Part 01- Operating System Lecture for Gate Computer Science- Memory management and it’s application.<\/p>\n
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Memory management is a crucial function of an operating system (OS) that handles the allocation and deallocation of memory for processes. It ensures efficient utilization of memory while preventing conflicts between different programs.<\/p>\n
Single Partition Allocation:<\/strong> Entire memory is given to a single process.<\/p>\n<\/li>\n Multiple Partition Allocation:<\/strong> Memory is divided into fixed or variable-sized partitions.<\/p>\n Fixed Partitioning:<\/strong><\/p>\n Variable Partitioning:<\/strong><\/p>\n Allows a process to be stored in non-contiguous<\/strong> memory locations, reducing fragmentation.<\/p>\n Paging:<\/strong><\/p>\n Segmentation:<\/strong><\/p>\n Paging + Segmentation (Hybrid Model):<\/strong><\/p>\n Virtual memory allows a computer to run programs larger than the available physical RAM by using swap space<\/strong> on the hard disk.<\/p>\n Working of Virtual Memory:<\/strong><\/p>\n Page Replacement Algorithms:<\/strong><\/p>\n Advantages of Virtual Memory:<\/strong> Operating Systems (Windows, Linux, MacOS):<\/strong> Use paging & segmentation for efficient memory handling. Memory management is essential for ensuring efficient and safe execution of processes in an OS. Techniques like paging, segmentation, and virtual memory<\/strong> help optimize resource utilization and improve system performance.<\/p>\n Would you like a detailed discussion on Paging, Segmentation, or Page Replacement Algorithms<\/strong>?<\/p>\n Certainly! Here’s a structured breakdown of:<\/p>\n Memory management is a core function of the Operating System (OS)<\/strong> that handles:<\/p>\n Allocation<\/strong> and deallocation<\/strong> of memory to various processes.<\/p>\n<\/li>\n Tracking which parts of memory are in use<\/strong> and by whom<\/strong>.<\/p>\n<\/li>\n Deciding which processes to swap in or out<\/strong> from main memory.<\/p>\n<\/li>\n<\/ul>\n Efficient CPU utilization<\/strong><\/p>\n<\/li>\n Fair access<\/strong> for all processes<\/p>\n<\/li>\n Minimizing fragmentation<\/strong><\/p>\n<\/li>\n Ensuring protection and isolation<\/strong> between processes<\/p>\n<\/li>\n<\/ul>\n Each process gets a single contiguous block<\/strong> of memory.<\/p>\n<\/li>\n Drawback:<\/strong> Causes external fragmentation<\/strong>.<\/p>\n<\/li>\n<\/ul>\n Physical memory is divided into fixed-size blocks (frames)<\/strong>.<\/p>\n<\/li>\n Logical memory is divided into pages<\/strong>.<\/p>\n<\/li>\n Pages are mapped to frames using a page table<\/strong>.<\/p>\n<\/li>\n Solves external fragmentation<\/strong> but causes internal fragmentation<\/strong>.<\/p>\n<\/li>\n<\/ul>\n Memory is divided based on logical divisions<\/strong> (code, data, stack).<\/p>\n<\/li>\n Uses segment table<\/strong> to keep track.<\/p>\n<\/li>\n Better for programmer’s view but may cause external fragmentation<\/strong>.<\/p>\n<\/li>\n<\/ul>\n Allows execution of processes not completely loaded<\/strong> in memory.<\/p>\n<\/li>\n Uses paging + disk (swap space)<\/strong>.<\/p>\n<\/li>\n Demand Paging<\/strong> is a popular strategy.<\/p>\n<\/li>\n<\/ul>\n \ud83d\udd38 Page Replacement Algorithms<\/strong> (for GATE):<\/p>\n FIFO<\/p>\n<\/li>\n LRU (Least Recently Used)<\/p>\n<\/li>\n Optimal Page Replacement<\/p>\n<\/li>\n<\/ul>\n Numerical problems<\/strong> on page table translation<\/strong>.<\/p>\n<\/li>\n Calculating page faults<\/strong> using \n
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B. Non-Contiguous Memory Allocation<\/strong><\/h3>\n
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4. Virtual Memory & Its Applications<\/strong><\/h3>\n
What is Virtual Memory?<\/strong><\/h3>\n
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\u00a0Allows execution of large programs.
\u00a0Provides memory isolation<\/strong> for processes.
\u00a0Enables multitasking<\/strong> without requiring large RAM.<\/p>\n5. Applications of Memory Management<\/strong><\/h3>\n
Multitasking Environments:<\/strong> Run multiple applications simultaneously without crashes.
Cloud Computing & Virtualization:<\/strong> Allocate virtual memory for multiple users dynamically.
Embedded Systems:<\/strong> Optimizes memory usage in resource-constrained devices (IoT, mobile OS).<\/p>\nConclusion<\/strong><\/h3>\n
Part 01- Operating System Lecture for Gate Computer Science- Memory management and it’s application.<\/a><\/h3>\n
UNIT NO: – 4 MEMORY MANAGEMENT<\/a><\/h3>\n
OPERATING SYSTEM Lecture Notes On<\/a><\/h3>\n
OPERATING SYSTEMS – MIS<\/a><\/h3>\n
\n\ud83c\udf93 Part 01 \u2013 Operating System Lecture for GATE CSE<\/strong><\/h2>\n
\ud83d\udcd8 Topic: Memory Management and Its Applications<\/strong><\/h3>\n
\n\ud83d\udd39 1. What is Memory Management?<\/strong><\/h2>\n
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\n\ud83d\udd39 2. Goals of Memory Management<\/strong><\/h2>\n
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\n\ud83d\udd39 3. Types of Memory in OS<\/strong><\/h2>\n
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\n \nMemory Type<\/th>\n Description<\/th>\n<\/tr>\n<\/thead>\n \n Main Memory (RAM)<\/strong><\/td>\n Fast, volatile storage for running processes<\/td>\n<\/tr>\n \n Secondary Memory<\/strong><\/td>\n Slower, non-volatile (e.g., HDD\/SSD)<\/td>\n<\/tr>\n \n Cache Memory<\/strong><\/td>\n High-speed memory close to CPU<\/td>\n<\/tr>\n \n Virtual Memory<\/strong><\/td>\n Logical memory abstraction for processes<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
\n\ud83d\udd39 4. Memory Allocation Techniques<\/strong><\/h2>\n
a. Contiguous Allocation<\/strong><\/h3>\n
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b. Paging<\/strong><\/h3>\n
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c. Segmentation<\/strong><\/h3>\n
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\n\ud83d\udd39 5. Virtual Memory<\/strong><\/h2>\n
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\n\ud83d\udd39 6. Fragmentation<\/strong><\/h2>\n
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\n \nType<\/th>\n Cause<\/th>\n Example<\/th>\n<\/tr>\n<\/thead>\n \n External<\/strong><\/td>\n Free spaces scattered<\/td>\n Contiguous allocation<\/td>\n<\/tr>\n \n Internal<\/strong><\/td>\n Wasted space within blocks<\/td>\n Paging<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
\n\ud83d\udd39 7. GATE-Level Applications<\/strong><\/h2>\n
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