统之间的主要接触点。在单体系统中，内核可以直接访问所有操作系统资源，包括键盘和鼠标等硬件组件。

The monolithic operating system is also known as the monolithic kernel. By multiprogramming, batch processing and time-sharing optimize a processor’s usability. By operating on top of the operating system and managing every piece of hardware, the monolithic kernel performs the functions of a virtual machine. This antiquated operating system, which allows multiple users at different terminals to access the Operating System, was utilized in banks to carry out insignificant tasks like batch processing and time-sharing.
单体操作系统也被称为单体内核。通过多道程序、批处理和时间共享来优化处理器的可用性。单体内核在操作系统之上运行并管理每一块硬件，执行虚拟机的功能。这种过时的操作系统允许不同终端的多个用户访问操作系统，曾在银行中用于执行诸如批处理和时间共享等不重要的任务。

Advantages
优点

• Easy Development: As kernel is the only layer to develop with all major functionalities, it is easier to design and develop.
  开发简单：由于内核是唯一需要开发的层，且包含所有主要功能，因此设计和开发更为容易。

• Performance: As Kernel is responsible for memory management, other operations and has direct access to the hardware, it performs better.
  性能：由于内核负责内存管理和其他操作，并且直接访问硬件，因此性能更好。

Disadvantages
缺点

• Crash Prone: As Kernel is responsible for all functions, if one function fails the entire operating system fails.
  容易崩溃：由于内核负责所有功能，如果一个功能失败，整个操作系统就会失败。

• Difficult to enhance: It is very difficult to add a new service without impacting other services of a monolith operating system.
  难以增强：在不影响单体操作系统的其他服务的情况下，添加新服务非常困难。

Micro-Kernel Structure

微内核结构

The operating system is designed by the Micro-Kernel structure, which eliminates all of the kernel’s unnecessary parts. These optional kernel parts are implemented as user programs and systems. These systems are therefore referred to as micro-kernels.
操作系统由微内核结构设计，该结构消除了内核的所有不必要的部分。这些可选的内核部分作为用户程序和系统实现。因此，这些系统被称为微内核。

Every Micro-Kernel is created separately and kept apart from the others. As a result, the system is more trustworthy and secure. When a Micro-Kernel malfunctions, the rest of the operating system is unaffected and continues to function normally.
每个微内核都是单独创建并与其他内核分开的。因此，系统更加可靠和安全。当一个微内核出现故障时，操作系统的其余部分不受影响，继续正常运行。

Advantages
优点

• It makes the operating system portable to various platforms.

  可移植性强：使操作系统能够移植到各种平台。

• As microkernels are small so these can be tested effectively.

  易于测试：由于微内核较小，因此可以有效地进行测试。

Disadvantages
缺点

• Increased level of inter module communication degrades system performance.

  性能下降：模块间通信的增加会降低系统性能。

Hybrid-Kernel Structure

混合内核结构

The components of both monolithic and microkernel structures are combined in a hybrid kernel structure. A tiny microkernel at the center of the hybrid kernel handles crucial functions like inter-process communication (IPC), memory management, and process scheduling. Additional operating system services are implemented as user space modules.
混合内核结构结合了单体内核和微内核结构的组件。混合内核的中心是一个微小的微内核，负责处理进程间通信（IPC）、内存管理和进程调度等关键功能。其他操作系统服务作为用户空间模块实现。

This strategy seeks to combine the benefits of a microkernel’s stability and modularity with the performance advantages of a monolithic kernel.
这种策略旨在结合微内核的稳定性和模块化与单体内核的性能优势。

Advantages
优点

• It offers good performance as it implements the advantages of both structures in it.

  性能良好：因为它结合了两种结构的优点，因此性能良好。

• It supports a wide range of hardware and applications.

  支持广泛：支持广泛的硬件和应用程序。

• It provides better isolation and security by implementing a micro-kernel approach.

  隔离和安全：通过实现微内核方法，提供更好的隔离和安全性。

• It enhances overall system reliability by separating critical functions into micro-kernel for debugging and maintenance.

  增强可靠性：通过将关键功能分离到微内核中进行调试和维护，增强系统的整体可靠性。

Disadvantages
缺点

• It increases the overall complexity of a system by implementing both structure (monolithic and micro) and making the system difficult to understand.

