Paging

• Paging is a memory-management scheme that permits the physical address space of a process to be non-contiguous.
• Paging avoids the considerable problem of fitting memory chunks of varying sizes onto the backing store.
• The backing store also has the fragmentation problems discussed in connection with main memory, except that access is much slower, so compaction is impossible.
• Because of its advantages over earlier methods, paging in its various forms is commonly used in most OSs.
• Traditionally, support for paging has been handled by hardware. However, recent designs have implemented paging by closely integrating the hardware and OS, especially on 64-bit microprocessors.