CS 423 Operating Systems Design Lecture 1 Introduction

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CS 423 Operating Systems Design Lecture 1 -
Introduction

• Klara Nahrstedt/Sam King
• Fall 2007

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Overview

• Course information (personnel, policy, schedule,
  misc.)
• What is OS? What does it do?
• History of OS
• Summary

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Instructors

• Klara Nahrstedt
• PhD University of Pennsylvania
• Research
• Multimedia distributed systems (overlay
  multicast, peer-to-peer systems, service
  composition),
• Multimedia operating systems (soft-real-time
  scheduling, caching),
• Multimedia networking (routing, QoS management,
  pricing, security),
• Multimedia applications (multi-camera
  tele-immersive systems)
• Sam King
• PhD University of Michigan
• Research
• Operating Systems Design
• Security in Operating Systems
• Virtual Machines in Operating Systems

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Overview

• Office Assistants
• Anda Ohlsson (ohlsson_at_cs.uiuc.edu) for Klara
  Nahrstedt
• Trisha Benson for Sam King
• Teaching Assistants
• Kenton McHenry
• Shuo Tang (Internet TA)
• Class Website http//www.cs.uiuc.edu/class/fa07/
  cs423/
• Newsgroup uiuc.class.cs423 and
  uiuc.class.cs423.announce
• Two newsgroups one for discussion on machine
  problems, one for announcements

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Required Readings for cs423

• Required Textbook
• Modern Operating Systems, Andrew Tanenbaum,
  Prentice Hall, second edition, 2001
• Understanding the LINUX Kernel, Bovet and Cesati,
  OReilly, third edition, 2006 (kernel 2.6)

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Course Prerequisites

• CS 241 MUST
• There will be a test similar to exams of cs241
  (take-home exam)
• If you can finish more than 80 of the exam, you
  should be fine in the class
• If you cannot finish the exam with 70 and lower,
  then it means that you should consider sitting in
  cs241 or taking it first
• Take-home exam will be given on 8/31
• Solutions to take-home exam will be posted on 9/07

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Facilities and Office Hours

• Laboratory Facilities
• CSIL-linux clusters, 216 SC,
• Office hours available in web page
• KN Tue/Thu, 9-10am, Office 3104 SC
• SK Mon/Wed 11-noon, Office 4306 SC
• KM Wed/Fri, 1-2pm, Office 1514 BI (Beckman
  Institute)
• ST - no office hours (only via email )
  Intensive Email handling on Tuesdays and
  Thursdays

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About this course

• Principles
• System concepts
• OS design
• Some theory
• Rationale
• Practice

• Goals
• Understand OS decisions
• Basis for future learning
• Get hands dirty

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Expect (Some) Pain

• Fast pace
• Hard material
• 4 MPs (programming)
• 2 Homework
• 1 Midterm and 1 Final (Comprehensive) Exam
• But.
• Students survived past cs423!

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Grading

• Final exam 35
• Mid-exam 20
• 2 Homework 10
• 4 MPs 35 (depending on the difficulty each MP
  will have different weight
• 1st MP 7
• 2nd MP 8
• 3rd MP 10
• 4th MP 10

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Grading policy

• Gradebook system http//compass.uiuc.edu
• Late policy for MPs and Homework Assignments
• No Late Policy, but there will be 3 Bonus Days
• It is your responsibility!
• Check announcements in lectures, newsgroups, or
  web pages
• MPs will be done in Groups of 2-3 students
• MPs done on vmware server

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Group Setup

• Setup Groups between 8/22 and 8/24
• Email to the TA Shuo (stang6_at_uiuc.edu ) your
  group formation
• David Andersen (system admin) will setup accounts
  on the vmware server.
• Between 8/27 and 29 the TA (Shuo) will inform
  each group their login and password to start to
  work on the vmware server.
• The instructions about working on the vmware
  server will be also posted on web as well as
  mailed to each group.

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Re-grading policy

• Students have 1 week (after the grade for a
  Homework/MP/exam is released into gradebook) to
  request for re-grading
• Re-grading requests need to be in writing to the
  TAs
• After the re-grading period, no re-grading
  request will be granted for this
  Homework/MP/exam.

