What is page fault explain?

In computing, a page fault (sometimes called PF or hard fault) is an exception that the memory management unit (MMU) raises when a process accesses a memory page without proper preparations. Besides, the actual page contents may need to be loaded from a backing store, such as a disk.

What happens on a page fault?

A page fault occurs when a program attempts to access a block of memory that is not stored in the physical memory, or RAM. The fault notifies the operating system that it must locate the data in virtual memory, then transfer it from the storage device, such as an HDD or SSD, to the system RAM.

What is page fault example?

For example, if we consider reference string 3, 2, 1, 0, 3, 2, 4, 3, 2, 1, 0, 4 and 3 slots, we get 9 total page faults, but if we increase slots to 4, we get 10 page faults. In this algorithm, pages are replaced which would not be used for the longest duration of time in the future.

What can cause a page fault?

Page faults are generated when an application tries to use memory that is part of its working set, but can’t find it. Page faults can be either hard or soft: Hard page faults occur when the page is found in the page file on the hard disk. Soft page faults happen when the page is found somewhere else in memory.

Are page faults bad?

Page Faults are a very normal part of the OS behavior. This is especially true for Windows environments where Page Faulting will be very common. Linux-based OSes will also Page Fault, but at a much lower rate by design. As a rule, Windows OSes will Page Fault frequently and it’s normal.

How do I get rid of page faults?

In general, having a smaller memory footprint, and having things that will often be accessed around the same time be on the same page will decrease the number of page faults.

What causes page fault nonpaged area?

The PAGE FAULT IN NONPAGED AREA stop code can have many causes. In most cases, when a program or the OS references a specific memory page, if it’s not resident in RAM, the page manager throws a “page fault” (page not present) status. Ultimately, this means the requested page gets read from the page file.