Search results
Results From The WOW.Com Content Network
In computer operating systems, memory paging (or swapping on some Unix-like systems) is a memory management scheme by which a computer stores and retrieves data from secondary storage [a] for use in main memory. [1] In this scheme, the operating system retrieves data from secondary storage in same-size blocks called pages.
In operating systems that are not single address space operating systems, address space or process ID information is necessary so the virtual memory management system knows what pages to associate to what process. Two processes may use two identical virtual addresses for different purposes.
A system with a smaller page size uses more pages, requiring a page table that occupies more space. For example, if a 2 32 virtual address space is mapped to 4 KiB (2 12 bytes) pages, the number of virtual pages is 2 20 = (2 32 / 2 12). However, if the page size is increased to 32 KiB (2 15 bytes), only 2 17 pages are required. A multi-level ...
A 68451 MMU, which could be used with the Motorola 68010. A memory management unit (MMU), sometimes called paged memory management unit (PMMU), [1] is a computer hardware unit that examines all memory references on the memory bus, translating these requests, known as virtual memory addresses, into physical addresses in main memory.
With software-managed TLBs, a TLB miss generates a TLB miss exception, and operating system code is responsible for walking the page tables and finding the appropriate page table entry. The operating system then loads the information from that page table entry into the TLB and restarts the program from the instruction that caused the TLB miss.
In protected mode with paging enabled (bit 31, PG, of control register CR0 is set), but without PAE, x86 processors use a two-level page translation scheme. Control register CR3 holds the page-aligned physical address of a single 4 KB long page directory.
In computing, protected mode, also called protected virtual address mode, [1] is an operational mode of x86-compatible central processing units (CPUs). It allows system software to use features such as segmentation, virtual memory, paging and safe multi-tasking designed to increase an operating system's control over application software.
"Traditional" 4 KiB paging 4 MiB paging using PSE. Imagine the following scenario: An application program requests a 1 MiB memory block. In order to fulfill this request, an operating system that supports paging and that is running on older x86 CPUs will have to allocate 256 pages of 4 KiB each. An overhead of 1 KiB of memory is required for ...