diff options
| author |   Eric Dumazet <edumazet@google.com> | 2018-11-27 15:03:21 -0800 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2018-11-30 13:28:03 -0800 |
| commit | 6015c71e656bb6895b416c31a8b7db457e45cecf (patch) | |
| tree | ba31e8ae21f52048e475daa33f6bb86df5bfc3b5 /net/ipv4 | |
| parent | Merge branch 'tcp-take-a-bit-more-care-of-backlog-stress' (diff) | |
| download | linux-dev-6015c71e656bb6895b416c31a8b7db457e45cecf.tar.xz linux-dev-6015c71e656bb6895b416c31a8b7db457e45cecf.zip | |
tcp: md5: add tcp_md5_needed jump label
Most linux hosts never setup TCP MD5 keys. We can avoid a
cache line miss (accessing tp->md5ig_info) on RX and TX
using a jump label.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4')
| -rw-r--r-- | net/ipv4/tcp.c | 5 | ||||
| -rw-r--r-- | net/ipv4/tcp_ipv4.c | 11 | ||||
| -rw-r--r-- | net/ipv4/tcp_output.c | 6 |
3 files changed, 15 insertions, 7 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 252048776dbb..215e4d3b3616 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -3656,8 +3656,11 @@ bool tcp_alloc_md5sig_pool(void) if (unlikely(!tcp_md5sig_pool_populated)) { mutex_lock(&tcp_md5sig_mutex); - if (!tcp_md5sig_pool_populated) + if (!tcp_md5sig_pool_populated) { __tcp_alloc_md5sig_pool(); + if (tcp_md5sig_pool_populated) + static_key_slow_inc(&tcp_md5_needed); + } mutex_unlock(&tcp_md5sig_mutex); } diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 4904250a9aac..efc6fef692ff 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -970,10 +970,13 @@ static void tcp_v4_reqsk_destructor(struct request_sock *req) * We need to maintain these in the sk structure. */ +struct static_key tcp_md5_needed __read_mostly; +EXPORT_SYMBOL(tcp_md5_needed); + /* Find the Key structure for an address. */ -struct tcp_md5sig_key *tcp_md5_do_lookup(const struct sock *sk, - const union tcp_md5_addr *addr, - int family) +struct tcp_md5sig_key *__tcp_md5_do_lookup(const struct sock *sk, + const union tcp_md5_addr *addr, + int family) { const struct tcp_sock *tp = tcp_sk(sk); struct tcp_md5sig_key *key; @@ -1011,7 +1014,7 @@ struct tcp_md5sig_key *tcp_md5_do_lookup(const struct sock *sk, } return best_match; } -EXPORT_SYMBOL(tcp_md5_do_lookup); +EXPORT_SYMBOL(__tcp_md5_do_lookup); static struct tcp_md5sig_key *tcp_md5_do_lookup_exact(const struct sock *sk, const union tcp_md5_addr *addr, diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index e4c1e51b18c1..d3b691f3a9e8 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -594,7 +594,8 @@ static unsigned int tcp_syn_options(struct sock *sk, struct sk_buff *skb, *md5 = NULL; #ifdef CONFIG_TCP_MD5SIG - if (unlikely(rcu_access_pointer(tp->md5sig_info))) { + if (static_key_false(&tcp_md5_needed) && + rcu_access_pointer(tp->md5sig_info)) { *md5 = tp->af_specific->md5_lookup(sk, sk); if (*md5) { opts->options |= OPTION_MD5; @@ -730,7 +731,8 @@ static unsigned int tcp_established_options(struct sock *sk, struct sk_buff *skb *md5 = NULL; #ifdef CONFIG_TCP_MD5SIG - if (unlikely(rcu_access_pointer(tp->md5sig_info))) { + if (static_key_false(&tcp_md5_needed) && + rcu_access_pointer(tp->md5sig_info)) { *md5 = tp->af_specific->md5_lookup(sk, sk); if (*md5) { opts->options |= OPTION_MD5; |