From 0d9901df62fe4820aee86b49f1a074cdb5c6928e Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Tue, 5 Jul 2005 15:21:10 -0700 Subject: [TCP]: Break out send buffer expansion test. This makes it easier to understand, and allows easier tweaking of the heuristic later on. Signed-off-by: David S. Miller --- net/ipv4/tcp_input.c | 27 +++++++++++++++++++++++---- 1 file changed, 23 insertions(+), 4 deletions(-) (limited to 'net') diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index b948e4eb39b7..2ef2f355b8b8 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -3300,6 +3300,28 @@ void tcp_cwnd_application_limited(struct sock *sk) tp->snd_cwnd_stamp = tcp_time_stamp; } +static inline int tcp_should_expand_sndbuf(struct sock *sk, struct tcp_sock *tp) +{ + /* If the user specified a specific send buffer setting, do + * not modify it. + */ + if (sk->sk_userlocks & SOCK_SNDBUF_LOCK) + return 0; + + /* If we are under global TCP memory pressure, do not expand. */ + if (tcp_memory_pressure) + return 0; + + /* If we are under soft global TCP memory pressure, do not expand. */ + if (atomic_read(&tcp_memory_allocated) >= sysctl_tcp_mem[0]) + return 0; + + /* If we filled the congestion window, do not expand. */ + if (tp->packets_out >= tp->snd_cwnd) + return 0; + + return 1; +} /* When incoming ACK allowed to free some skb from write_queue, * we remember this event in flag SOCK_QUEUE_SHRUNK and wake up socket @@ -3311,10 +3333,7 @@ static void tcp_new_space(struct sock *sk) { struct tcp_sock *tp = tcp_sk(sk); - if (tp->packets_out < tp->snd_cwnd && - !(sk->sk_userlocks & SOCK_SNDBUF_LOCK) && - !tcp_memory_pressure && - atomic_read(&tcp_memory_allocated) < sysctl_tcp_mem[0]) { + if (tcp_should_expand_sndbuf(sk, tp)) { int sndmem = max_t(u32, tp->rx_opt.mss_clamp, tp->mss_cache_std) + MAX_TCP_HEADER + 16 + sizeof(struct sk_buff), demanded = max_t(unsigned int, tp->snd_cwnd, -- cgit v1.2.1