https://drive.google.com/file/d/1MG-wYUjBZyfIfk8Z1rWHCMrg2tobkFps/view?usp=sharing
This document provides an overview of essential memory management concepts in Operating Systems, starting with the distinction between logical (virtual) and physical addresses. It details the role of the Memory-Management Unit (MMU) in mapping virtual to physical addresses, often using a relocation register. Key memory management techniques are explained, including swapping, which temporarily moves processes between main memory and a backing store. The text covers contiguous memory allocation, which includes fixed-sized partitions (equal and unequal) and dynamic partitioning, introducing the problems of internal and external fragmentation.
Furthermore, the document explains paging, a scheme that allows a process's physical address to be noncontiguous, using a page table for mapping. It discusses hardware support for paging, such as the Translation Look-aside Buffer (TLB), and delves into virtual memory, demand paging, and various page replacement algorithms like FIFO, Optimal, and LRU. Finally, it touches on the concept of thrashing and strategies to prevent it, such as the working-set model.
5 Key Topics and Definitions:
Furthermore, the document explains paging, a scheme that allows a process's physical address to be noncontiguous, using a page table for mapping. It discusses hardware support for paging, such as the Translation Look-aside Buffer (TLB), and delves into virtual memory, demand paging, and various page replacement algorithms like FIFO, Optimal, and LRU. Finally, it touches on the concept of thrashing and strategies to prevent it, such as the working-set model.
5 Key Topics and Definitions:
- Logical Address (Virtual Address): A reference to a memory location that is independent of the current assignment of data to memory and is generated by the CPU.
- Swapping: A process is temporarily moved out of memory to a backing store and then brought back into memory for continued execution.
- Paging: A memory-management scheme that allows the physical address of a process to be noncontiguous, dividing logical memory into fixed-size blocks called pages and physical memory into frames.
- Translation Look-aside Buffer (TLB): A special small, fast-lookup hardware cache used to speed up the memory access process in paging by storing a few page-table entries.
- Demand Paging: A technique in virtual memory management where pages are initially loaded into memory only as they are needed, utilizing a "lazy swapper".
Comments