Virtual memory is a crucial feature of modern operating systems that allows computers to use hard drive space as an extension of (Random Access Memory). This creates a large address space that can be utilized by applications, providing the of a larger memory than physically available. By managing memory more efficiently, virtual memory enhances system stability and multitasking capabilities, enabling multiple applications to run simultaneously without exhausting .
Abstraction of virtual memory provides a simplified view of memory management to . It allows programs to use a large address space, decoupling them from the constraints of physical memory. This abstraction creates a virtual address space for each process, giving the illusion that the process has access to a large and block of memory, even if the actual physical memory is fragmented or limited. Paging is a memory management scheme that eliminates the need for contiguous allocation of physical memory by dividing virtual memory into blocks of physical memory called .
The page table is a crucial data structure used in virtual memory systems, mapping virtual addresses to , allowing the operating system to translate virtual pages used by applications into physical pages in RAM. Each entry in the page table typically contains information such as the frame number in physical memory where the page resides, and for page management, including access permissions and status bits that indicate if the page is in memory or on disk. Despite its benefits, virtual memory can lead to performance degradation due to increased reliance on , which can result in slower access times and potential thrashing, where the system spends more time swapping pages than executing processes.
