4be14af9cf
being that PHYS_TO_VM_PAGE() returns the wrong vm_page for fictitious pages but unwiring uses PHYS_TO_VM_PAGE(). The resulting panic reported an unexpected wired count. Rather than attempting to fix PHYS_TO_VM_PAGE(), this fix takes advantage of the properties of fictitious pages. Specifically, fictitious pages will never be completely unwired. Therefore, we can keep a fictitious page's wired count forever set to one and thereby avoid the use of PHYS_TO_VM_PAGE() when we know that we're working with a fictitious page, just not which one. In collaboration with: green@, tegge@ PR: kern/29915