Non-Pre-emptive Priority Scheduling

Duration: 12 min

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Inside: a video lesson and guided study material.

Module outline

  1. About the course: About the Course
  2. Mathematical Aptitude: संख्या पद्धति / Number System, महत्तम समापवर्तक और लघुत्तम समापवर्त्य / HCF and LCM, Divisibility Rules, प्रतिशत / Percentage, अनुपात और समानुपात / Ratio and Proportion, औसत / Average, लाभ, हानि और बट्टा / Profit, Loss and Discount, समय और कार्य / Time and Work, घन क्षेत्रमिति / Solid Mensuration, साधारण और चक्रवृद्धि ब्याज / Simple and Compound Interest, समय, चाल और दूरी / Time, Speed and Distance, Age Problems, मिश्रण और एलिगेशन / Mixture and Alligation, Algebra, सरलीकरण, घातांक और करणी / Simplification, Indices and Surds, Pipe and Cistern, Trigonometry, Statistics, आँकड़ा निर्वचन / Data Interpretation, Arithmetic, समुच्चय, संबंध, फलन और विविक्त गणित / Sets, Relations, Functions and Discrete Mathematics, संख्या पद्धति और संख्या सिद्धांत / Number Systems and Number Theory, निर्देशांक ज्यामिति, सदिश और त्रिविमीय ज्यामिति / Coordinate Geometry, Vectors and 3D Geometry, बहुपद, समीकरण और सम्मिश्र संख्याएँ / Polynomials, Equations and Complex Numbers
  3. Logical Reasoning: श्रेणी / Series, कूट लेखन एवं कूट वाचन / Coding-Decoding, सादृश्यता एवं वर्गीकरण / Analogy and Classification, रक्त संबंध / Blood Relations, दिशा एवं दूरी / Direction and Distance, क्रम एवं रैंकिंग / Order and Ranking, अशाब्दिक तर्क / Non-Verbal Reasoning, बैठक व्यवस्था एवं पहेलियाँ / Seating Arrangement and Puzzles, Syllogisms, वेन आरेख, न्याय वाक्य एवं असमानता / Venn Diagrams, Syllogism and Inequalities, गणितीय संक्रियाएँ एवं लुप्त संख्या / Mathematical Operations and Missing Numbers, वर्णमाला एवं संख्या परीक्षण / Alphabet and Number Test, कथन आधारित तार्किक विवेचन / Statement-Based Reasoning, Analytical Reasoning (Counting Figures Reasoning), घन, पासा एवं आकृतियों की गिनती / Cubes, Dice and Figure Counting, कैलेंडर एवं घड़ी / Calendar and Clock, Clock
  4. General Knowledge: वैज्ञानिक उपलब्धियाँ और अनुसंधान / Scientific Achievements and Research, Chemistry, Biology, History, Geography, Polity, Indian Economy, समसामयिकी / Current Affairs, Static General Knowledge
  5. Art of Teaching: शिक्षण-अधिगम प्रक्रिया एवं कक्षा प्रबंधन / Teaching-Learning Process and Classroom Management, Learners & Learning Process, Factors Affecting Teaching, शिक्षण विधियाँ एवं उपागम / Teaching Methods and Approaches, सूक्ष्म शिक्षण एवं कक्षा संप्रेषण / Microteaching and Classroom Communication, शिक्षण सहायक सामग्री एवं शैक्षिक तकनीकी / Teaching Aids and Educational Technology, आकलन एवं मूल्यांकन / Assessment and Evaluation, शिक्षक: गुण, व्यावसायिक नैतिकता एवं विकास / Teacher: Qualities, Professional Ethics and Development, शैक्षिक नीतियाँ, अधिनियम एवं प्रशासन / Educational Policies, Acts and Administration, पाठ्यचर्या, कला एवं सह-शैक्षिक क्षेत्र / Curriculum, Arts and Co-curricular Areas, निर्देशन एवं परामर्श / Guidance and Counselling, दिव्यांग बच्चों की शिक्षा / Education of Children with Disabilities, Micro-Teaching & Teaching Skills, पाठ योजना / Lesson Planning
  6. Environmental Science: Environment
  7. Unit 1 | Digital Electronics: Digital Systems & Boolean Basics, Logic Gates & Hardware, Boolean Expression, Boolean Minimization, Combinational Circuit, Sequential Circuits, Number System, Number Representation
  8. Unit 2 | COA: Basics of COA, Floating Point Rep, Cache Memory Organization, Input Output Organisation, Instr Formats & Modes, Control Unit Design, Register Transfer and Microoperations, Programming the Basic Computer
  9. Unit 3 | C Programming: C Fundamentals, Control Flow, Functions, Arrays & Pointers, Storage Classes, Structures & Enums, DMA, Macros, Scoping & File Handling
  10. Unit 3 | Data Structures: Introduction to DS, Array, Stack, Queue, Linked List, Tree, Graphs, Hashing
  11. Unit 4 | Algorithms: Algorithm Analysis, Time Complexity Analysis, Sorting Algorithms, Dynamic Programming, Minimum Spanning Trees, Shortest Path Algos, Advanced Algorithms
  12. Unit 5 | Operating System: Introduction to OS, Process Management, CPU Scheduling, Process Synchronization, Threads & Process Creation, Deadlock, Memory Management, Virtual Memory, Disc Scheduling, File Management
  13. Unit 6 | Database Management System: Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, Normalization (1NF - BCNF), Decomposition Properties & 4NF, File Organization & Indexing, Relational Algebra, SQL, Transaction Management, Concurrency Control
  14. Unit 7 | Computer Networks: Introduction to CN, Data Communication, DLL: Access Control, DLL: Flow Control, DLL: Error Control, DLL: Framing, Data Link Layer - Ethernet, Net Layer: IPv4 & Proto, Net Layer: IP Addressing, Net Layer:Routing Protocol, Transport Layer Services, TL: Congestion & UDP, Application Layer
  15. Unit 8 | Software Engineering: Fundamentals of Software Engineering, Software Requirements and Quality Assurance, Software Design, Estimation and Metrics, Software Testing, Software Maintenance and Configuration Management
  16. Unit 9 | Object Oriented Programming: OOPS with C++
  17. Unit 10 | Web Development: HTML Basics, CSS, JavaScript-Basics, XML, Node.js
  18. Unit 11 | Theory Of Computation: Introduction to TOC, Deterministic FA (DFA), Non-Deterministic FA, Regular Expressions, Grammar, Regular Language Properties, Moore & Mealy Machines, Pushdown Automata & CFG, Turing Machines
  19. Unit 12 | IoT: Emerging Tech Trends, Cloud Computing, कंप्यूटर नेटवर्क / Computer Networks
  20. Unit 13 | Artificial Intelligence: Approaches to AI, Search Algorithms, Game Playing, Knowledge Representation, Natural Language Processing, Artificial Neural Networks, Genetic Algorithms
  21. Unit 14 | E-Commerce: Electronic Data Interchange and E-Commerce, Role of Internet and Web Services, Security in Mobile and Wireless Computing, Physical Security and Cryptography Basics, Cyber Safety and Security
  22. Unit 15 | Multimedia: Multimedia
  23. Unit 16 | Python: Introduction to Python, Tokens, Variables, Data Types, I/O, Operators & Expressions, Control Flow & Looping, Collections & Strings, Functions & Modules, File Handling & Data Analysis, DSA using Python
  24. Full Length Mock Tests — General Paper:
  25. Full Length Mock Tests — Computer Science (Paper II):
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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