From 723b46108f8ee75b61ce703d0c9225e4f537bc46 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Tue, 25 Nov 2008 13:55:15 -0800 Subject: net: udp_unhash() can test if sk is hashed Impact: Optimization Like done in inet_unhash(), we can avoid taking a chain lock if socket is not hashed in udp_unhash() Triggered by close(socket(AF_INET, SOCK_DGRAM, 0)); Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/ipv4/udp.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) (limited to 'net/ipv4/udp.c') diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index 549114472db3..cf5ab0581eba 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -970,16 +970,18 @@ int udp_disconnect(struct sock *sk, int flags) void udp_lib_unhash(struct sock *sk) { - struct udp_table *udptable = sk->sk_prot->h.udp_table; - unsigned int hash = udp_hashfn(sock_net(sk), sk->sk_hash); - struct udp_hslot *hslot = &udptable->hash[hash]; + if (sk_hashed(sk)) { + struct udp_table *udptable = sk->sk_prot->h.udp_table; + unsigned int hash = udp_hashfn(sock_net(sk), sk->sk_hash); + struct udp_hslot *hslot = &udptable->hash[hash]; - spin_lock_bh(&hslot->lock); - if (sk_nulls_del_node_init_rcu(sk)) { - inet_sk(sk)->num = 0; - sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); + spin_lock_bh(&hslot->lock); + if (sk_nulls_del_node_init_rcu(sk)) { + inet_sk(sk)->num = 0; + sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); + } + spin_unlock_bh(&hslot->lock); } - spin_unlock_bh(&hslot->lock); } EXPORT_SYMBOL(udp_lib_unhash); -- cgit v1.2.3