From: Eric Dumazet <edumazet@google.com>
To: "David S . Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
Paolo Abeni <pabeni@redhat.com>
Cc: Simon Horman <horms@kernel.org>,
Neal Cardwell <ncardwell@google.com>,
Kuniyuki Iwashima <kuniyu@google.com>,
netdev@vger.kernel.org, eric.dumazet@gmail.com,
Eric Dumazet <edumazet@google.com>
Subject: [PATCH net-next 3/3] tcp: make tcp_v{4,6}_send_check() static
Date: Tue, 3 Feb 2026 14:40:53 +0000 [thread overview]
Message-ID: <20260203144053.83193-4-edumazet@google.com> (raw)
In-Reply-To: <20260203144053.83193-1-edumazet@google.com>
tcp_v{4,6}_send_check() are only called from tcp_output.c
and should be made static so that the compiler does not need
to put an out of line copy of them.
Remove (struct inet_connection_sock_af_ops) send_check field
and use instead @net_header_len.
Move @net_header_len close to @queue_xmit for data locality
as both are used in TCP tx fast path.
$ scripts/bloat-o-meter -t vmlinux.2 vmlinux.3
add/remove: 0/4 grow/shrink: 0/2 up/down: 0/-320 (-320)
Function old new delta
__tcp_transmit_skb 3075 3072 -3
mptcp_subflow_init 777 763 -14
__pfx_tcp_v6_send_check 16 - -16
__pfx_tcp_v4_send_check 16 - -16
tcp_v6_send_check 135 - -135
tcp_v4_send_check 136 - -136
Total: Before=24893840, After=24893520, chg -0.00%
Signed-off-by: Eric Dumazet <edumazet@google.com>
---
include/net/inet_connection_sock.h | 3 +--
include/net/tcp.h | 3 ---
net/ipv4/tcp_ipv4.c | 1 -
net/ipv4/tcp_output.c | 8 +++-----
net/ipv6/tcp_ipv6.c | 2 --
net/mptcp/subflow.c | 1 -
net/tls/tls_device_fallback.c | 3 ---
7 files changed, 4 insertions(+), 17 deletions(-)
diff --git a/include/net/inet_connection_sock.h b/include/net/inet_connection_sock.h
index ecb362025c4e5183ec78aef4b45c249da87c19ea..bbc9355871c767b51e3d1a4d2436022a8556416c 100644
--- a/include/net/inet_connection_sock.h
+++ b/include/net/inet_connection_sock.h
@@ -34,7 +34,7 @@ struct tcp_congestion_ops;
*/
struct inet_connection_sock_af_ops {
int (*queue_xmit)(struct sock *sk, struct sk_buff *skb, struct flowi *fl);
- void (*send_check)(struct sock *sk, struct sk_buff *skb);
+ u16 net_header_len;
int (*rebuild_header)(struct sock *sk);
void (*sk_rx_dst_set)(struct sock *sk, const struct sk_buff *skb);
int (*conn_request)(struct sock *sk, struct sk_buff *skb);
@@ -43,7 +43,6 @@ struct inet_connection_sock_af_ops {
struct dst_entry *dst,
struct request_sock *req_unhash,
bool *own_req);
- u16 net_header_len;
int (*setsockopt)(struct sock *sk, int level, int optname,
sockptr_t optval, unsigned int optlen);
int (*getsockopt)(struct sock *sk, int level, int optname,
diff --git a/include/net/tcp.h b/include/net/tcp.h
index b9bebf5df4aa6ecf6f421400fb93cefb4104e5aa..339378be8276af2d293f7f52d1aa506e369c5f8d 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -531,7 +531,6 @@ u16 tcp_get_syncookie_mss(struct request_sock_ops *rsk_ops,
* TCP v4 functions exported for the inet6 API
*/
-void tcp_v4_send_check(struct sock *sk, struct sk_buff *skb);
void tcp_v4_mtu_reduced(struct sock *sk);
void tcp_req_err(struct sock *sk, u32 seq, bool abort);
void tcp_ld_RTO_revert(struct sock *sk, u32 seq);
@@ -1124,8 +1123,6 @@ static inline int tcp_v6_sdif(const struct sk_buff *skb)
extern const struct inet_connection_sock_af_ops ipv6_specific;
-void tcp_v6_send_check(struct sock *sk, struct sk_buff *skb);
-
INDIRECT_CALLABLE_DECLARE(int tcp_v6_rcv(struct sk_buff *skb));
void tcp_v6_early_demux(struct sk_buff *skb);
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 7537adf0846f4fe7e0a1dd1cdec559a982329cc1..c7dcacf418380a70d37e3c6005c2202495c74f8e 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -2413,7 +2413,6 @@ EXPORT_IPV6_MOD(inet_sk_rx_dst_set);
const struct inet_connection_sock_af_ops ipv4_specific = {
.queue_xmit = ip_queue_xmit,
- .send_check = tcp_v4_send_check,
.rebuild_header = inet_sk_rebuild_header,
.sk_rx_dst_set = inet_sk_rx_dst_set,
.conn_request = tcp_v4_conn_request,
