13_IO system

13_IO system - Chapter 13: I/O Systems Chapter Chapter 13:...

Info iconThis preview shows pages 1–9. Sign up to view the full content.

View Full Document Right Arrow Icon
Chapter 13: I/O Systems Chapter 13: I/O Systems
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
13.2 Modified by Bo Li ©2009 Operating System Concepts Chapter 13: I/O Systems Chapter 13: I/O Systems I/O Hardware Application I/O Interface Kernel I/O Subsystem Transforming I/O Requests to Hardware Operations Streams Performance
Background image of page 2
13.3 Modified by Bo Li ©2009 Operating System Concepts Objectives Objectives Explore the structure of an operating system’s I/O subsystem Discuss the principles of I/O hardware and its complexity Provide details of the performance aspects of I/O hardware and software
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
13.4 Modified by Bo Li ©2009 Operating System Concepts Memory Hierarchy in Computer System Memory Hierarchy in Computer System Take advantage of the principle of locality to: Present as much memory as in the cheapest technology Provide access at speed offered by the fastest technology On-Chip Cache Registers Control Datapath Secondary Storage (Disk) Processor Main Memory (DRAM) Second Level Cache (SRAM) 1 10,000,000 (10s ms) Speed (ns): 10-100 100 100s Gs Size (bytes): Ks-Ms Ms Tertiary Storage (Tape) 10,000,000,000 (10s sec) Ts
Background image of page 4
13.5 Modified by Bo Li ©2009 Operating System Concepts The Requirements of I/O The Requirements of I/O What we have learned: CPU, memory What about I/O? Without I/O, computers are useless, but… thousands of devices, each slightly different How can we standardize the interfaces to these devices ? Devices unreliable: media failures and transmission errors How can we make them reliable??? Devices unpredictable and/or slow How can we manage them if we don’t know what they will do or how they will perform? Some operational parameters: Byte/Block Some devices provide single byte at a time ( e.g. keyboard) Others provide whole blocks ( e.g. disks, networks, etc) Sequential/Random Some devices must be accessed sequentially ( e.g. tape) Others can be accessed randomly ( e.g. disk, cd, etc.) Polling/Interrupts Some devices require continual monitoring Others generate interrupts when they need service
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
13.6 Modified by Bo Li ©2009 Operating System Concepts Modern I/O Systems Modern I/O Systems
Background image of page 6
13.7 Modified by Bo Li ©2009 Operating System Concepts Standard Interfaces to Devices Standard Interfaces to Devices Block Devices: e.g. disk drives, tape drives, CDRom Access blocks of data Commands include open(), read(), write(), seek() Raw I/O or file-system access Memory-mapped file access possible Character Devices: e.g. keyboards, mice, serial ports, some USB devices Single characters at a time Commands include get(), put() Libraries layered on top allow line editing Network Devices: e.g. Ethernet, Wireless, Bluetooth Different from block/character to have own interface Unix and Windows include socket interface Separates network protocol from network operation Includes select() functionality Usage: pipes, FIFOs, streams, queues, mailboxes
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
13.8
Background image of page 8
Image of page 9
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 09/24/2010 for the course COMP 252 taught by Professor Wong during the Fall '09 term at HKUST.

Page1 / 38

13_IO system - Chapter 13: I/O Systems Chapter Chapter 13:...

This preview shows document pages 1 - 9. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online