Lecture Operating system concepts (9/ed) - Chapter 1: Introduction

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In this chapter, the following content will be discussed: What operating systems do, computer-system organization, computer-system architecture, operating-system structure, operating-system operations, process management, memory management, storage management, protection and security, kernel data structures, computing environments, open-source operating systems

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Nội dung Text: Lecture Operating system concepts (9/ed) - Chapter 1: Introduction

Chapter 1: Introduction Operating System Concepts – 9th Edit9on Silberschatz, Galvin and Gagne ©2013
Chapter 1: Introduction What Operating Systems Do Computer-System Organization Computer-System Architecture Operating-System Structure Operating-System Operations Process Management Memory Management Storage Management Protection and Security Kernel Data Structures Computing Environments Open-Source Operating Systems Operating System Concepts – 9th Edition 1.2 Silberschatz, Galvin and Gagne ©2013
Objectives To describe the basic organization of computer systems To provide a grand tour of the major components of operating systems To give an overview of the many types of computing environments To explore several open-source operating systems Operating System Concepts – 9th Edition 1.3 Silberschatz, Galvin and Gagne ©2013
What is an Operating System? A program that acts as an intermediary between a user of a computer and the computer hardware: Là 1 ch/trình hoạt động như 1 ng tr/gian giữa máy tính và phần cứng máy tính Operating system goals: mục đích của HĐH Execute user programs and make solving user problems easier: thực thi ch/trình và giúp g/quyết vấn đề của ng/dùng dễ dàng hơn Make the computer system convenient to use: giúp hệt thống máy tính thuận tiện hơ để sử dụng Use the computer hardware in an efficient manner: sử dụng ph/cứng trong ph/pháp hiệu quả Operating System Concepts – 9th Edition 1.4 Silberschatz, Galvin and Gagne ©2013
Computer System Structure Computer system can be divided into four components: hệ thống m/tính chia làm 4 th/phần Hardware – provides basic computing resources  CPU, memory, I/O devices Operating system  Controls and coordinates use of hardware among various applications and users: điều khiển và xác định việc sử dụng ph/cứng giữa nh~ ứng dụng và ng dùng khác nhau Application programs – define the ways in which the system resources are used to solve the computing problems of the users: đ/nghĩa cách t/nguyên h/thống đc sử dụng để g/quyết v/đề tính toán của ng/dùng  Word processors, compilers, web browsers, database systems, video games Users  People, machines, other computers Operating System Concepts – 9th Edition 1.5 Silberschatz, Galvin and Gagne ©2013
Four Components of a Computer System Operating System Concepts – 9th Edition 1.6 Silberschatz, Galvin and Gagne ©2013
What Operating Systems Do Depends on the point of view: p/thuộc vào điểm nhìn Users want convenience, ease of use and good performance: ng/dùng muốn th/tiện, dễ dùng và hiệu suất tốt Don’t care about resource utilization But shared computer such as mainframe or minicomputer must keep all users happy: nhưng việc chia sẻ máy tính phải giữ cho tất cả ng/dùng vui vẻ Users of dedicate systems such as workstations have dedicated resources but frequently use shared resources from servers: ng/dùng chia sẻ hệ thống như là nh~ workstation chia sẻ tài nguyên nhưng thường xuyên sử dụng tài nguyên từ server Handheld computers are resource poor, optimized for usability and battery life: máy tính cầm tay thì có tài nguyên nghèo nàn, tối ưu hóa cho việc sử dụng và tuổithọ pin Some computers have little or no user interface, such as embedded computers in devices and automobiles: 1 vài mát tính có 1 ít hoặc ko có g/diện ng/dùng, như là gắn máy tính vào những th/bị Operating System và –xe Concepts th hơi 9 Edition 1.7 Silberschatz, Galvin and Gagne ©2013
Operating System Definition OS is a resource allocator: cấp phát tài nguyên Manages all resources Decides between conflicting requests for efficient and fair resource use: q/định giữa 2 y/cầu cho việc sử dụng tài nguyên h/quả và thuận tiện OS is a control program Controls execution of programs to prevent errors and improper use of the computer: đ/khiển sự thực thi của ch/trình để ngăn cản nh~ lỗi và sử dụng ko đúng của m/tính Operating System Concepts – 9th Edition 1.8 Silberschatz, Galvin and Gagne ©2013
Operating System Definition (Cont.) No universally accepted definition “Everything a vendor ships when you order an operating system” is a good approximation(ước chừng): But varies wildly “The one program running at all times on the computer” is the kernel: 1 ch/trình chạy suốt th/gian trên m/tính là kernel Everything else is either a system program (ships(vận chuyển): with the operating system) , or an application program. Operating System Concepts – 9th Edition 1.9 Silberschatz, Galvin and Gagne ©2013
Computer Startup bootstrap program is loaded at power-up or reboot: ch/trình mồi đc load khi khởi động hoặc khởi động lại Typically stored in ROM or EPROM, generally known as firmware: lưu trữ điển hình trong ROM or EPROM, thường đc biết như là firmware Initializes all aspects of system: ch/bị tất cả khía cạnh của h/thống Loads operating system kernel and starts execution: load nhân của HĐH và bắt đầu thực thi Operating System Concepts – 9th Edition 1.10 Silberschatz, Galvin and Gagne ©2013
