Contents
What is the procedure for handling the page fault?
5.4. 3.1. Handling of a Page Fault
- Check the location of the referenced page in the PMT.
- If a page fault occured, call on the operating system to fix it.
- Using the frame replacement algorithm, find the frame location.
- Read the data from disk to memory.
- Update the page map table for the process.
What happens when a page fault occurs?
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.
When page fault occurs and how it is handled?
When handling a page fault, the operating system tries to make the required page accessible at the location in physical memory or terminates the program in cases of an illegal memory access.
What is swapped out when page faults occur?
The process of writing pages out to disk to free memory is called swapping-out. If later a page fault is raised because the page is on disk, in the swap area rather than in memory, then the kernel will read back in the page from the disk and satisfy the page fault. This is swapping-in.
Does a page fault cause a mode switch?
The page fault can be occured in user mode or kernel mode. If it’s occured in user mode, regardless of the result, resulting in a context switch.
What is page fault time?
Page fault service time (if nothing specific is given ) includes time taken to access secondary memory to find the page + time taken to access the main memory after the page is loaded.
What causes 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.