In order to understand the concept of OS physical and logical address space, it is important to first grasp the fundamentals of memory management in an operating system. Memory management plays a crucial role in any computer system, as it is responsible for allocating and managing memory resources efficiently.
The physical address space refers to the actual physical memory locations in the computer’s hardware. These memory locations are identified by unique physical addresses, which are typically represented in binary form. The physical address space is finite and limited by the hardware architecture of the computer system.
On the other hand, the logical address space is the address space that a process sees and uses. It is a virtual address space that is independent of the actual physical memory locations. The logical address space is divided into fixed-size blocks called pages, which are typically 4KB in size. Each page is assigned a unique logical address, which is used by the process to access the corresponding physical memory location.
The operating system plays a vital role in managing the mapping between the logical and physical address spaces. It uses a data structure called the page table to keep track of the mapping between logical and physical addresses. The page table contains entries that map logical addresses to physical addresses, allowing the operating system to translate a process’s logical address to the corresponding physical address.
When a process requests memory, it is allocated a portion of the logical address space. The operating system then maps this logical address space to available physical memory locations. This mapping is dynamic and can change over time as processes are created, terminated, or require more memory.
One of the key benefits of using logical address spaces is the concept of memory protection. Each process is isolated in its own logical address space, preventing it from accessing the memory of other processes. This ensures that processes cannot interfere with or corrupt each other’s memory, enhancing system stability and security.
In conclusion, understanding the concept of OS physical and logical address space is crucial for comprehending memory management in an operating system. The physical address space represents the actual physical memory locations, while the logical address space is a virtual address space that processes use. The operating system manages the mapping between these two address spaces, ensuring efficient memory allocation and protection.