From 6f459eda8b60382efa0da2ca025c26a2018adc87 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Tue, 10 Mar 2026 12:44:51 +0000 Subject: tcp: add tcp_release_cb_cond() helper Majority of tcp_release_cb() calls do nothing at all. Provide tcp_release_cb_cond() helper so that release_sock() can avoid these calls. Also hint the compiler that __release_sock() and wake_up() are rarely called. $ scripts/bloat-o-meter -t vmlinux.old vmlinux.new add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-77 (-77) Function old new delta release_sock 258 181 -77 Total: Before=25235790, After=25235713, chg -0.00% Signed-off-by: Eric Dumazet Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20260310124451.2280968-1-edumazet@google.com Signed-off-by: Paolo Abeni --- include/linux/tcp.h | 7 +++++++ include/net/tcp.h | 14 ++++++++++++++ 2 files changed, 21 insertions(+) (limited to 'include') diff --git a/include/linux/tcp.h b/include/linux/tcp.h index c44cf9ae8d16..bcebc4f07532 100644 --- a/include/linux/tcp.h +++ b/include/linux/tcp.h @@ -548,6 +548,13 @@ enum tsq_flags { TCPF_ACK_DEFERRED = BIT(TCP_ACK_DEFERRED), }; +/* Flags of interest for tcp_release_cb() */ +#define TCP_DEFERRED_ALL (TCPF_TSQ_DEFERRED | \ + TCPF_WRITE_TIMER_DEFERRED | \ + TCPF_DELACK_TIMER_DEFERRED | \ + TCPF_MTU_REDUCED_DEFERRED | \ + TCPF_ACK_DEFERRED) + #define tcp_sk(ptr) container_of_const(ptr, struct tcp_sock, inet_conn.icsk_inet.sk) /* Variant of tcp_sk() upgrading a const sock to a read/write tcp socket. diff --git a/include/net/tcp.h b/include/net/tcp.h index 9f0aee9e5d76..48dffcca0a71 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -375,7 +375,21 @@ int tcp_send_mss(struct sock *sk, int *size_goal, int flags); int tcp_wmem_schedule(struct sock *sk, int copy); void tcp_push(struct sock *sk, int flags, int mss_now, int nonagle, int size_goal); + void tcp_release_cb(struct sock *sk); + +static inline bool tcp_release_cb_cond(struct sock *sk) +{ +#ifdef CONFIG_INET + if (likely(sk->sk_prot->release_cb == tcp_release_cb)) { + if (unlikely(smp_load_acquire(&sk->sk_tsq_flags) & TCP_DEFERRED_ALL)) + tcp_release_cb(sk); + return true; + } +#endif + return false; +} + void tcp_wfree(struct sk_buff *skb); void tcp_write_timer_handler(struct sock *sk); void tcp_delack_timer_handler(struct sock *sk); -- cgit v1.2.3