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 8c1731b544f42cfa1e7629dde128e969b60d2343..7748cee03e87d74b1bf40e60c6458717c6225a36 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -1479,22 +1479,20 @@ INDIRECT_CALLABLE_DECLARE(int ip_queue_xmit(struct sock *sk, struct sk_buff *skb
INDIRECT_CALLABLE_DECLARE(int inet6_csk_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl));
/* This routine computes an IPv4 TCP checksum. */
-void tcp_v4_send_check(struct sock *sk, struct sk_buff *skb)
+static void tcp_v4_send_check(struct sock *sk, struct sk_buff *skb)
{
const struct inet_sock *inet = inet_sk(sk);
__tcp_v4_send_check(skb, inet->inet_saddr, inet->inet_daddr);
}
-EXPORT_IPV6_MOD(tcp_v4_send_check);
#if IS_ENABLED(CONFIG_IPV6)
#include <net/ip6_checksum.h>
-void tcp_v6_send_check(struct sock *sk, struct sk_buff *skb)
+static void tcp_v6_send_check(struct sock *sk, struct sk_buff *skb)
{
__tcp_v6_send_check(skb, &sk->sk_v6_rcv_saddr, &sk->sk_v6_daddr);
}
-EXPORT_IPV6_MOD(tcp_v6_send_check);
#endif
/* This routine actually transmits TCP packets queued in by
@@ -1659,7 +1657,7 @@ static int __tcp_transmit_skb(struct sock *sk, struct sk_buff *skb,
bpf_skops_write_hdr_opt(sk, skb, NULL, NULL, 0, &opts);
#if IS_ENABLED(CONFIG_IPV6)
- if (likely(icsk->icsk_af_ops->send_check == tcp_v6_send_check))
+ if (likely(icsk->icsk_af_ops->net_header_len == sizeof(struct ipv6hdr)))
tcp_v6_send_check(sk, skb);
else
#else
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index ca01b11c0ac959e4ee18dd388c3d17e8a4c88761..11a055f4863a383df5105303cb181e11614b262d 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -2017,7 +2017,6 @@ static struct timewait_sock_ops tcp6_timewait_sock_ops = {
const struct inet_connection_sock_af_ops ipv6_specific = {
.queue_xmit = inet6_csk_xmit,
- .send_check = tcp_v6_send_check,
.rebuild_header = inet6_sk_rebuild_header,
.sk_rx_dst_set = inet6_sk_rx_dst_set,
.conn_request = tcp_v6_conn_request,
@@ -2049,7 +2048,6 @@ static const struct tcp_sock_af_ops tcp_sock_ipv6_specific = {
*/
static const struct inet_connection_sock_af_ops ipv6_mapped = {
.queue_xmit = ip_queue_xmit,
- .send_check = tcp_v4_send_check,
.rebuild_header = inet_sk_rebuild_header,
.sk_rx_dst_set = inet_sk_rx_dst_set,
.conn_request = tcp_v6_conn_request,
diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index 96d54cb2cd93f447e0e04c53d8eaceaa7de3e9c8..e9f91ce43ffc1f5b76f9042a3b20fa34e5b0b453 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -2192,7 +2192,6 @@ void __init mptcp_subflow_init(void)
subflow_v6m_specific = subflow_v6_specific;
subflow_v6m_specific.queue_xmit = ipv4_specific.queue_xmit;
- subflow_v6m_specific.send_check = ipv4_specific.send_check;
subflow_v6m_specific.net_header_len = ipv4_specific.net_header_len;
subflow_v6m_specific.mtu_reduced = ipv4_specific.mtu_reduced;
subflow_v6m_specific.rebuild_header = subflow_rebuild_header;
diff --git a/net/tls/tls_device_fallback.c b/net/tls/tls_device_fallback.c
index 03d508a45aaee9218bb2deed542534785f2019d6..de7d86bdd7ec99df5be4215ff79dbd5e86e49934 100644
--- a/net/tls/tls_device_fallback.c
+++ b/net/tls/tls_device_fallback.c
@@ -149,9 +149,6 @@ static int tls_enc_records(struct aead_request *aead_req,
return rc;
}
-/* Can't use icsk->icsk_af_ops->send_check here because the ip addresses
- * might have been changed by NAT.
- */
static void update_chksum(struct sk_buff *skb, int headln)
{
struct tcphdr *th = tcp_hdr(skb);
--
2.53.0.rc1.225.gd81095ad13-goog
next prev parent reply other threads:[~2026-02-03 14:41 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-02-03 14:40 [PATCH net-next 0/3] tcp: rework tcp_v{4,6}_send_check() Eric Dumazet
2026-02-03 14:40 ` [PATCH net-next 1/3] tcp: inline __tcp_v4_send_check() Eric Dumazet
2026-02-03 14:40 ` [PATCH net-next 2/3] tcp: move tcp_v6_send_check() to tcp_output.c Eric Dumazet
2026-02-09 5:10 ` kernel test robot
2026-02-03 14:40 ` Eric Dumazet [this message]
2026-02-03 17:26 ` [PATCH net-next 3/3] tcp: make tcp_v{4,6}_send_check() static Jakub Kicinski
2026-02-03 18:18 ` Eric Dumazet
2026-02-10 14:09 ` Eric Dumazet
2026-02-03 19:55 ` kernel test robot
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