Round Robin Advantage Vs Disadvantage

Duration: 9 min

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Module outline

  1. About the Course: About the Course
  2. Section 1 | Language (Hindi): 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
  3. Section 1 | Language (उर्दू भाषा — 22 प्रश्न (निश्चित)): Spelling & Diacritics, Grammar (اسم, فعل, صفت, ضمیر), Vocabulary, Idioms & Proverbs, Comprehension
  4. Section 1 | Language (বাংলা / बांग्ला भाषा — 22 प्रश्न (निश्चित)): Bangla Script and Sounds, Bangla Grammar and Usage, Bangla Word Formation and Vocabulary, Reading and Text Interpretation
  5. Section 1 | Language (English): Vocabulary, Noun, Subject Verb Agreement (Verb Noun Agreement), Adjectives, Tenses, Pronoun, Verb, Adverb, Preposition, Articles, Determiner, Conjunction, Modals, Active Passive Voice (Voice), Direct and Indirect Speech, Sentence Correction (Error Correction), Sentence Completion (Fill in the blanks), Sentence Construction, Sentence Re-arrangements (Para Jumbles) (Narrative Sequencing), Comprehension / Reading Comprehension / Unseen Passages (Critical Reasoning) (Paragraph Questions), Cloze Test (Cloze Passage), Verbal Analogy (Word Based Analogy), Facts, Inference and Judgements
  6. Section 2 | Primary Maths & Reasoning: Ratio and Proportion (Ratios), Divisibility Rules, Mixture and Alligation, Permutation and Combination, Number System, HCF LCM, Sequence and Series (Series), Speed Time and Distance, Series (Number and Letter Series) (Numerical Relations and Reasoning), Coding Decoding, Non Verbal Reasoning (Spatial Aptitude) (Spatial Reasoning) (Visual Reasoning), Percentage, Average, Profit and Loss, Simple Interest and Compound Interest, Time and Work, Mensuration and Geometry, Age Problems, Arithmetic, Powers and Exponents (Surds and Indices), Algebra, Probability, Trigonometry, Syllogisms, Seating Arrangements, Blood Relations, Directions (Direction Test), Analytical Reasoning (Counting Figures Reasoning), Puzzle Solving (Puzzles), Calendar, Clock, Cubes & Dices, Venn Diagram, Data Arrangement, Inequality, Analogy, Ranking, Order and Sequence
  7. Section 2 | General Awareness (GK + Current Affairs): Polity, Physics, Biology, State Wise GK, Chemistry, History, Geography, Indian Economy, Environment, GK- Current Affairs, Static General Knowledge
  8. Section 3 | Computer System and Org. (CSO): Basics of COA, Floating Point Rep, Cache Memory Organization, Instr Formats & Modes, Programming the Basic Computer, Input Output Organisation, Register Transfer and Microoperations, Control Unit Design
  9. Section 3 | Database Management System: Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, Normalization (1NF - BCNF), Decomposition Properties & 4NF, SQL, File Organization & Indexing, Relational Algebra, Relational Calculus, Transaction Management, Concurrency Control
  10. Section 3 | Operating System: Introduction to OS, Process Management, CPU Scheduling, Threads & Process Creation, Memory Management, Virtual Memory, Disc Scheduling, File Management, Process Synchronization
  11. Section 3 | Computer Networks: Introduction to CN, Data Communication, DLL: Access Control, DLL: Flow 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
  12. Section 3 | Data Structures: Introduction to DS, Array, Stack, Queue, Linked List, Tree, Graphs, Hashing, Algorithm Analysis, Time Complexity Analysis, Sorting Algorithms, Greedy Algorithms, Minimum Spanning Trees, Shortest Path Algos
  13. Section 3 | Theory Of Computation & Compiler Design: Introduction to TOC, Deterministic FA (DFA), Non-Deterministic FA, Regular Expressions, Grammar, Regular Language Properties, Moore & Mealy Machines, Pushdown Automata & CFG, Turing Machines, Intro to Compilers, Lexical Analysis, Grammar & CFG, Syntax Analysis: Top-Down, Syntax Analysis: Bottom-Up, Semantic Analysis & SDT, Intermediate Code Gen, Code Optimization
  14. Section 3 | Emerging Trends (AI, Societal Ethics & MS Office): Artificial Intelligence, Emerging Tech Trends, Society, Law & Ethics, MS Office Applications
  15. Section 3 | Software Engineering: Fundamentals of Software Engineering, Software Requirements and Quality Assurance, Software Design, Estimation and Metrics, Software Maintenance and Configuration Management, Software Testing
  16. Section 3 | C Programming: C Fundamentals, Control Flow, Functions, Arrays & Pointers, Storage Classes, Structures & Enums, DMA, Macros, Scoping & File Handling
  17. Section 3 | OOPS, C++, JAVA, HTML: OOPS with C++, Java, HTML Basics, CSS
  18. Section 3 | Java: Java Fundamentals, Array, String, IO & References
  19. Section 3 | Python: Introduction to Python, Tokens, Variables, Data Types, I/O, Operators & Expressions, Control Flow & Looping, Collections & Strings, Functions & Modules, File Handling & Data Analysis
  20. Section 3 | Digital Electronics: Digital Systems & Boolean Basics, Logic Gates & Hardware, Boolean Expression, Boolean Minimization, Combinational Circuit, Sequential Circuits, Number System, Number Representation
  21. Section 3 | Multimedia: Multimedia
  22. BPSC Previous Year Papers:
  23. BPSC Full Mock Tests:
AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