  复杂性增加：通过实现两种结构（单体和微内核），增加了系统的整体复杂性，使系统难以理解。

• The layer of communication between the micro-kernel and other components increases time complexity and decreases performance compared to monolithic kernels.

  性能下降：微内核与其他组件之间的通信层增加了时间复杂性，与单体内核相比降低了性能。

Exo-Kernel Structure

外核结构

An operating system kernel known as an exokernel only offers the most fundamental functions, like memory management and communication. User-level processes handle the provision of all other services. Because of this, exokernel systems are very flexible and modular, but they are also difficult to implement.
外核是一种操作系统内核，仅提供最基本的功能，如内存管理和通信。用户级进程负责提供所有其他服务。因此，外核系统非常灵活且模块化，但它们也难以实现。

An alternative operating system architecture that differs greatly from conventional monolithic or microkernel architectures is the exokernel structure. An exokernel is a kernel that exposes hardware resources directly to applications and offers a minimal interface for those applications to manage.
外核结构是一种与传统单体或微内核架构大不相同的替代操作系统架构。外核是一种将硬件资源直接暴露给应用程序并为这些应用程序提供最小接口以进行管理的内核。

Advantages
优点

• Support for improved application control.

  支持改进的应用程序控制。

• Separates management from security.

  分离管理与安全。

• It improves the performance of the application.

  提高应用程序性能。

• A more efficient use of hardware resources is made possible by accurate resource allocation and revocation.

  高效利用硬件资源：通过精确的资源分配和撤销，实现硬件资源的更高效利用。

• It is simpler to test and create new operating systems.

  便于测试和创建新操作系统。

• Each user-space program is allowed to use a custom memory management system.

  自定义内存管理系统：每个用户空间程序都可以使用自定义的内存管理系统。

Disadvantages
缺点

• A decline in consistency.

  一致性下降。

• Exokernel interfaces have a complex architecture.

  接口复杂：外核接口具有复杂的架构。

Layered Structure

分层结构

The operating system is separated into levels or layers in this kind of structure. The user interface is on layer N, the top layer, and the hardware is on layer 0, or the bottom layer. The top-level layers of these layers utilize the functionalities of their lower-level layers in a hierarchical arrangement.
在这种结构中，操作系统被分为不同的层次或级别。用户界面位于第N层（最顶层），而硬件位于第0层（最底层）。这些层次的顶层利用其底层的功能，形成层次化的安排。

Each layer’s functionalities are separated in this method, and abstraction is also offered. Since layered structure is a hierarchical model, debugging is made simpler by checking the upper layer after all lower-level layers have been debugged. Thus, only the current layer needs to be checked; all other layers have already been examined.
通过这种方法，每一层的功能被分离，并且提供了抽象。由于分层结构是一种层次化模型，因此在调试所有底层之后再检查上层，使得调试变得更加简单。因此，只需要检查当前层，其他层已经检查过了。

Modular Structure

模块化结构

An operating system that has a modular structure is separated into a number of separate modules. Every module is in charge of a particular function, like device drivers, process scheduling, or memory management. Modules can dynamically load and unload as required.
具有模块化结构的操作系统被分为多个独立模块。每个模块负责特定的功能，如设备驱动程序、进程调度或内存管理。模块可以根据需要动态加载和卸载。

Virtual Machines

虚拟机

Multiple operating systems can run concurrently on a single physical machine thanks to a technology called virtual machines, or VMs. With its own operating system and set of apps, every virtual machine functions as a separate, isolated system.
多亏了虚拟机（VM）技术，多个操作系统可以在一台物理机上同时运行。每个虚拟机都有自己的操作系统和应用程序集，作为一个独立、隔离的系统运行。

Conclusion

结论

Operating systems can be built using various structures, each affecting how components interact within the kernel. These structures include Simple/Monolithic, Micro-Kernel, Hybrid-Kernel, Exo-Kernel, Layered, Modular, and Virtual Machines. The structure chosen influences the ease of use, modification, and overall efficiency. By breaking down the OS into manageable parts, developers can create more adaptable and robust systems. Understanding these structures helps in designing operating systems that meet specific needs while maintaining functionality and performance.
操作系统可以使用多种结构来构建，每种结构都影响内核中组件的交互方式。这些结构包括简单/单体、微内核、混合内核、外核、分层、模块化和虚拟机。所选择的结构影响易用性、可修改性和整体效率。通过将操作系统分解为可管理的部分，开发人员可以创建更具适应性和健壮性的系统。了解这些结构有助于设计满足特定需求同时保持功能和性能的操作系统。

