CS 347: Operating SystemsCS 347: Operating Systems

In this course, we reason about In this course, we reason about effective performance effective performance of a computer of a computer systemsystem

The emphasis of this course is onThe emphasis of this course is on– ConceptsConcepts– TechniquesTechniques– TechnologyTechnology

Aim of the courseAim of the course

Develop Develop critical thinking critical thinking abilities in abilities in the area of operating systemsthe area of operating systems– So that one can make an intelligent So that one can make an intelligent

choice of operating systems and choice of operating systems and program structures to use for obtaining program structures to use for obtaining effective performance in a specific effective performance in a specific computing environmentcomputing environment

More about critical thinking laterMore about critical thinking later

This is a fun course!This is a fun course! Deals withDeals with - Interesting OS features- Interesting OS features - Contemporary computer architectures- Contemporary computer architectures

And their mutual interactionAnd their mutual interaction

This is a course in which students often know This is a course in which students often know more than the instructor!more than the instructor!

About OS booksAbout OS books Silberschatz, Galvin and Gagne, 7/eSilberschatz, Galvin and Gagne, 7/e - Comprehensive- Comprehensive - Difficult to find some specifics- Difficult to find some specifics

Stallings, 4/eStallings, 4/e - Good engineering book- Good engineering book - Narrow in perspective- Narrow in perspective

Dhamdhere, 3/eDhamdhere, 3/e - Focuses on concepts - Focuses on concepts - Comprehensive- Comprehensive - Includes case studies of Linux, Windows- Includes case studies of Linux, Windows

Book we will useBook we will use

DhamdhereDhamdhere

Operating SystemsOperating Systems

─ ─A Concept-Based Approach, A Concept-Based Approach,

McGraw Hill India, 3/eMcGraw Hill India, 3/e

Evaluation schemeEvaluation scheme

Quizzes (about 6 or so)Quizzes (about 6 or so)

- frequent and surprise quizzes- frequent and surprise quizzes Take home assignments Take home assignments

– 1 large assignment or a few short ones1 large assignment or a few short ones Mid-semester and final examsMid-semester and final exams Indicative weightages:Indicative weightages: Q: 10%, Asgn: 10%, M: 30%, E: 50%Q: 10%, Asgn: 10%, M: 30%, E: 50%

Honesty policyHonesty policy

Highest standards of academic Highest standards of academic honesty are expected and will be honesty are expected and will be enforcedenforced

For take home assignmentsFor take home assignments

- No discussion with others- No discussion with others

- No copying- No copying

Strict action will be taken againstStrict action will be taken against

violators of this policyviolators of this policy

Classroom rulesClassroom rules

Mobile phones should not be usedMobile phones should not be used– Any phone that rings or is used will be Any phone that rings or is used will be

confiscatedconfiscated Punctuality is expectedPunctuality is expected

– Latecomers should not disturb the classLatecomers should not disturb the class– Doors may be closed after start of classDoors may be closed after start of class– XX grades for inadequate attendance XX grades for inadequate attendance

Interaction with instructor a mustInteraction with instructor a must– Ask questions; else I will ask them !Ask questions; else I will ask them !

About Critical thinkingAbout Critical thinking

– Most education systems are fact basedMost education systems are fact basedThey teach you facts and test their recallThey teach you facts and test their recallThey teach you ‘what’ you should think in They teach you ‘what’ you should think in

what situationwhat situation

– They may not teach `how’ to thinkThey may not teach `how’ to think– Students have to figure out the `how’Students have to figure out the `how’

It is an essential skill for scientists and It is an essential skill for scientists and technologiststechnologists

It is the subject matter of It is the subject matter of critical thinkingcritical thinking

Critical thinkingCritical thinking

From wikipediaFrom wikipedia– Critical thinking is purposeful and Critical thinking is purposeful and

reflective judgment about what to reflective judgment about what to believe or what to do in response tobelieve or what to do in response to

ObservationsObservationsExperienceExperienceVerbal or written expressionsVerbal or written expressionsArgumentsArguments

– It is not about passing of It is not about passing of negativenegative comments!comments!

Critical thinkingCritical thinking

Example illustrating its needExample illustrating its need– How to master the vast amount of How to master the vast amount of

information available on the web?information available on the web?One must analyze the information available One must analyze the information available

from multiple sourcesfrom multiple sourcesValidate information from each source, Validate information from each source,

rejecting unreliable/illogical informationrejecting unreliable/illogical informationCorrelate information from various sources Correlate information from various sources

to make a cohesive wholeto make a cohesive whole– Take care of differences in terminologyTake care of differences in terminology

Critical thinkingCritical thinking

Wikipedia (contd): A critical thinkerWikipedia (contd): A critical thinkerRaises vital questions and problems, Raises vital questions and problems,

formulating them clearly and preciselyformulating them clearly and preciselyGathers and assesses relevant informationGathers and assesses relevant informationComes to well-reasoned conclusions and Comes to well-reasoned conclusions and

solutionssolutionsThinks open-mindedly (about alternatives)Thinks open-mindedly (about alternatives)Communicates effectively with others in Communicates effectively with others in

figuring out solutions to complex problems; figuring out solutions to complex problems; without being unduly influenced by otherswithout being unduly influenced by others

