Non-Pre-emptive Priority Scheduling

Duration: 12 min

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Inside: a video lesson and guided study material.

Module outline

  1. About Course: About the Course
  2. Section A: General Awareness: Polity, Physics, Biology, Chemistry, Static General Knowledge, History, Geography, Indian Economy, GK- Current Affairs, Evolution of Indian Banking (Banking & Financial Awareness), Environment
  3. Section A: General Intelligence & Reasoning ability: Series (Number and Letter Series) (Numerical Relations and Reasoning), Coding Decoding, Data Sufficiency, Non Verbal Reasoning (Spatial Aptitude) (Spatial Reasoning) (Visual Reasoning), Analytical Reasoning (Counting Figures Reasoning), Blood Relations, Syllogisms, Deductive and Inductive Reasoning (Logical Deduction and Induction) (Prepositional Reasoning), Seating Arrangements, Directions (Direction Test), Puzzle Solving (Puzzles), Calendar, Clock, Cubes & Dices, Selection Decision Table (Decision Making), Logical Sequence Of Words, Crypt Arithmetic, Venn Diagram, Data Arrangement, Inequality, Analogy, Ranking, Order and Sequence, TCS NQT Advanced Reasoning Ability
  4. Section A: Arithmetical & Numerical Ability: Ratio and Proportion (Ratios), Divisibility Rules, Data Interpretation, Mixture and Alligation, Permutation and Combination, Logarithm, Number System, HCF LCM, Sequence and Series (Series), Speed Time and Distance, Percentage, Average, Profit and Loss, Simple Interest and Compound Interest, Time and Work, Pipe and Cistern, Mensuration and Geometry, Powers and Exponents (Surds and Indices), Algebra, Probability, Mental Ability, Age Problems, Partnership, Statistics, Arithmetic, Speed Mathematics and Basic Mathematics, Miscellaneous
  5. Section A: English Language & Comprehension: Vocabulary, Subject Verb Agreement (Verb Noun Agreement), Adjectives, Tenses, Comprehension / Reading Comprehension / Unseen Passages (Critical Reasoning) (Paragraph Questions), Articles, Sentence Construction, Preposition, Direct and Indirect Speech, Sentence Completion (Fill in the blanks), Sentence Re-arrangements (Para Jumbles) (Narrative Sequencing), Modals, Active Passive Voice (Voice), Sentence Correction (Error Correction), Adverb, Conjunction, Cloze Test (Cloze Passage)
  6. Section A: Hindi Language & Comprehension: भाषा, लिपि, ध्वनि, वर्ण, अक्षर, स्वर, व्यंजन, मात्रा और संयुक्ताक्षर, वर्तनी, वर्ण-विन्यास, अनुस्वार, अनुनासिक, चंद्रबिंदु और ‘र’ के रूप, शब्द, पद और शब्द-भेद, संज्ञा और सर्वनाम, विशेषण और क्रिया, लिंग, वचन, पुरुष और कारक, काल, वाच्य, वाक्य और वाक्य-भेद, संधि, समास, विलोम शब्द, पर्यायवाची शब्द, सामान्य अशुद्धियाँ, अनेक शब्दों के लिए एक शब्द, मुहावरे और लोकोक्तियाँ, अपठित गद्यांश और अपठित पद्यांश, Multi-Topic Content (Cross-Concept Material), वर्णमाला
  7. Section B: Programming, Data Structures, OOP & Java: C Fundamentals, Control Flow, Functions, Arrays & Pointers, Storage Classes, Structures & Enums, DMA, Macros, Scoping & File Handling, Introduction to DS, Array, Stack, Queue, Linked List, Tree, Graphs, Hashing, Java, OOPS with C++, Language Design, Intro to Compilers, Visual Basics, Syntax Analysis: Bottom-Up, Object Oriented Technology
  8. Section B: Computer Networks, TCP/IP & Network Security: Introduction to CN, Data Communication, DLL: Flow Control, DLL: Access Control, DLL: Error Control, Data Link Layer - Ethernet, Net Layer: IPv4 & Proto, Net Layer: IP Addressing, Transport Layer Services, TL: Congestion & UDP, Application Layer, Hardware basics, Network Access Technologies, Network Security, Society, Law & Ethics, Mobile Computing, Net Layer:Routing Protocol, Cyber Safety and Security
