Q. Under what conditions do page faults occur? Explain the actions taken by the operating system when a page fault occurs.
Answer: A page fault take places when an access to a page that has not been brought into main memory takes place. The operating system authenticates the memory access aborting the program if it is invalid. If it is valid a free frame is located as well as I/O is requested to read the needed page into the free frame. Upon completion of I/O the process table as well as page table are updated and the instruction is restarted.