diff --git a/include/net/tcp.h b/include/net/tcp.h index cce285f70c8e..7cf1b4972c66 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -1401,6 +1401,19 @@ static inline int tcp_full_space(const struct sock *sk) return tcp_win_from_space(sk, READ_ONCE(sk->sk_rcvbuf)); } +/* We provision sk_rcvbuf around 200% of sk_rcvlowat. + * If 87.5 % (7/8) of the space has been consumed, we want to override + * SO_RCVLOWAT constraint, since we are receiving skbs with too small + * len/truesize ratio. + */ +static inline bool tcp_rmem_pressure(const struct sock *sk) +{ + int rcvbuf = READ_ONCE(sk->sk_rcvbuf); + int threshold = rcvbuf - (rcvbuf >> 3); + + return atomic_read(&sk->sk_rmem_alloc) > threshold; +} + extern void tcp_openreq_init_rwin(struct request_sock *req, const struct sock *sk_listener, const struct dst_entry *dst); diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 83829764773b..2a658c2c8903 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -477,9 +477,17 @@ static void tcp_tx_timestamp(struct sock *sk, u16 tsflags) static inline bool tcp_stream_is_readable(const struct tcp_sock *tp, int target, struct sock *sk) { - return (READ_ONCE(tp->rcv_nxt) - READ_ONCE(tp->copied_seq) >= target) || - (sk->sk_prot->stream_memory_read ? - sk->sk_prot->stream_memory_read(sk) : false); + int avail = READ_ONCE(tp->rcv_nxt) - READ_ONCE(tp->copied_seq); + + if (avail > 0) { + if (avail >= target) + return true; + if (tcp_rmem_pressure(sk)) + return true; + } + if (sk->sk_prot->stream_memory_read) + return sk->sk_prot->stream_memory_read(sk); + return false; } /* diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 5af22c9712a6..677facbeed26 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -4751,7 +4751,8 @@ void tcp_data_ready(struct sock *sk) const struct tcp_sock *tp = tcp_sk(sk); int avail = tp->rcv_nxt - tp->copied_seq; - if (avail < sk->sk_rcvlowat && !sock_flag(sk, SOCK_DONE)) + if (avail < sk->sk_rcvlowat && !tcp_rmem_pressure(sk) && + !sock_flag(sk, SOCK_DONE)) return; sk->sk_data_ready(sk);