  9. Section B: Teaching Methodology: Child Development, Concept of Pedagogy, Theories, Inclusive Education, Experiential Pedagogy, Assessment & Evaluation, Curriculum Framework & Reforms, National Education Policy (NEP) 2020, Psychology, Teaching-Learning Process, Personality Development, Teaching Methods & Strategies, Learning and Motivation, Learners & Learning Process, Factors Affecting Teaching, Methods of Teaching, Nature, Objectives & Characteristics of Teaching, Teaching-Learning Aids & ICT Integration, Classroom Management & Communication, Evaluation, Assessment & Measurement, Curriculum & School Environment, Inclusive Education & Special Needs, Professional Development & Ethics
  10. Section B: Digital Electronics / Boolean Logic: Digital Systems & Boolean Basics, Logic Gates & Hardware, Boolean Expression, Boolean Minimization, Combinational Circuit, Sequential Circuits, Number System, Number Representation, Analog-Digital Conversion
  11. Section B: Operating Systems & Linux: Introduction to OS, Process Management, CPU Scheduling, Process Synchronization, Threads & Process Creation, Deadlock, Memory Management, Virtual Memory, File Management, Disc Scheduling, Unix OS, Linux OS, Distributed Systems, Windows OS
  12. Section B: Data Base Management System: Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, Normalization (1NF - BCNF), Decomposition Properties & 4NF, Relational Algebra, SQL, File Organization & Indexing, Transaction Management, Concurrency Control, Database Security & Authorization, Database Recovery, Data Warehousing & Mining
  13. Section B: Internet & Web Technologies: Website, Browser & Services, Internet Fundamentals, Web Design & Development, Protocols & Services, Web Publishing & Hosting, Server Side & Security, HTML Basics, CSS, Emerging Technologies, JavaScript-Basics, .Net Programming, Electronic Data Interchange and E-Commerce, XML
  14. Section B: Computer Fundamentals, IT Basics & Architecture: Basics of COA, Cache Memory Organization, Input Output Organisation, Register Transfer and Microoperations, Control Unit Design, Programming the Basic Computer, Terms & Abbreviations, MS Office Applications, Instr Formats & Modes, Floating Point Rep
  15. Section B: Python Language: Introduction to Python, Tokens, Variables, Data Types, I/O, Operators & Expressions, Control Flow & Looping, Collections & Strings, Functions & Modules, File Handling & Data Analysis
  16. Section B: Software Engineering: Fundamentals of Software Engineering, Software Requirements and Quality Assurance, Software Design, Estimation and Metrics, Software Testing, Software Maintenance and Configuration Management, extras, Fundamentals of Systems and Information Systems
  17. Section B: Design & Analysis of Algorithms: Algorithm Analysis, Time Complexity Analysis, Sorting Algorithms, Greedy Algorithms, Dynamic Programming, Minimum Spanning Trees, Shortest Path Algos, Advanced Algorithms
  18. Section B: Mathematics: Linear Algebra, Calculus, Trigonometry, Vectors, Set Theory, Functions, Relations, Propositional and Predicate Logic, Research Process Steps, Graph Theory
  19. Section B: Computer Graphics, Multimedia & Mobile Computing: Basics of Computer Graphics, 2-D Geometrical Transforms and Viewing, 3-D Object Representation, Geometric Transformations and Viewing, Multimedia
  20. Section B: Emerging Trends: Emerging Tech Trends, Knowledge Representation, Natural Language Processing
  21. DSSSB Previous Year Paper:
  22. Business Studies and Management: Business Communication, Business Organization and Management, Financial Accounting, Business Economics, Management Information System (MIS), Knowledge Management & New Economy
AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

