udp: bind() optimisation

UDP bind() can be O(N^2) in some pathological cases.

Thanks to secondary hash tables, we can make it O(N)

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet
2009-11-09 05:26:33 +00:00
committed by David S. Miller
parent 0ab365f463
commit 30fff9231f
4 changed files with 80 additions and 16 deletions

View File

@@ -100,12 +100,14 @@ static unsigned int udp6_portaddr_hash(struct net *net,
int udp_v6_get_port(struct sock *sk, unsigned short snum)
{
unsigned int hash2_nulladdr =
udp6_portaddr_hash(sock_net(sk), &in6addr_any, snum);
unsigned int hash2_partial =
udp6_portaddr_hash(sock_net(sk), &inet6_sk(sk)->rcv_saddr, 0);
/* precompute partial secondary hash */
udp_sk(sk)->udp_portaddr_hash =
udp6_portaddr_hash(sock_net(sk),
&inet6_sk(sk)->rcv_saddr,
0);
return udp_lib_get_port(sk, snum, ipv6_rcv_saddr_equal);
udp_sk(sk)->udp_portaddr_hash = hash2_partial;
return udp_lib_get_port(sk, snum, ipv6_rcv_saddr_equal, hash2_nulladdr);
}
static inline int compute_score(struct sock *sk, struct net *net,
@@ -181,8 +183,6 @@ static inline int compute_score2(struct sock *sk, struct net *net,
return score;
}
#define udp_portaddr_for_each_entry_rcu(__sk, node, list) \
hlist_nulls_for_each_entry_rcu(__sk, node, list, __sk_common.skc_portaddr_node)
/* called with read_rcu_lock() */
static struct sock *udp6_lib_lookup2(struct net *net,