diff options
| author | Eric Dumazet <edumazet@google.com> | 2015-03-05 08:03:06 -0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2015-03-05 22:31:12 -0500 |
| commit | 6c09fa09d468d730eecd7122122175da772d3b09 (patch) | |
| tree | 65209a0ed3e197683661a5c1ee7d60be634a9c2f /net | |
| parent | e9647d1e74a9778539ad3232e58833210c1935f5 (diff) | |
| download | lwn-6c09fa09d468d730eecd7122122175da772d3b09.tar.gz lwn-6c09fa09d468d730eecd7122122175da772d3b09.zip | |
tcp: align tcp_xmit_size_goal() on tcp_tso_autosize()
With some mss values, it is possible tcp_xmit_size_goal() puts
one segment more in TSO packet than tcp_tso_autosize().
We send then one TSO packet followed by one single MSS.
It is not a serious bug, but we can do slightly better, especially
for drivers using netif_set_gso_max_size() to lower gso_max_size.
Using same formula avoids these corner cases and makes
tcp_xmit_size_goal() a bit faster.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Fixes: 605ad7f184b6 ("tcp: refine TSO autosizing")
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv4/tcp.c | 10 |
1 files changed, 3 insertions, 7 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 9d72a0fcd928..995a2259bcfc 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -835,17 +835,13 @@ static unsigned int tcp_xmit_size_goal(struct sock *sk, u32 mss_now, int large_allowed) { struct tcp_sock *tp = tcp_sk(sk); - u32 new_size_goal, size_goal, hlen; + u32 new_size_goal, size_goal; if (!large_allowed || !sk_can_gso(sk)) return mss_now; - /* Maybe we should/could use sk->sk_prot->max_header here ? */ - hlen = inet_csk(sk)->icsk_af_ops->net_header_len + - inet_csk(sk)->icsk_ext_hdr_len + - tp->tcp_header_len; - - new_size_goal = sk->sk_gso_max_size - 1 - hlen; + /* Note : tcp_tso_autosize() will eventually split this later */ + new_size_goal = sk->sk_gso_max_size - 1 - MAX_TCP_HEADER; new_size_goal = tcp_bound_to_half_wnd(tp, new_size_goal); /* We try hard to avoid divides here */ |