From 5bb4c45d466cb28dd0a7f15f80c4cb7768054e94 Mon Sep 17 00:00:00 2001 From: Jakub Sitnicki Date: Tue, 17 Mar 2020 18:04:38 +0100 Subject: [PATCH] net/tls: Read sk_prot once when building tls proto ops Apart from being a "tremendous" win when it comes to generated machine code (see bloat-o-meter output for x86-64 below) this mainly prepares ground for annotating access to sk_prot with READ_ONCE, so that we don't pepper the code with access annotations and needlessly repeat loads. add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-46 (-46) Function old new delta tls_init 851 805 -46 Total: Before=21063, After=21017, chg -0.22% Signed-off-by: Jakub Sitnicki Signed-off-by: David S. Miller --- net/tls/tls_main.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) diff --git a/net/tls/tls_main.c b/net/tls/tls_main.c index ff08b2ff7597..e7de0306a7df 100644 --- a/net/tls/tls_main.c +++ b/net/tls/tls_main.c @@ -628,24 +628,25 @@ struct tls_context *tls_ctx_create(struct sock *sk) static void tls_build_proto(struct sock *sk) { int ip_ver = sk->sk_family == AF_INET6 ? TLSV6 : TLSV4; + const struct proto *prot = sk->sk_prot; /* Build IPv6 TLS whenever the address of tcpv6 _prot changes */ if (ip_ver == TLSV6 && - unlikely(sk->sk_prot != smp_load_acquire(&saved_tcpv6_prot))) { + unlikely(prot != smp_load_acquire(&saved_tcpv6_prot))) { mutex_lock(&tcpv6_prot_mutex); - if (likely(sk->sk_prot != saved_tcpv6_prot)) { - build_protos(tls_prots[TLSV6], sk->sk_prot); - smp_store_release(&saved_tcpv6_prot, sk->sk_prot); + if (likely(prot != saved_tcpv6_prot)) { + build_protos(tls_prots[TLSV6], prot); + smp_store_release(&saved_tcpv6_prot, prot); } mutex_unlock(&tcpv6_prot_mutex); } if (ip_ver == TLSV4 && - unlikely(sk->sk_prot != smp_load_acquire(&saved_tcpv4_prot))) { + unlikely(prot != smp_load_acquire(&saved_tcpv4_prot))) { mutex_lock(&tcpv4_prot_mutex); - if (likely(sk->sk_prot != saved_tcpv4_prot)) { - build_protos(tls_prots[TLSV4], sk->sk_prot); - smp_store_release(&saved_tcpv4_prot, sk->sk_prot); + if (likely(prot != saved_tcpv4_prot)) { + build_protos(tls_prots[TLSV4], prot); + smp_store_release(&saved_tcpv4_prot, prot); } mutex_unlock(&tcpv4_prot_mutex); } -- 2.20.1