r308569: Always call PHYS_TO_VM_PAGE() in is_managed(). Fast road for addresses under first_page cannot be taken as this variable is connected only to vm_page_array segment. There could be more segments in system like the ones for various fictitious page ranges. These can be situated under vm_page_array segment and so, they could be skipped before this fix. However, as far as I know, there is no report associated with it. r308570: The return type of is_managed() was changed from boolean_t to bool type in r308569. Now, propagate this change further for consistency sake.