What Is Memory Management In Operating System?
Do you ever wonder how your computer is able to multitask and handle so many different programs at once? It’s all thanks to memory management in the operating system! But what exactly is memory management, and how does it work? In this blog post, we’ll dive into the world of memory allocation, virtual memory, and page replacement algorithms. So grab a cup of coffee (or tea) and let’s get started on unraveling the mystery behind this crucial aspect of modern computing.
Memory Management in Operating Systems
Memory management in operating systems refers to the process of allocating and managing memory resources for computers. Memory management is essential for effective computer performance, especially when multiple programs are running at the same time.
In order to manage memory effectively, an operating system must first identify which processes need access to specific pieces of memory. It then must determine the size and type of memory required by each process. Finally, it must allocate space in the physical memory address space to store the data and instructions needed by the process.
Some common memory management techniques used by operating systems include:
-Mapping: The operating system creates a virtual address space for each process, which refers to real addresses located on disk or within RAM. The virtual address space is mapped into the real address space at runtime. When a process requests data from another process, the OS uses virtual addresses to fetch that data from disk or RAM.
-Paging: Whenever a page (a section of physical memory) becomes too large to be allocated using mapping or kernal segmentation, the OS swaps out one page for another in order to keep all active processes running in physical memory. This technique is usually implemented as an interrupt service routine (ISR).
-Kernel segmentation: The kernel manages allocating and referencing segments (also called kernel pages) within physicalmemory according to task requirements. Segments are used by various modules within the kernel, including networking drivers and device drivers.
Types of Memory Management
Memory management in an operating system refers to the ways in which an operating system manages the physical memory resources of a computer. Memory management is important because it determines how much data can be stored in RAM and on hard drives, and it allows an operating system to swap out running applications and libraries so that they can use more memory.
In most contemporary operating systems, memory management is done by individual processes, called processes or threads. A process is a single instance of a program that runs on a computer. A thread is a sequence of instructions that are executed by a process. When one process creates another process, it does so by allocating space in memory for the new process and for its own code and data. The new process then starts executing at the point where the old process finished executing.
Most modern operating systems also support thread-level parallelism, which means that multiple threads can run concurrently within a single process. In this case, each thread has its own address space, so you can’t access variables or other objects from other threads without using special library functions.
Techniques Used for Memory Management
Memory management in an operating system refers to the techniques used by the system to manage and use the memory of the system, both volatile (memory which can be lost when power is turned off) and persistent (memory which can remain even after the system is turned off).
The traditional model for memory management in an operating system was called paging. In this model, the operating system would page (copy) frequently accessed memory regions from disk to RAM in order to improve performance. Paging became increasingly inefficient as computer systems got larger and more memory-intensive, due to the additional overhead required to maintain multiple copies of large data structures in RAM.
Modern memory management models largely abandoned paging in favor of a hybrid approach that combines features of both paging and revisioning. In this model, the operating system maintains a small number of “page tables” that track which regions of RAM are currently in use. When a process requests access to a region of RAM that is not currently in use by any other process, the OS checks to see if there is already a page table entry for that address. If there isn’t, the OS creates a new page table entry and assigns it to the process’s address space. If there is already an existing page table entry for that address, then the OS uses that table instead.
Hybrid memory management has several advantages over either pure paging or revisioning: it allows processes to share access to large chunks of memory without interfering with each other
Conclusion
Memory management in operating system is an important task to accomplish. Operating systems manage the resources allocated to processes by allocating and deallocating memory, virtual address spaces, file handles and so on. This article has explained the different types of memory management algorithms used in modern operating systems.
