Thrashing

Duration: 4 min

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Inside: a video lesson and guided study material.

Module outline

  1. Communication Round: Vocabulary, Subject Verb Agreement (Verb Noun Agreement), Tenses, Comprehension / Reading Comprehension / Unseen Passages (Critical Reasoning) (Paragraph Questions), Cloze Test (Cloze Passage), Sentence Correction (Error Correction), Sentence Completion (Fill in the blanks), Sentence Re-arrangements (Para Jumbles) (Narrative Sequencing), Direct and Indirect Speech, Active Passive Voice (Voice), Verbal Analogy (Word Based Analogy), Articles, Preposition, Conjunction, Sentence Construction, English Writing Ability, Communication Assessment
  2. Quantitative Aptitude: Ratio and Proportion (Ratios), Divisibility Rules, Data Interpretation, Mixture and Alligation, Permutation and Combination, Logarithm, Number System, HCF LCM, Speed Time and Distance, Percentage, Average, Powers and Exponents (Surds and Indices), Time and Work, Mensuration and Geometry, Age Problems, Pipe and Cistern, Probability, Profit and Loss, Simple Interest and Compound Interest, Algebra
  3. Analytical and Logical Reasoning: Series (Number and Letter Series) (Numerical Relations and Reasoning), Coding Decoding, Data Sufficiency, Non Verbal Reasoning (Spatial Aptitude) (Spatial Reasoning) (Visual Reasoning), Directions (Direction Test), Ranking, Order and Sequence, Deductive and Inductive Reasoning (Logical Deduction and Induction) (Prepositional Reasoning), Selection Decision Table (Decision Making), Logical Sequence Of Words, Puzzle Solving (Puzzles), Syllogisms, Seating Arrangements, Calendar, Clock, Blood Relations, Cubes & Dices, Venn Diagram, Analytical Reasoning (Counting Figures Reasoning)
  4. Cognizant Gaming Aptitude: Gamified / Game Based Aptitude
  5. Java (Cluster 1): Java
  6. ANSI SQL MySQL (Cluster 1,2,3): SQL
  7. HTML, CSS, JavaScript (Cluster 1,3): HTML, CSS, JavaScript
  8. Python (Cluster 2): Python for Placements by Yash Sir
  9. Cloud Fundamentals (Cluster 2): Emerging Tech Trends
  10. C# (Cluster 3): C#
  11. OOPs: Object Oriented Programming (OOPS)
  12. Technical Assessment (Coding): Coding Questions by Yash Sir, C Programming by Yash Sir, Programming in C++, Pseudo Codes
  13. Data Structures: Introduction to DS, Array, Stack, Queue, Linked List, Tree, Graphs, Hashing
  14. DBMS: Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, Normalization (1NF - BCNF), Decomposition Properties & 4NF, File Organization & Indexing, Relational Algebra, Relational Calculus, Transaction Management, Concurrency Control, Database Recovery, ORDBMS, Database Security & Authorization, Query Processing & Optimization, Enhanced Data Models, Data Warehousing & Mining, Big Data Systems, NoSQL
  15. Operating Systems: Introduction to OS, Process Management, CPU Scheduling, Process Synchronization, Deadlock, Threads & Process Creation, Memory Management, Virtual Memory, Disc Scheduling, File Management, Windows OS, Linux OS, Security, Distributed Systems, Virtual Machines
  16. 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, Hardware basics, Network Security, Mobile Technology, Cloud Computing and IoT, Cyber and Info Security
AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

This educational video provides a detailed explanation of 'Thrashing' within the context of operating systems. The instructor, Sanchit Jain from Knowledge Gate Educator, utilizes a presentation slide featuring a specific definition and a graphical representation to illustrate the phenomenon. The central theme revolves around the relationship between CPU utilization and the degree of multiprogramming. The slide explicitly defines thrashing as a state where a process spends more time paging than executing. The graph serves as a visual aid to demonstrate how system performance degrades when the degree of multiprogramming exceeds a certain threshold, leading to high paging activity and reduced CPU efficiency.

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The session begins with the instructor introducing the concept of thrashing. The slide text is clearly visible, stating, 'A process is thrashing if it is spending more time paging than executing. High paging activity is called Thrashing.' The instructor stands beside a graph plotting 'CPU utilization' against the 'degree of multiprogramming.' He starts by explaining the initial positive correlation where increasing the number of processes improves CPU usage. To illustrate this progression, he physically draws tick marks on the x-axis of the graph, writing the numbers '1, 2, 3' sequentially. He uses hand gestures to trace the upward slope of the curve, indicating that as more processes are added, the CPU becomes busier and utilization rises.

  2. 2:00 – 3:34 02:00-03:34

    The instructor continues his explanation by extending the x-axis markings to include '4, 5, 6, 7, 8, 9'. He points specifically to the peak of the curve, identifying it as the optimal point for multiprogramming. He then shifts focus to the sharp decline in the graph that occurs after this peak. He explains that once the degree of multiprogramming goes beyond a certain limit (around 6 or 7), the system enters a state of thrashing. To emphasize this critical transition, he draws a red cross or line over the dropping section of the curve. He clarifies that in this region, the CPU utilization drops drastically because the system is overwhelmed with paging activity, spending more time moving data between memory and disk than actually executing instructions.

The lecture successfully bridges the gap between abstract definitions and practical system behavior. By combining the textual definition of thrashing with the graphical drop in CPU utilization, the instructor clarifies that simply adding more processes does not always improve performance. Instead, there is a critical threshold; exceeding it leads to thrashing, where the system becomes inefficient due to excessive paging, resulting in a significant drop in CPU utilization.

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