From b1e014a1f3275a6f3d0f2b30b8117447fc3915f5 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Tue, 28 Oct 2025 12:58:01 +0100 Subject: [PATCH] tcp: add newval parameter to tcp_rcvbuf_grow() This patch has no functional change, and prepares the following one. tcp_rcvbuf_grow() will need to have access to tp->rcvq_space.space old and new values. Change mptcp_rcvbuf_grow() in a similar way. Signed-off-by: Eric Dumazet [ Moved 'oldval' declaration to the next patch to avoid warnings at build time. ] Signed-off-by: Matthieu Baerts (NGI0) Reviewed-by: Neal Cardwell Link: https://patch.msgid.link/20251028-net-tcp-recv-autotune-v3-3-74b43ba4c84c@kernel.org Signed-off-by: Jakub Kicinski --- include/net/tcp.h | 2 +- net/ipv4/tcp_input.c | 14 +++++++------- net/mptcp/protocol.c | 20 ++++++++------------ 3 files changed, 16 insertions(+), 20 deletions(-) diff --git a/include/net/tcp.h b/include/net/tcp.h index 5ca230ed526a..ab20f549b8f9 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -370,7 +370,7 @@ void tcp_delack_timer_handler(struct sock *sk); int tcp_ioctl(struct sock *sk, int cmd, int *karg); enum skb_drop_reason tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb); void tcp_rcv_established(struct sock *sk, struct sk_buff *skb); -void tcp_rcvbuf_grow(struct sock *sk); +void tcp_rcvbuf_grow(struct sock *sk, u32 newval); void tcp_rcv_space_adjust(struct sock *sk); int tcp_twsk_unique(struct sock *sk, struct sock *sktw, void *twp); void tcp_twsk_destructor(struct sock *sk); diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 31ea5af49f2d..cb4e07f84ae2 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -891,18 +891,20 @@ static inline void tcp_rcv_rtt_measure_ts(struct sock *sk, } } -void tcp_rcvbuf_grow(struct sock *sk) +void tcp_rcvbuf_grow(struct sock *sk, u32 newval) { const struct net *net = sock_net(sk); struct tcp_sock *tp = tcp_sk(sk); - int rcvwin, rcvbuf, cap; + u32 rcvwin, rcvbuf, cap; + + tp->rcvq_space.space = newval; if (!READ_ONCE(net->ipv4.sysctl_tcp_moderate_rcvbuf) || (sk->sk_userlocks & SOCK_RCVBUF_LOCK)) return; /* slow start: allow the sender to double its rate. */ - rcvwin = tp->rcvq_space.space << 1; + rcvwin = newval << 1; if (!RB_EMPTY_ROOT(&tp->out_of_order_queue)) rcvwin += TCP_SKB_CB(tp->ooo_last_skb)->end_seq - tp->rcv_nxt; @@ -943,9 +945,7 @@ void tcp_rcv_space_adjust(struct sock *sk) trace_tcp_rcvbuf_grow(sk, time); - tp->rcvq_space.space = copied; - - tcp_rcvbuf_grow(sk); + tcp_rcvbuf_grow(sk, copied); new_measure: tp->rcvq_space.seq = tp->copied_seq; @@ -5270,7 +5270,7 @@ end: } /* do not grow rcvbuf for not-yet-accepted or orphaned sockets. */ if (sk->sk_socket) - tcp_rcvbuf_grow(sk); + tcp_rcvbuf_grow(sk, tp->rcvq_space.space); } static int __must_check tcp_queue_rcv(struct sock *sk, struct sk_buff *skb, diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index a8a3bdf95543..052a0c62023f 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -194,17 +194,18 @@ static bool mptcp_ooo_try_coalesce(struct mptcp_sock *msk, struct sk_buff *to, * - mptcp does not maintain a msk-level window clamp * - returns true when the receive buffer is actually updated */ -static bool mptcp_rcvbuf_grow(struct sock *sk) +static bool mptcp_rcvbuf_grow(struct sock *sk, u32 newval) { struct mptcp_sock *msk = mptcp_sk(sk); const struct net *net = sock_net(sk); - int rcvwin, rcvbuf, cap; + u32 rcvwin, rcvbuf, cap; + msk->rcvq_space.space = newval; if (!READ_ONCE(net->ipv4.sysctl_tcp_moderate_rcvbuf) || (sk->sk_userlocks & SOCK_RCVBUF_LOCK)) return false; - rcvwin = msk->rcvq_space.space << 1; + rcvwin = newval << 1; if (!RB_EMPTY_ROOT(&msk->out_of_order_queue)) rcvwin += MPTCP_SKB_CB(msk->ooo_last_skb)->end_seq - msk->ack_seq; @@ -334,7 +335,7 @@ end: skb_set_owner_r(skb, sk); /* do not grow rcvbuf for not-yet-accepted or orphaned sockets. */ if (sk->sk_socket) - mptcp_rcvbuf_grow(sk); + mptcp_rcvbuf_grow(sk, msk->rcvq_space.space); } static void mptcp_init_skb(struct sock *ssk, struct sk_buff *skb, int offset, @@ -2049,10 +2050,7 @@ static void mptcp_rcv_space_adjust(struct mptcp_sock *msk, int copied) if (msk->rcvq_space.copied <= msk->rcvq_space.space) goto new_measure; - msk->rcvq_space.space = msk->rcvq_space.copied; - if (mptcp_rcvbuf_grow(sk)) { - int copied = msk->rcvq_space.copied; - + if (mptcp_rcvbuf_grow(sk, msk->rcvq_space.copied)) { /* Make subflows follow along. If we do not do this, we * get drops at subflow level if skbs can't be moved to * the mptcp rx queue fast enough (announced rcv_win can @@ -2065,10 +2063,8 @@ static void mptcp_rcv_space_adjust(struct mptcp_sock *msk, int copied) ssk = mptcp_subflow_tcp_sock(subflow); slow = lock_sock_fast(ssk); /* subflows can be added before tcp_init_transfer() */ - if (tcp_sk(ssk)->rcvq_space.space) { - tcp_sk(ssk)->rcvq_space.space = copied; - tcp_rcvbuf_grow(ssk); - } + if (tcp_sk(ssk)->rcvq_space.space) + tcp_rcvbuf_grow(ssk, msk->rcvq_space.copied); unlock_sock_fast(ssk, slow); } } -- 2.47.3