C-Look Scheduling

Duration: 2 min

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Inside: a video lesson and guided study material.

Module outline

  1. Section A | English: Vocabulary, Comprehension / Reading Comprehension / Unseen Passages (Critical Reasoning) (Paragraph Questions), Preposition, Sentence Correction (Error Correction), Sentence Completion (Fill in the blanks), Articles, Sentence Re-arrangements (Para Jumbles) (Narrative Sequencing), Verbal Analogy (Word Based Analogy)
  2. Section A | Quant Aptitude: Ratio and Proportion (Ratios), Mixture and Alligation, Permutation and Combination, Number System, HCF LCM, Sequence and Series (Series), Speed Time and Distance, Arithmetic, Algebra, Powers and Exponents (Surds and Indices), Average, Age Problems, Percentage, Profit and Loss, Partnership, Time and Work, Simple Interest and Compound Interest, Mensuration and Geometry, Probability, Pipe and Cistern
  3. Section A | Reasoning: Series (Number and Letter Series) (Numerical Relations and Reasoning), Coding Decoding, Data Sufficiency, Calendar, Clock, Blood Relations, Directions (Direction Test), Seating Arrangements, Ranking, Order and Sequence, Puzzle Solving (Puzzles)
  4. Section B | C Programming: C Programming by Yash Sir, Coding Questions by Yash Sir
  5. Section B | Data Structures: Algorithm Analysis, Greedy Algorithms, Time Complexity Analysis, Sorting Algorithms, Introduction to DS, Array, Stack, Queue, Linked List, Tree, Graphs
  6. Section B | OOP (C++): Object Oriented Programming (OOPS), Programming in C++
  7. Section B | OS: Introduction to OS, Process Management, CPU Scheduling, Process Synchronization, Threads & Process Creation, Deadlock, Memory Management, Virtual Memory, Disc Scheduling, File Management, Windows OS
  8. Section B | Networking: 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
  9. Section B | AI & Big Data Basics: AI & ML by Arun Sir, Big Data Systems
  10. Section C | Digital Electronics: Digital Systems & Boolean Basics, Logic Gates & Hardware, Boolean Expression, Boolean Minimization, Combinational Circuit, Sequential Circuits, Number System, Number Representation, Analog-Digital Conversion
  11. Section A, C | Comp. Fundamentals, COA: Basics of COA, Floating Point Rep, Cache Memory Organization, Input Output Organisation, Pipelining, Instr Formats & Modes, Control Unit Design, Register Transfer and Microoperations, Multiprocessors, Programming the Basic Computer
  12. MOCK TEST:
AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

This educational video provides a detailed explanation of the C-LOOK disk scheduling algorithm, positioning it within the context of other scheduling methods like SCAN, LOOK, and C-SCAN. The lecture begins by defining C-LOOK through on-screen text, stating that it functions similarly to how LOOK relates to SCAN. Specifically, the disk arm in C-LOOK does not travel to the physical end of the disk; instead, it services the last request in the current direction and then jumps to the last request at the other end. This mechanism is designed to prevent extra delays caused by unnecessary traversal to the disk's physical limits. The instructor then breaks down the pros and cons, noting that C-LOOK offers more uniform wait times and better response times compared to LOOK. However, it incurs higher overhead to find the last request and is generally not recommended for high-load scenarios. The visual aids help clarify these abstract concepts for students.

Chapters

  1. 0:00 – 1:55 00:00-01:55

    The instructor starts by reading the definition of C-LOOK from the slide, emphasizing its relationship to C-SCAN. He then draws a diamond-shaped diagram on the whiteboard to visually connect the four algorithms: SCAN, LOOK, C-SCAN, and C-LOOK, illustrating their structural similarities. Following this, he draws a large circle to represent the disk platter and sketches a line inside it to demonstrate the head movement. He points to the "Advantage" section, highlighting that C-LOOK provides more uniform wait times and better response times compared to LOOK. He then moves to the "Disadvantage" section, explaining that the overhead to find the last request and return to the initial position is higher, making it unsuitable for cases with more load. Throughout the video, he uses hand gestures to emphasize the movement of the disk arm and the logic behind the algorithm's efficiency. He specifically underlines the text regarding overhead and load conditions to stress the limitations of the algorithm in heavy usage scenarios.

The lecture effectively bridges the gap between theoretical definitions and practical visualization. By drawing diagrams and referencing specific slide text, the instructor clarifies how C-LOOK optimizes disk access by avoiding full traversals, while also acknowledging the computational cost involved in managing request boundaries.

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