Critical thinkingCritical thinking

Critical thinking is a tool of inquiryCritical thinking is a tool of inquiry– Wade (‘55) identified 8 characteristicsWade (‘55) identified 8 characteristics

Asking questionsAsking questionsDefining a problemDefining a problemExamining evidenceExamining evidenceAnalyzing assumptions and biasesAnalyzing assumptions and biasesAvoiding emotional reasoningAvoiding emotional reasoningAvoiding oversimplificationAvoiding oversimplificationConsidering alternative interpretationsConsidering alternative interpretationsTolerating ambiguityTolerating ambiguity

Critical thinkingCritical thinking

Critical thinking is about being both Critical thinking is about being both willing and able to evaluate one’s willing and able to evaluate one’s thinking (wikipedia)thinking (wikipedia)– It helps in all aspects of lifeIt helps in all aspects of life– Core thinking skills are portableCore thinking skills are portable

They can be carried over from one field, They can be carried over from one field, area, or course to anotherarea, or course to another

– You must integrate critical thinking into You must integrate critical thinking into your attitude!your attitude!

Thinking abilities should improve with time!Thinking abilities should improve with time!

Learning and Critical thinkingLearning and Critical thinking

Learning takes place in 2 phasesLearning takes place in 2 phases

(Wikipedia)(Wikipedia)– Learning basic ideas, principles and Learning basic ideas, principles and

theoriestheoriesThe process of internalizationThe process of internalization

– Use the basic ideas, principles and Use the basic ideas, principles and theoriestheories

The process of applicationThe process of application

Thinking skills─what we will doThinking skills─what we will do

– Explicit teaching of thinking skills Explicit teaching of thinking skills Is beyond the scope of this courseIs beyond the scope of this course Is beyond the abilities of this instructorIs beyond the abilities of this instructor

– However, we will facilitate their learning However, we will facilitate their learning in this course throughin this course through

Classroom discussionsClassroom discussionsCreating situations for group thinkingCreating situations for group thinkingStudy literature-and-report assignmentsStudy literature-and-report assignmentsQuizzes and Exams!Quizzes and Exams!

Thinking skills and the ExamsThinking skills and the Exams

Exams will include questions aimed Exams will include questions aimed at exercising/using thinking skillsat exercising/using thinking skills– Performance in these Qs will decide Performance in these Qs will decide

what range of grades you might earnwhat range of grades you might earnE.g., if a student performs poorly in thinking E.g., if a student performs poorly in thinking

oriented Qs, top grades such as AA, AB, BB oriented Qs, top grades such as AA, AB, BB would be denied irrespective of the total would be denied irrespective of the total marks obtained in the coursemarks obtained in the course

Group thinking in the courseGroup thinking in the course

– Groups of approx 10 students each will Groups of approx 10 students each will be formedbe formed

– In every lecture, one of the groups will In every lecture, one of the groups will pose ONE question on the previous pose ONE question on the previous lecture’s contents that requires critical lecture’s contents that requires critical thinkingthinking

Good questions will earn acclaimGood questions will earn acclaim

– Other situations will also be createdOther situations will also be created We will start on it today!We will start on it today!

ConceptsConcepts

Critical thinking and conceptsCritical thinking and concepts– The relationship is two-foldThe relationship is two-fold

Critical thinking helps in concept formation Critical thinking helps in concept formation from available informationfrom available information

Concepts and principles are tools of critical Concepts and principles are tools of critical thinkingthinking

– Concepts enable a person to analyse, assess and Concepts enable a person to analyse, assess and improve thinkingimprove thinking

– Core concepts and principles of analysis existCore concepts and principles of analysis exist– Domain specificDomain specific concepts and principles can also concepts and principles can also

be used in thinkingbe used in thinking

The Concept-Based ApproachThe Concept-Based Approach

In classIn class– We will develop concepts and enunciate We will develop concepts and enunciate

principlesprinciples– We will also use concepts and principles We will also use concepts and principles

in our discussionsin our discussions In assignmentsIn assignments

– You practice use of concepts, principlesYou practice use of concepts, principles In quizzes and examsIn quizzes and exams

– You demonstrate that you can use themYou demonstrate that you can use them

The Concept-Based ApproachThe Concept-Based Approach

Key thinking skills that facilitate Key thinking skills that facilitate learning about complex systemslearning about complex systems– Focusing skillsFocusing skills

Attending to selected pieces of information Attending to selected pieces of information and ignoring othersand ignoring others

– Organizing skillsOrganizing skillsArranging information so that it can be used Arranging information so that it can be used

more effectivelymore effectively

The Concept-Based ApproachThe Concept-Based Approach

Concepts assist in critical thinkingConcepts assist in critical thinking– AbstractionAbstraction aids in focusing aids in focusing– Abstract views Abstract views aid in organizingaid in organizing