diff --git a/include/net/sock.h b/include/net/sock.h index 447fddb384a41..c3af696258feb 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -2378,6 +2378,7 @@ static inline void sk_stream_moderate_sndbuf(struct sock *sk) return; val = min(sk->sk_sndbuf, sk->sk_wmem_queued >> 1); + val = max_t(u32, val, sk_unused_reserved_mem(sk)); WRITE_ONCE(sk->sk_sndbuf, max_t(u32, val, SOCK_MIN_SNDBUF)); } diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 53675e2848411..06020395cc8d0 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -5380,7 +5380,7 @@ static int tcp_prune_queue(struct sock *sk) return -1; } -static bool tcp_should_expand_sndbuf(const struct sock *sk) +static bool tcp_should_expand_sndbuf(struct sock *sk) { const struct tcp_sock *tp = tcp_sk(sk); @@ -5391,8 +5391,18 @@ static bool tcp_should_expand_sndbuf(const struct sock *sk) return false; /* If we are under global TCP memory pressure, do not expand. */ - if (tcp_under_memory_pressure(sk)) + if (tcp_under_memory_pressure(sk)) { + int unused_mem = sk_unused_reserved_mem(sk); + + /* Adjust sndbuf according to reserved mem. But make sure + * it never goes below SOCK_MIN_SNDBUF. + * See sk_stream_moderate_sndbuf() for more details. + */ + if (unused_mem > SOCK_MIN_SNDBUF) + WRITE_ONCE(sk->sk_sndbuf, unused_mem); + return false; + } /* If we are under soft global TCP memory pressure, do not expand. */ if (sk_memory_allocated(sk) >= sk_prot_mem_limits(sk, 0))