/* * uvm_map_pageable: sets the pageability of a range in a map. * * => wires map entries. should not be used for transient page locking. * for that, use uvm_fault_wire()/uvm_fault_unwire() (see uvm_vslock()). * => regions specified as not pageable require lock-down (wired) memory * and page tables. * => map must never be read-locked * => if islocked is true, map is already write-locked * => we always unlock the map, since we must downgrade to a read-lock * to call uvm_fault_wire() * => XXXCDC: check this and try and clean it up. */