From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: [PATCH net-next] tcp: md5: only call tp->af_specific->md5_lookup() for md5 sockets Date: Mon, 23 Apr 2018 14:46:25 -0700 Message-ID: <20180423214625.107867-1-edumazet@google.com> Cc: netdev , Eric Dumazet , Eric Dumazet To: "David S . Miller" Return-path: Received: from mail-pg0-f68.google.com ([74.125.83.68]:43144 "EHLO mail-pg0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932291AbeDWVqb (ORCPT ); Mon, 23 Apr 2018 17:46:31 -0400 Received: by mail-pg0-f68.google.com with SMTP id f132so9274254pgc.10 for ; Mon, 23 Apr 2018 14:46:31 -0700 (PDT) Sender: netdev-owner@vger.kernel.org List-ID: RETPOLINE made calls to tp->af_specific->md5_lookup() quite expensive, given they have no result. We can omit the calls for sockets that have no md5 keys. Signed-off-by: Eric Dumazet --- net/ipv4/tcp_output.c | 26 ++++++++++++++------------ 1 file changed, 14 insertions(+), 12 deletions(-) diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 383cac0ff0ec059ca7dbc1a6304cc7f8183e008d..95feffb6d53f8a9eadfb15a2fffeec498d6e993a 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -585,14 +585,15 @@ static unsigned int tcp_syn_options(struct sock *sk, struct sk_buff *skb, unsigned int remaining = MAX_TCP_OPTION_SPACE; struct tcp_fastopen_request *fastopen = tp->fastopen_req; + *md5 = NULL; #ifdef CONFIG_TCP_MD5SIG - *md5 = tp->af_specific->md5_lookup(sk, sk); - if (*md5) { - opts->options |= OPTION_MD5; - remaining -= TCPOLEN_MD5SIG_ALIGNED; + if (unlikely(rcu_access_pointer(tp->md5sig_info))) { + *md5 = tp->af_specific->md5_lookup(sk, sk); + if (*md5) { + opts->options |= OPTION_MD5; + remaining -= TCPOLEN_MD5SIG_ALIGNED; + } } -#else - *md5 = NULL; #endif /* We always get an MSS option. The option bytes which will be seen in @@ -720,14 +721,15 @@ static unsigned int tcp_established_options(struct sock *sk, struct sk_buff *skb opts->options = 0; + *md5 = NULL; #ifdef CONFIG_TCP_MD5SIG - *md5 = tp->af_specific->md5_lookup(sk, sk); - if (unlikely(*md5)) { - opts->options |= OPTION_MD5; - size += TCPOLEN_MD5SIG_ALIGNED; + if (unlikely(rcu_access_pointer(tp->md5sig_info))) { + *md5 = tp->af_specific->md5_lookup(sk, sk); + if (*md5) { + opts->options |= OPTION_MD5; + size += TCPOLEN_MD5SIG_ALIGNED; + } } -#else - *md5 = NULL; #endif if (likely(tp->rx_opt.tstamp_ok)) { -- 2.17.0.484.g0c8726318c-goog