From d6a4e26afb80c049e7f94e1b7b506dcda61eee88 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Tue, 26 May 2015 08:55:28 -0700 Subject: [PATCH] tcp: tcp_tso_autosize() minimum is one packet By making sure sk->sk_gso_max_segs minimal value is one, and sysctl_tcp_min_tso_segs minimal value is one as well, tcp_tso_autosize() will return a non zero value. We can then revert 843925f33fcc293d80acf2c5c8a78adf3344d49b ("tcp: Do not apply TSO segment limit to non-TSO packets") and save few cpu cycles in fast path. Signed-off-by: Eric Dumazet Cc: Neal Cardwell Cc: Herbert Xu Acked-by: Neal Cardwell Acked-by: Herbert Xu Signed-off-by: David S. Miller --- net/core/sock.c | 5 ++++- net/ipv4/sysctl_net_ipv4.c | 2 +- net/ipv4/tcp_output.c | 4 ++-- 3 files changed, 7 insertions(+), 4 deletions(-) diff --git a/net/core/sock.c b/net/core/sock.c index 29124fcdc42a..e72633c346b1 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -1581,6 +1581,8 @@ EXPORT_SYMBOL_GPL(sk_clone_lock); void sk_setup_caps(struct sock *sk, struct dst_entry *dst) { + u32 max_segs = 1; + __sk_dst_set(sk, dst); sk->sk_route_caps = dst->dev->features; if (sk->sk_route_caps & NETIF_F_GSO) @@ -1592,9 +1594,10 @@ void sk_setup_caps(struct sock *sk, struct dst_entry *dst) } else { sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM; sk->sk_gso_max_size = dst->dev->gso_max_size; - sk->sk_gso_max_segs = dst->dev->gso_max_segs; + max_segs = max_t(u32, dst->dev->gso_max_segs, 1); } } + sk->sk_gso_max_segs = max_segs; } EXPORT_SYMBOL_GPL(sk_setup_caps); diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c index 841de32f1fee..e64892769607 100644 --- a/net/ipv4/sysctl_net_ipv4.c +++ b/net/ipv4/sysctl_net_ipv4.c @@ -702,7 +702,7 @@ static struct ctl_table ipv4_table[] = { .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec_minmax, - .extra1 = &zero, + .extra1 = &one, .extra2 = &gso_max_segs, }, { diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 534e5fdb04c1..190538a2a88c 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -2088,7 +2088,7 @@ static bool tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle, if (unlikely(!tcp_snd_wnd_test(tp, skb, mss_now))) break; - if (tso_segs == 1 || !max_segs) { + if (tso_segs == 1) { if (unlikely(!tcp_nagle_test(tp, skb, mss_now, (tcp_skb_is_last(sk, skb) ? nonagle : TCP_NAGLE_PUSH)))) @@ -2101,7 +2101,7 @@ static bool tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle, } limit = mss_now; - if (tso_segs > 1 && max_segs && !tcp_urg_mode(tp)) + if (tso_segs > 1 && !tcp_urg_mode(tp)) limit = tcp_mss_split_point(sk, skb, mss_now, min_t(unsigned int, cwnd_quota, -- 2.20.1