udp: add a counter into udp_hslot

Adds a counter in udp_hslot to keep an accurate count
of sockets present in chain.

This will permit to upcoming UDP lookup algo to chose
the shortest chain when secondary hash is added.

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 2009-11-08 10:17:05 +00:00 committed by David S. Miller
parent 415ce61aef
commit fdcc8aa953
2 changed files with 11 additions and 0 deletions

View file

@ -50,8 +50,16 @@ struct udp_skb_cb {
};
#define UDP_SKB_CB(__skb) ((struct udp_skb_cb *)((__skb)->cb))
/**
* struct udp_hslot - UDP hash slot
*
* @head: head of list of sockets
* @count: number of sockets in 'head' list
* @lock: spinlock protecting changes to head/count
*/
struct udp_hslot {
struct hlist_nulls_head head;
int count;
spinlock_t lock;
} __attribute__((aligned(2 * sizeof(long))));

View file

@ -218,6 +218,7 @@ found:
sk->sk_hash = snum;
if (sk_unhashed(sk)) {
sk_nulls_add_node_rcu(sk, &hslot->head);
hslot->count++;
sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
}
error = 0;
@ -1053,6 +1054,7 @@ void udp_lib_unhash(struct sock *sk)
spin_lock_bh(&hslot->lock);
if (sk_nulls_del_node_init_rcu(sk)) {
hslot->count--;
inet_sk(sk)->inet_num = 0;
sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
}
@ -1862,6 +1864,7 @@ void __init udp_table_init(struct udp_table *table, const char *name)
}
for (i = 0; i <= table->mask; i++) {
INIT_HLIST_NULLS_HEAD(&table->hash[i].head, i);
table->hash[i].count = 0;
spin_lock_init(&table->hash[i].lock);
}
}