uao_dropswap
uao_dropswap(&aobj->u_obj, pageidx);
uao_dropswap(&aobj->u_obj, pg->offset >> PAGE_SHIFT);
uao_dropswap(uobj, pg->offset >> PAGE_SHIFT);
int uao_dropswap(struct uvm_object *, int);
uao_dropswap(uobj, pg->offset >> PAGE_SHIFT);
slot = uao_dropswap(uobj, curoff >> PAGE_SHIFT);
uao_dropswap(uobj, i);
slot = uao_dropswap(pg->uobject, pg->offset >> PAGE_SHIFT);