AMAP_REFALL
amap_adjref_anons(amap, offset, len, 1, (flags & AMAP_REFALL) != 0);
uvm_unmap_detach(&dead_entries, AMAP_REFALL);
flags & AMAP_REFALL);
entry, &dead, flags, AMAP_SHARED | AMAP_REFALL);
uvm_unmap_detach(&dead_entries, AMAP_REFALL);