am_small
chunkp = &amapp->am_small;
amap_wiperange_chunk(amap, &amap->am_small, slotoff, slots);
return &amap->am_small;
size = offsetof(struct vm_amap, am_small.ac_anon) +
amap->am_small.ac_nslot = slots;
&(amap)->am_small : TAILQ_FIRST(&(amap)->am_chunks)); \