This educational video provides a comprehensive lecture on the Round Robin (RR) CPU scheduling algorithm. The instructor begins by explaining the core principles of RR, including the concept of a time quantum (q) and how it ensures fairness by giving each of the n processes in the ready queue a turn to execute for at most q time units. A key point is that the maximum waiting time for a process before its next quantum is (n-1)q. The lecture then transitions to the impact of the time quantum's size, explaining that a very large quantum makes RR behave like First-Come, First-Served (FCFS), while a very small quantum creates the illusion of multiple processors, a concept known as processor sharing. The video concludes with a detailed analysis of RR's advantages and disadvantages. Advantages include excellent average response time, making it ideal for time-sharing and interactive systems, and its nature as a preemptive SJF implementation. Disadvantages include the potential for longer processes to starve and the fact that performance is highly sensitive to the time quantum's value, as it affects both average response time and CPU utilization. A table of process metrics is used to illustrate the calculation of completion time, turn around time, and waiting time.

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The video opens with a slide defining the Round Robin (RR) scheduling algorithm. The instructor explains that if there are n processes in the ready queue and the time quantum is q, each process gets 1/n of the CPU time in chunks of at most q time units. He emphasizes that each process must wait no longer than (n-1)q time units for its next quantum. To illustrate this, he draws a timeline on the whiteboard, labeling processes P1, P2, and P3, and shows how they would be scheduled in a round-robin fashion, with each getting a slice of time q. He also writes the formula for the maximum waiting time as (n-1)q.

  2. 2:00 – 5:00 02:00-05:00

    The instructor discusses the effect of the time quantum's size. He states that if the time quantum is extremely large, RR behaves like the FCFS policy. Conversely, if the time quantum is extremely small (e.g., 1 millisecond), the RR approach is called processor sharing, where it creates the illusion that each of the n processes has its own processor running at 1/n the speed of the real processor. He draws a diagram to show the transition from a large quantum (max) leading to FCFS to a small quantum (min) leading to processor sharing. He also mentions that the effect of context switching on performance must be considered.

  3. 5:00 – 8:37 05:00-08:37

    The video presents a slide on the advantages and disadvantages of RR. Advantages include performing best in terms of average response time, making it suitable for time-sharing, client-server, and interactive systems, and being a kind of SJF implementation. The instructor then moves to the disadvantages: longer processes may starve, and performance is heavily dependent on the time quantum. He explains that a very small quantum gives a good average response time but causes many context switches, while a very large quantum results in poor average response time but fewer context switches and better CPU utilization. The video concludes with a table showing process metrics (P0 to P5) and a Gantt chart, which the instructor uses to calculate completion time, turn around time (TAT = CT - AT), and waiting time (WT = TAT - BT).

The lecture systematically builds an understanding of the Round Robin scheduling algorithm. It starts with the fundamental definition and fairness guarantee, using a timeline diagram to visualize the process. It then explores the critical parameter of the time quantum, showing how its size dictates the algorithm's behavior, from FCFS to processor sharing. Finally, it provides a balanced view by outlining the key advantages, such as excellent response time for interactive systems, and the main disadvantages, including starvation and the trade-off between response time and CPU utilization. The use of a process table and Gantt chart provides a practical example of how to calculate key performance metrics, reinforcing the theoretical concepts.

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