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authorEric Dumazet <edumazet@google.com>2012-12-05 10:18:10 +0100
committerDavid S. Miller <davem@davemloft.net>2012-12-05 22:01:28 +0100
commit0e1efe9d5e10921f1e2152b108e013605fca3c9f (patch)
treec254570a9058345ea2eb1f319cc5c88cfe8c65ee /net/ipv6/anycast.c
parentnet: doc: add default value for neighbour parameters (diff)
downloadlinux-0e1efe9d5e10921f1e2152b108e013605fca3c9f.tar.xz
linux-0e1efe9d5e10921f1e2152b108e013605fca3c9f.zip
ipv6: avoid taking locks at socket dismantle
ipv6_sock_mc_close() is called for ipv6 sockets at close time, and most of them don't use multicast. Add a test to avoid contention on a shared spinlock. Same heuristic applies for ipv6_sock_ac_close(), to avoid contention on a shared rwlock. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv6/anycast.c')
-rw-r--r--net/ipv6/anycast.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/net/ipv6/anycast.c b/net/ipv6/anycast.c
index 2f4f584d796d..757a810d8f15 100644
--- a/net/ipv6/anycast.c
+++ b/net/ipv6/anycast.c
@@ -189,6 +189,9 @@ void ipv6_sock_ac_close(struct sock *sk)
struct net *net = sock_net(sk);
int prev_index;
+ if (!np->ipv6_ac_list)
+ return;
+
write_lock_bh(&ipv6_sk_ac_lock);
pac = np->ipv6_ac_list;
np->ipv6_ac_list = NULL;