From 6aedbf986fdb60bb2c44345ec73f19c72e270632 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Tue, 26 Feb 2019 09:49:12 -0800 Subject: [PATCH] tcp: use tcp_md5_needed for timewait sockets This might speedup tcp_twsk_destructor() a bit, avoiding a cache line miss. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/ipv4/tcp_minisocks.c | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-) diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c index 182595e2d40f..79900f783e0d 100644 --- a/net/ipv4/tcp_minisocks.c +++ b/net/ipv4/tcp_minisocks.c @@ -294,12 +294,15 @@ void tcp_time_wait(struct sock *sk, int state, int timeo) * so the timewait ack generating code has the key. */ do { - struct tcp_md5sig_key *key; tcptw->tw_md5_key = NULL; - key = tp->af_specific->md5_lookup(sk, sk); - if (key) { - tcptw->tw_md5_key = kmemdup(key, sizeof(*key), GFP_ATOMIC); - BUG_ON(tcptw->tw_md5_key && !tcp_alloc_md5sig_pool()); + if (static_branch_unlikely(&tcp_md5_needed)) { + struct tcp_md5sig_key *key; + + key = tp->af_specific->md5_lookup(sk, sk); + if (key) { + tcptw->tw_md5_key = kmemdup(key, sizeof(*key), GFP_ATOMIC); + BUG_ON(tcptw->tw_md5_key && !tcp_alloc_md5sig_pool()); + } } } while (0); #endif @@ -338,10 +341,12 @@ EXPORT_SYMBOL(tcp_time_wait); void tcp_twsk_destructor(struct sock *sk) { #ifdef CONFIG_TCP_MD5SIG - struct tcp_timewait_sock *twsk = tcp_twsk(sk); + if (static_branch_unlikely(&tcp_md5_needed)) { + struct tcp_timewait_sock *twsk = tcp_twsk(sk); - if (twsk->tw_md5_key) - kfree_rcu(twsk->tw_md5_key, rcu); + if (twsk->tw_md5_key) + kfree_rcu(twsk->tw_md5_key, rcu); + } #endif } EXPORT_SYMBOL_GPL(tcp_twsk_destructor);