Paging: Difference between revisions

A page fault exception is caused when a process is seeking to access an area of virtual memory that is not mapped to any physical memory, when a write is attempted on a read-only page, when accessing a PTE or PDE with the reserved bit or when permissions are inadequate. A page fault can either be pure, which occurs when the faulting process has permission to access the page, or invalid, which is due to a protection violation. Pure page faults aren't errors, but are resolved through the page fault handler by performing the appropriate map operation and/or page swap.