swap_getconpage
int swap_getconpage(struct vnode *vp, u_offset_t off, size_t len,
extern int swap_getconpage(struct vnode *, u_offset_t, size_t,
err = swap_getconpage(vp, (u_offset_t)off, PAGESIZE,
err = swap_getconpage(vp, (u_offset_t)off, PAGESIZE, NULL, pl,
err = swap_getconpage(ap_vp, ap_off, PAGESIZE,