This one is not that big, but is widely used: saves 1200 bytes
from net/ipv4/built-in.o

add/remove: 1/0 grow/shrink: 1/12 up/down: 97/-1300 (-1203)
function                                     old     new   delta
inet_twsk_put                                  -      87     +87
__inet_lookup_listener                       274     284     +10
tcp_sacktag_write_queue                     2255    2254      -1
tcp_time_wait                                482     411     -71
__inet_check_established                     796     722     -74
tcp_v4_err                                   973     898     -75
__inet_twsk_kill                             230     154     -76
inet_twsk_deschedule                         180     103     -77
tcp_v4_do_rcv                                462     384     -78
inet_hash_connect                            686     607     -79
inet_twdr_do_twkill_work                     236     150     -86
inet_twdr_twcal_tick                         395     307     -88
tcp_v4_rcv                                  1744    1480    -264
tcp_timewait_state_process                   975     644    -331

Export it for ipv6 module.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>