FAQs

常见问题

There exist numerous variations of operating systems. A monolithic structure, or just one binary file occupying one memory location, is the typical configuration. layered structures that start at 0 with a hardware layer and go upward in nested layers, with each layer only communicating with the layer below it.
操作系统存在许多变体。单体结构，即一个二进制文件占据一个内存位置，是典型的配置。分层结构从0层的硬件层开始，向上形成嵌套层，每一层仅与其下层通信。

Modular Structure It is regarded as the OS’s ideal strategy. Creating a modular kernel is required. Other services are added to the kernel as dynamically loadable modules either during runtime or boot time. The kernel consists of only a few core components.
模块化结构被认为是操作系统的理想策略。需要创建一个模块化内核。其他服务作为动态可加载模块在运行时或启动时添加到内核中。内核仅由几个核心组件组成。

The small number of interfaces and layers makes it simple to develop. provides good performance since there are fewer layers separating the applications and hardware.
接口和层次较少使得开发变得简单。由于应用程序和硬件之间的层次较少，因此性能较好。

Updated on January 21, 2025

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不同类型内核比较

内核类型	定义	应用场景	优点	缺点
微内核（Microkernel）	仅包含操作系统最基本的功能，如进程间通信（IPC）、内存管理和基本的调度功能等。大部分操作系统服务作为用户空间的进程来实现	适用于对可靠性和可扩展性要求较高的系统，如嵌入式系统、实时操作系统等	高可扩展性，添加、删除或修改服务相对容易；高可靠性，某个服务故障不影响整个内核稳定性；可移植性好，代码量小，移植简单	用户空间和内核空间之间频繁切换带来性能开销
宏内核（Monolithic Kernel）	将所有的操作系统功能，包括进程管理、内存管理、设备驱动程序、文件系统等都集成在内核中	适用于对性能要求较高且硬件环境相对固定的系统，如桌面操作系统（如 Linux、Windows）	高性能，避免用户空间和内核空间频繁切换；设计和实现相对简单，开发和维护成本较低	可扩展性差，修改和扩展功能需重新编译整个内核；可靠性低，一个模块故障可能导致系统崩溃
混合内核（Hybrid Kernel）	结合了微内核和宏内核的特点，将一些关键功能（如进程管理、内存管理）放在内核空间，部分相对次要功能（如部分设备驱动程序）放在用户空间	适用于对性能和可扩展性都有一定要求的系统，如一些服务器操作系统	性能和可扩展性的平衡，既保留宏内核高性能，又具备一定可扩展性	设计复杂，需要在性能和可扩展性之间进行权衡，设计和实现难度较大
外核（Exokernel）	将硬件资源的管理和保护交给内核，资源的使用和抽象交给用户空间的应用程序。内核只提供对硬件资源的基本访问接口，应用程序自行管理和使用资源	适用于对性能和资源利用率要求极高的系统，如高性能计算、云计算等	高度定制化，应用程序可根据需求管理资源实现更高性能和效率；资源利用率高，避免内核过度抽象和资源浪费	开发难度大，应用程序需自己处理资源管理和保护问题；兼容性差，不同应用程序资源管理方式可能不同
纳米内核（Nanokernel）	一种比微内核更精简的内核设计，只包含最基本的功能，如线程调度和进程间通信，常用于嵌入式系统和实时系统	适用于对内存占用和实时性要求极高的嵌入式系统，如传感器节点、智能卡等	极小的内存占用，可在内存非常有限的设备上运行；高实时性，内核功能简单，响应速度快	功能有限，只提供最基本功能，需在用户空间实现更多功能，增加开发复杂度

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via:

• Top 70+ Operating System Interview Questions and Answers
  https://herovired.com/learning-hub/blogs/os-interview-questions/

• Operating System Structure in OS: Different Types Explained
  https://herovired.com/learning-hub/topics/operating-system-structure/