Search results
Results from the WOW.Com Content Network
PageDefrag is a program, developed by Sysinternals (now distributed by Microsoft), for Microsoft Windows that runs at start-up to defragment the virtual memory page file, the registry files and the Event Viewer's logs (files such as AppEvent.Evt, SysEvent.Evt, SecEvent.Evt and so on).
The Windows Task Manager utility for Windows XP and Server 2003, in its Performance tab, shows three counters related to commit charge: . Total is the amount of pagefile-backed virtual address space in use, i.e., the current commit charge.
A null pointer is usually represented as a pointer to address 0 in the address space; many operating systems set up the MMU to indicate that the page that contains that address is not in memory, and do not include that page in the virtual address space, so that attempts to read or write the memory referenced by a null pointer get an invalid ...
A page, memory page, or virtual page is a fixed-length contiguous block of virtual memory, described by a single entry in a page table.It is the smallest unit of data for memory management in an operating system that uses virtual memory.
However, the page file only expands when it has been filled, which, in its default configuration, is 150% of the total amount of physical memory. [16] Thus the total demand for page file-backed virtual memory must exceed 250% of the computer's physical memory before the page file will expand.
Pages in the page cache modified after being brought in are called dirty pages. [5] Since non-dirty pages in the page cache have identical copies in secondary storage (e.g. hard disk drive or solid-state drive), discarding and reusing their space is much quicker than paging out application memory, and is often preferred over flushing the dirty pages into secondary storage and reusing their space.
In computer operating systems, demand paging (as opposed to anticipatory paging) is a method of virtual memory management. In a system that uses demand paging, the operating system copies a disk page into physical memory only when an attempt is made to access it and that page is not already in memory (i.e., if a page fault occurs).
Virtual memory combines active RAM and inactive memory on DASD [a] to form a large range of contiguous addresses.. In computing, virtual memory, or virtual storage, [b] is a memory management technique that provides an "idealized abstraction of the storage resources that are actually available on a given machine" [3] which "creates the illusion to users of a very large (main) memory".