Os Memory Management Questions Medium
The purpose of a memory management unit (MMU) is to handle the translation between virtual memory addresses used by the operating system and the physical memory addresses used by the hardware. It is responsible for managing the memory hierarchy, which includes the main memory (RAM) and secondary storage (hard disk or SSD).
The MMU plays a crucial role in memory management by providing memory protection, virtual memory, and memory allocation.
1. Memory Protection: The MMU ensures that each process running on the system has its own isolated memory space, preventing one process from accessing or modifying the memory of another process. It enforces memory access permissions, such as read-only or read-write, to maintain the integrity and security of the system.
2. Virtual Memory: The MMU enables the concept of virtual memory, which allows the operating system to allocate more memory to processes than physically available. It achieves this by utilizing secondary storage as an extension of the main memory. The MMU translates virtual addresses to physical addresses, allowing the operating system to load and unload data from secondary storage as needed, thereby providing an illusion of a larger memory space.
3. Memory Allocation: The MMU manages the allocation and deallocation of memory resources to processes. It keeps track of the available memory blocks and assigns them to processes when requested. When a process terminates or releases memory, the MMU updates the memory allocation table accordingly, making the freed memory available for future allocations.
Overall, the MMU acts as a bridge between the virtual memory space used by the operating system and the physical memory space used by the hardware, ensuring efficient and secure memory management in an operating system.