CS 423 - Fall 2011

CS 423 – Operating Systems Design

Lecture 1 - Introduction

Klara Nahrstedt

Fall 2011

CS 423 - Fall 2011

Overview

Course information (personnel, policy, schedule, misc.)

What is OS? What does it do? History of OS Summary

CS 423 - Fall 2011

Instructor Klara Nahrstedt

PhD University of Pennsylvania in 1995 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)

Mobile Peer-to-Peer Systems – Content Distribution Resource Management in Wireless 802.11 Networks Power-aware OS in mobile devices Mobility Patterns in Mobile Learning Communities

CS 423 - Fall 2011

Overview Office Assistants:

Lynette Lubben (llubben@illinois.edu) for Klara Nahrstedt

Teaching Assistants: Raoul Rivas (trivas@illinois.edu) Keun Soo Yim (yim6@illinois.edu) (Online TA)

Class Website http://www.cs.illinois.edu/class/fa11/cs423/

Newsgroup: uiuc.class.cs423 and uiuc.class.cs423.announce Two newsgroups – one for discussion on machine problems, one

for announcements

CS 423 - Fall 2011

Required Readings for cs423 Required Textbook:

Modern Operating Systems, Andrew S. Tanenbaum, Prentice Hall, third edition, 2008

Recommended Textbooks: Linux Kernel Development, Robert Love, Safari Online Book,

2010, 3rd edition. Linux Device Drivers, Corbet, Rubini, Kroah-Hartman,

O’REILLY, 2005, 3rd edition. Pro Android 2, Hashimi, Komatineni, MacLean, Apress, 2010. But mostly online resources

CS 423 - Fall 2011

Course Prerequisites CS 241 – MUST (or similar course)

There will be a test similar to exams of cs241 (take-home exam – not graded – it is for your own evaluation)

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 posted on 8/26 Solutions to take-home exam will be posted on 9/1

CS 423 - Fall 2011

Facilities and Office Hours Laboratory Facilities

CSIL- linux and windows machines, 216 SC, Starting October 14, we will start leasing Android

phones for MP3 and MP4 assignments. Nexus-S and Droid phones

Office hours: available in web page For online students:

we will have collaborative tool ‘elluminate’ - will be available for online TA office hours

Otherwise use with Instructor/TAs to communicate Skype, Email, Chat – text messaging

Online Students

Recording links sent by email to online students

There will be link from class website to the recording server for all students (protected by password after two weeks)

CS 423 - Fall 2011

CS 423 - Fall 2011

About this course…Principles

System concepts OS design Algorithms Policies Rationale Practice

Goals

Understand OS decisions

Basis for future learning

Get hands dirty Linux and/or Android

CS 423 - Fall 2011

Expect (Some) PainFast pace

Hard material

4 MPs (programming)

2 Homework

1 Midterm and 1 Final (Comprehensive) Exam

But….

Students survived past cs423!

Source: http://en.wikipedia.org/wiki/Ben_Bernanke

CS 423 - Fall 2011

Grading Final exam: 35% Mid-exam: 20% 2 Homework: 10% 4 MPs: 35%

1st MP – not graded but absolutely essential to do – practice to work with the Linux

2nd MP – 11% - major Linux scheduling problem 3rd MP – 11% - resource management problem

(power, file system, memory …) Two options: Linux or Android

4th MP – 13% - distributed load management Two options: Linux or Android

CS 423 - Fall 2011

Grading policy Gradebook system: http://compass.uiuc.edu Late policy for MPs and Homework

AssignmentsNo Late Policy, but there will be 3 Bonus Days

(can’t take all three bonus days for one MP!) 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

CS 423 - Fall 2011

Group Setup Setup Groups between 8/22 and 8/24

By evening of 8/24, you should setup groups on compass.illinois.edu (under cs423 Fall 2011 class) by filling out the form under “MP Sign up”

If there are any issues, email to the TA (Raoul Rivas - trivas@illinois.edu)

Specify name of the group members and netid of group members David Andersen (system admin) will setup accounts on

the vmware server. Between 8/27 and 29 the TA 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 class web and compass.

CS 423 - Fall 2011

Re-grading policy Students have 1 week (after the grade for a

Homework/MP/exam is released into compass 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.

CS 423 - Fall 2011

Cheating Policy Academic integrity https://wiki.engr.illinois.edu/display/undergradProg/

Honor+CodeYour homework and exams must be your own - we have a zero tolerance policy towards cheating of any kind.

FIRST OFFENSE – 0 points on any homework, exam, MP, SECOND OFFENSE - F - 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.

CS 423 - Fall 2011

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 (read textbook)

Students responsibilityAttend lecturesRead textbooks Homework, MP, Exam, InterviewsPeriodically check web pageRead/utilize newsgroup

CS 423 - Fall 2011

MPs (Deadlines)MP1, 9/9/2011 (recommended – not graded)

Proc File, Synchronization, warm up to prepare working within Linux kernel

MP2, Friday, 9/30 - deadline

Monday 10/3 - interviews

Kernel Process Management/ Scheduling

MP3, Friday, 11/4 – deadline

Monday 11/7 - interviews

Resource Management (Android or Linux)

MP4, Friday, 12/2 – deadline

Monday 12/5 – interviews

Power/Time-sensitive Distributed Load balancing - more of an open ended assignment - Competition for students who pick Android for the final MP4

CS 423 - Fall 2011

Homework & Exams• Announcement in web page/newsgroup/compass• No makeup homework• No makeup exams unless with documented medical emergency

10/3-10/10, 5pm HW1

10/12, Monday,

10-10:50amMidterm Exam (In-class)

11/28-12/7, 5pm HW2

12/15, Thursday, 8-11am

Room: TBD

Final Exam (Comprehensive)

CS 423 - Fall 2011

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: 9/16, Friday, 5pm

Write: ½ - 1 page of proposal in ascii or pdf format Specify: (a) scope of the problem, (b) problem description, (c)

deliverables, (d) timelines. Email to klara@illinois.edu

Details in web page

CS 423 - Fall 2011

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

CS 423 - Fall 2011

What Is an OS?Resources Allocation Protection Reclamation Virtualization

Services Abstraction Simplification Convenience Standardization

Makes computers simpler

CS 423 - Fall 2011

What Is an OS?

Resources Allocation Protection Reclamation Virtualization

Finite resources

Competing demands

Examples: CPU Memory Disk Network

CS 423 - Fall 2011

What Is an OS?

Resources Allocation Protection Reclamation Virtualization

You can’t hurt me

I can’t hurt you

Implies some degree of safety & security

CS 423 - Fall 2011

What Is an OS?

Resources Allocation Protection Reclamation Virtualization

The OS gives

The OS takes away

Voluntary at run time

Implied at termination

Involuntary

Cooperative

CS 423 - Fall 2011

What Is an OS?

Resources Allocation Protection Reclamation Virtualization

illusion of infinite, private resources

Memory versus disk

Timeshared CPU

CS 423 - Fall 2011

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

CS 423 - Fall 2011

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

CS 423 - Fall 2011

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

CS 423 - Fall 2011

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

CS 423 - Fall 2011

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

CS 423 - Fall 2011

Summary

Course overview Policy and requirement What is OS? OS history

Next lecture: OS architectures/system overview

CS 423 - Fall 2011

After this lecture… Reading assignment: chapter 1.1-1.4 Browse the web site Subscribe to newsgroup Login to csil machines, compass, … Setup Groups: 8/22-8/26(fill out form on

compass and submit the form) Think about what are the criteria to

evaluate an OS?