Computer System Organization: Computer-system operation(hoạt động) One or more CPUs, device controllers connect through common bus providing access to shared memory: 1 or nhiều cpu, nh~ điều khiển thiết bị kết nối thường thông qua bus cung ấp truy xuất đến bộ nhớ dùng chung Concurrent execution of CPUs and devices competing for memory cycles: sự thực thi đồng thời của cpu và nh~ th/bị cạnh tranh cho vòng đời bộ nhớ Operating System Concepts – 9th Edition 1.11 Silberschatz, Galvin and Gagne ©2013
Computer-System Operation I/O devices and the CPU can execute concurrently(đồng thời) Each device controller is in charge(phí) of a particular(đặc biệt) device type Each device controller has a local buffer: mỗi đ/khiển th/bị có 1 bộ đệm cục bộ CPU moves data from/to main memory to/from local buffers: cpu di chuyển dữ liệu từ/tới bộ nhớ chính từ/tới bộ đệm chục bộ I/O is from the device to local buffer of controller: nhập/xuất từ th/bị đến bộ đêm cục bộ của controller Device controller informs(thông báo) CPU that it has finished its operation by causing an interrupt(ngắt kết nối) Operating System Concepts – 9th Edition 1.12 Silberschatz, Galvin and Gagne ©2013
Common Functions of Interrupts Interrupt transfers control to the interrupt service routine(thường trình) generally, through the interrupt vector, which contains the addresses of all the service routines Interrupt architecture must save the address of the interrupted instruction(lệnh) A trap(bẫy lỗi) or exception(ngoại lệ) is a software- generated(tạo ra) interrupt caused either by an error or a user request An operating system is interrupt driven Operating System Concepts – 9th Edition 1.13 Silberschatz, Galvin and Gagne ©2013
Interrupt Handling The operating system preserves(duy trì) the state of the CPU by storing registers and the program counter Determines which type of interrupt has occurred: Polling: kiểm soát Vectored(đ/khiển) interrupt system Separate segments(phân đoạn) of code determine what action should be taken for each type of interrupt Operating System Concepts – 9th Edition 1.14 Silberschatz, Galvin and Gagne ©2013
Interrupt Timeline Operating System Concepts – 9th Edition 1.15 Silberschatz, Galvin and Gagne ©2013
I/O Structure After I/O starts, control returns to user program only upon(trong lúc) I/O completion Wait instruction idles(để ko) the CPU until the next interrupt Wait loop (contention(n/dung) for memory access) At most one I/O request is outstanding(chưa g/quyết) at a time, no simultaneous(đồng thời) I/O processing After I/O starts, control returns to user program without waiting for I/O completion System call – request to the OS to allow user to wait for I/O completion Device-status table contains entry for each I/O device indicating(cho biết) its type, address, and state OS indexes into I/O device table to determine device status and to modify(sửa đổi) table entry to include interrupt Operating System Concepts – 9th Edition 1.16 Silberschatz, Galvin and Gagne ©2013
Storage Definitions and Notation Review The basic unit of computer storage is the bit. A bit can contain one of two values, 0 and 1. All other storage in a computer is based on collections of bits. Given enough bits, it is amazing how many things a computer can represent: numbers, letters, images, movies, sounds, documents, and programs, to name a few. A byte is 8 bits, and on most computers it is the smallest convenient chunk(g/quy ết vi ệc khó khăn) of storage. For example, most computers don’t have an instruction to move a bit but do have one to move a byte. A less common term is word, which is a given computer architecture’s native(t ự nhiên) unit of data. A word is made up of one or more bytes. For example, a computer that has 64bit registers and 64bit memory addressing typically(điển hình) has 64bit (8byte) words. A computer executes many operations in its native word size rather than a byte at a time. Computer storage, along with most computer throughput, is generally measured(đều đặn) and manipulated in bytes and collections of bytes. A kilobyte, or KB, is 1,024 bytes a megabyte, or MB, is 1,0242 bytes a gigabyte, or GB, is 1,0243 bytes a terabyte, or TB, is 1,0244 bytes a petabyte, or PB, is 1,0245 bytes Computer manufacturers often round off these numbers and say that a megabyte is 1 million bytes and a gigabyte is 1 billion bytes. Networking measurements are an exception to this general rule; they are given in bits (because networks move data a bit at a time). Operating System Concepts – 9th Edition 1.17 Silberschatz, Galvin and Gagne ©2013
Storage Structure Main memory – only large storage media that the CPU can access directly Random access Typically(điển hình) volatile(khả biến) Secondary storage – extension of main memory that provides large nonvolatile storage capacity Hard disks – rigid(cứng) metal(kim loại) or glass platters(đĩa) covered with magnetic(từ tính) recording material(vật liệu) Disk surface is logically divided into tracks, which are subdivided into sectors The disk controller determines the logical interaction between the device and the computer Solid-state disks – faster than hard disks, nonvolatile Various technologies Becoming more popular Operating System Concepts – 9th Edition 1.18 Silberschatz, Galvin and Gagne ©2013
Storage Hierarchy Storage systems organized in hierarchy Speed Cost Volatility Caching – copying information into faster storage system; main memory can be viewed as a cache for secondary storage Device Driver for each device controller to manage I/O Provides uniform(đều) interface between controller and kernel Operating System Concepts – 9th Edition 1.19 Silberschatz, Galvin and Gagne ©2013
Storage-Device Hierarchy Operating System Concepts – 9th Edition 1.20 Silberschatz, Galvin and Gagne ©2013