What do you mean by page fault

Question

What do you mean by page fault? Explain it with proper description?

Answer 1

If the ‘present bit’ is a set in the translation look aside buffer which is a high speed cache, then the page is in the memory and the processor can retrieve the frame number from the page table entry from real address. The processor as well updates the translation look aside buffer (TLB) to comprise this new page table entry. Lastly, if the present bit is not set, then the desired page is not in memory and a memory access fault, termed as the page fault, is issued. At this point we leave the field of realm or activity of the hardware and invoke the operating system, which loads the required page and updates the page table.