net: listening_hash get a spinlock per bucket
This patch prepares RCU migration of listening_hash table for
TCP/DCCP protocols.
listening_hash table being small (32 slots per protocol), we add
a spinlock for each slot, instead of a single rwlock for whole table.
This should reduce hold time of readers, and writers concurrency.
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/inet6_hashtables.c b/net/ipv6/inet6_hashtables.c
index c1b4d40..21544b9 100644
--- a/net/ipv6/inet6_hashtables.c
+++ b/net/ipv6/inet6_hashtables.c
@@ -25,30 +25,30 @@
void __inet6_hash(struct sock *sk)
{
struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
- rwlock_t *lock;
WARN_ON(!sk_unhashed(sk));
if (sk->sk_state == TCP_LISTEN) {
- struct hlist_head *list;
+ struct inet_listen_hashbucket *ilb;
- list = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)];
- lock = &hashinfo->lhash_lock;
- inet_listen_wlock(hashinfo);
- __sk_add_node(sk, list);
+ ilb = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)];
+ spin_lock(&ilb->lock);
+ __sk_add_node(sk, &ilb->head);
+ spin_unlock(&ilb->lock);
} else {
unsigned int hash;
struct hlist_nulls_head *list;
+ rwlock_t *lock;
sk->sk_hash = hash = inet6_sk_ehashfn(sk);
list = &inet_ehash_bucket(hashinfo, hash)->chain;
lock = inet_ehash_lockp(hashinfo, hash);
write_lock(lock);
__sk_nulls_add_node_rcu(sk, list);
+ write_unlock(lock);
}
sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
- write_unlock(lock);
}
EXPORT_SYMBOL(__inet6_hash);
@@ -126,10 +126,11 @@
const struct hlist_node *node;
struct sock *result = NULL;
int score, hiscore = 0;
+ struct inet_listen_hashbucket *ilb;
- read_lock(&hashinfo->lhash_lock);
- sk_for_each(sk, node,
- &hashinfo->listening_hash[inet_lhashfn(net, hnum)]) {
+ ilb = &hashinfo->listening_hash[inet_lhashfn(net, hnum)];
+ spin_lock(&ilb->lock);
+ sk_for_each(sk, node, &ilb->head) {
if (net_eq(sock_net(sk), net) && inet_sk(sk)->num == hnum &&
sk->sk_family == PF_INET6) {
const struct ipv6_pinfo *np = inet6_sk(sk);
@@ -157,7 +158,7 @@
}
if (result)
sock_hold(result);
- read_unlock(&hashinfo->lhash_lock);
+ spin_unlock(&ilb->lock);
return result;
}