ULONG
MiDoesPdeExist64(
  IN  PMMPTE PointerPde
  );

Routine Description:

    This routine examines the specified Page Directory Entry to determine
    if the page table page mapped by the PDE exists.

    If the page table page exists and is not currently in memory, the
    working set mutex and, if held, the PFN mutex are released and the
    page table page is faulted into the working set.  The mutexes are
    required.

    If the PDE exists, the function returns true.

Arguments:

    PointerPde - Supplies a pointer to the PDE to examine and potentially
                 bring into the working set.

    TargetProcess - Supplies a pointer to the current process.

    PfnMutexHeld - Supplies the value TRUE if the PFN mutex is held, FALSE
                   otherwise.

Return Value:

    TRUE if the PDE exists, FALSE if the PDE is zero.

Environment:

    Kernel mode, APCs disabled, WorkingSetLock held.