UVM_PAGE_ARRAY_FILL_DENSE
const bool dense = (flags & UVM_PAGE_ARRAY_FILL_DENSE) != 0;
(UVM_PAGE_ARRAY_FILL_DIRTY|UVM_PAGE_ARRAY_FILL_DENSE) : 0);
if ((a->ar_flags & UVM_PAGE_ARRAY_FILL_DENSE) != 0) {
KASSERT((a->ar_flags & UVM_PAGE_ARRAY_FILL_DENSE) == 0);