From d6a4e26afb80c049e7f94e1b7b506dcda61eee88 Mon Sep 17 00:00:00 2001
From: Eric Dumazet <edumazet@google.com>
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 <edumazet@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
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 29124fcdc42a6..e72633c346b19 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 841de32f1fee4..e64892769607a 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 534e5fdb04c11..190538a2a88ce 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,
--
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