This educational video provides a comprehensive lecture on Priority Scheduling in Operating Systems. The instructor begins by defining the algorithm, explaining that each process is assigned a priority number, and the CPU is allocated to the process with the highest priority. He clarifies that 'highest priority' can be represented by either the highest or lowest number depending on the system's convention. The lecture covers tie-breaking mechanisms using First-Come-First-Served (FCFS) order and notes that the algorithm supports both pre-emptive and non-pre-emptive versions. The second half of the video features a detailed numerical example involving six processes (P0 to P5). The instructor constructs a Gantt chart to determine the execution sequence based on priority values and arrival times. He then calculates the Completion Time (CT), Turn Around Time (TAT), and Waiting Time (WT) for each process using standard formulas, filling out a data table to demonstrate the final results.

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The instructor introduces the concept of Priority Scheduling. The slide text states: 'Here a priority is associated with each process. At any instance of time out of all available process, CPU is allocated to the process which possess highest priority (may be higher or lower number).' He explains that a priority number is assigned to every process. He writes 'P1 - 5' and 'P2 - 3' on the screen to illustrate that priority is just a number. He mentions that if priorities are equal, the tie is broken using FCFS order. He also states that there is no importance to seniority or burst time in this algorithm.

  2. 2:00 – 5:00 02:00-05:00

    The instructor elaborates on the characteristics of Priority Scheduling. He draws a diagram of a queue to visualize how processes wait. He emphasizes that the algorithm supports both non-pre-emptive and pre-emptive versions. He explains that the CPU is always given to the process with the highest priority among the available ones. He clarifies that 'highest priority' might mean the highest number (e.g., 8 is higher than 5) or the lowest number (e.g., 1 is higher than 5), depending on the specific implementation. He reiterates that burst time does not influence the scheduling decision, only the priority value matters.

  3. 5:00 – 10:00 05:00-10:00

    The lecture transitions to a numerical example. A table appears with columns: P. No, AT (Arrival Time), BT (Burst Time), Priority, CT, TAT, and WT. The data includes processes P0 through P5 with varying priorities. P3 has a priority of 8(H), indicating High priority. The instructor draws a Gantt chart at the bottom of the screen. He determines the execution order: P0 starts at t=1. At t=5, P3 (Priority 8) is selected. At t=10, P2 (Priority 7) is selected. At t=13, P5 (Priority 6) is selected. For P1 and P4, which both have Priority 5, he applies FCFS, so P1 runs before P4. He writes the sequence P0, P3, P2, P5, P1, P4 on the timeline.

  4. 10:00 – 11:39 10:00-11:39

    The instructor completes the numerical solution by calculating the metrics for each process. He fills the CT column: P0=5, P3=10, P2=13, P5=15, P1=17, P4=18. He then calculates TAT using the formula 'TAT = CT - AT'. For P0, TAT is 5-1=4. For P1, TAT is 17-2=15. He proceeds to calculate WT using 'WT = TAT - BT'. For P0, WT is 4-4=0. For P1, WT is 15-2=13. He fills the entire table row by row, pointing to the values and explaining the arithmetic for each process to ensure students understand how the final metrics are derived from the Gantt chart.

The video effectively bridges theory and practice in Priority Scheduling. It starts by establishing the core rule: CPU allocation is driven by priority numbers, not burst time or arrival time, though arrival time dictates availability. The instructor clarifies the ambiguity of 'highest priority' (high number vs low number) and the role of FCFS in tie-breaking. The practical application involves a step-by-step execution of a Gantt chart where the scheduler dynamically picks the highest priority process available at each time unit. The final segment focuses on performance evaluation, calculating Turn Around Time and Waiting Time for each process, reinforcing the formulas TAT = CT - AT and WT = TAT - BT. This progression ensures students understand both the logic of the scheduler and the method for evaluating its efficiency.

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