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Cheating Policy

• Academic integrity
• Your homework and exams must be your own - we
  have a zero tolerance policy towards cheating of
  any kind and any student who cheats will get a
  failing grade in the course.
• Both the cheater and the student who aided the
  cheater will be held responsible for the cheating
• Machine problems will be graded per group, i.e.,
  each member gets the same number of points.

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Lecture Format

• Help you understand important and hard OS
  concepts
• Lectures do not cover everything
• Not all questions in homework or exams are from
  lectures
• Students responsibility
• Attend lectures
• Read textbooks
• Homework, MP, Exam
• Periodically check web page
• Read/utilize newsgroup

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MPs (Deadlines)

• QA Session before each MP due date
• MP releases and QA Session dates will be
  announced
• on the course web page/newsgroup

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Homework Exams

• Announcement in web page
• No makeup homework
• No makeup exams unless with documented
  medical emergency

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¼ Unit Project graduate students

• Final grade is decided upon ¾ unit performance
• ¼ unit project pass or fail
• Individual or group of two
• Choices
• Implementation project
• Animation project
• Survey
• Proposal due 9/14, Friday, 5pm, by email to
  klara_at_cs.uiuc.edu and kingst_at_cs.uiuc.edu
• Details in web page

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What Is an OS?

• Code that
• Sits between programs hardware
• Sits between different programs
• Sits betweens different users
• But what does it do?
• to provide an orderly and controlled allocation
  of the processors, memories and I/O devices among
  the various programs competing for them
• Real Life Example
• Government

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What Is an OS?

• Resources
• Allocation
• Protection
• Reclamation
• Virtualization

• Services
• Abstraction
• Simplification
• Convenience
• Standardization

Makes computers simpler
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What Is an OS?
Government
Limited budget,Land,Oil,Gas,

• Resources
• Allocation
• Protection
• Reclamation
• Virtualization

• Finite resources
• Competing demands
• Examples
• CPU
• Memory
• Disk
• Network

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What Is an OS?
Government
Law and order

• You cant hurt me
• I cant hurt you
• Implies some degree of safety security

• Resources
• Allocation
• Protection
• Reclamation
• Virtualization

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What Is an OS?
Government

• The OS gives
• The OS takes away
• Voluntary at run time
• Implied at termination
• Involuntary
• Cooperative

Income Tax

• Resources
• Allocation
• Protection
• Reclamation
• Virtualization

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What Is an OS?
Government
Social security

• Resources
• Allocation
• Protection
• Reclamation
• Virtualization

• illusion of infinite, private resources
• Memory versus disk
• Timeshared CPU
• More extreme cases possible ( exist)

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History of Operating Systems (1)

• First generation 1945 1955
• vacuum tubes, plug boards (no OS)
• Second generation 1955 1965
• transistors, batch systems
• Third generation 1965 1980
• ICs and multiprogramming
• Fourth generation 1980 present
• personal computers, hand-held devices, sensors

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History of Operating System (1945-55)

• Early batch system
• bring cards to 1401
• read cards to tape
• put tape on 7094 which does computing
• put tape on 1401 which prints output

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History of Operating Systems (1955-65)

• Structure of a typical JCL job 2nd generation
• Single user
• Programmer/User as the operator
• Secure, but inefficient use of expensive
  resources
• Low CPU utilization-slow mechanical I/O devices

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History of Operating Systems (1965-80)

• Multiprogramming system
• Three jobs in memory 3rd generation
• Spooling - use disk as a very large buffer for
  input/output devices
• Polling/Interrupts, Timesharing

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The Operating System Zoo (1980-present)

• Mainframe operating systems
• Server operating systems
• Multiprocessor operating systems
• Personal computer operating systems
• Real-time operating systems
• Embedded operating systems
• Smart card operating systems

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Historical Comparison
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Summary

• Course overview
• Policy and requirement
• What is OS?
• OS history
• Next lecture system overview (chapter 1.4-1.6
  review of cs241 concepts)

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After this lecture

• Reading assignment chapter 1
• Browse the web site
• Subscribe to newsgroup
• Login to csil machines
• Setup Groups 8/22-8/26(email to Shu about group
  formation)
• Think about what are the criteria to evaluate an
  OS?