diff options
| author | Eric Dumazet <edumazet@google.com> | 2016-08-17 07:48:36 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-08-18 23:27:27 -0700 |
| commit | dca0aaf8472f15836a68bbed8a0ef9ea39e783aa (patch) | |
| tree | 37be0e35a1db4350a50307ec21c2a24e59a13b7a /net/ipv4/tcp_output.c | |
| parent | 53e43f3905f44366acbb5ff6f295d64996fbf6a3 (diff) | |
| download | talos-op-linux-dca0aaf8472f15836a68bbed8a0ef9ea39e783aa.tar.gz talos-op-linux-dca0aaf8472f15836a68bbed8a0ef9ea39e783aa.zip | |
tcp: defer sacked assignment
While chasing tcp_xmit_retransmit_queue() kasan issue, I found
that we could avoid reading sacked field of skb that we wont send,
possibly removing one cache line miss.
Very minor change in slow path, but why not ? ;)
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/tcp_output.c')
| -rw-r--r-- | net/ipv4/tcp_output.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index bdaef7fd6e47..8b45794eb6b2 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -2776,7 +2776,7 @@ void tcp_xmit_retransmit_queue(struct sock *sk) max_segs = tcp_tso_autosize(sk, tcp_current_mss(sk)); tcp_for_write_queue_from(skb, sk) { - __u8 sacked = TCP_SKB_CB(skb)->sacked; + __u8 sacked; int segs; if (skb == tcp_send_head(sk)) @@ -2788,6 +2788,7 @@ void tcp_xmit_retransmit_queue(struct sock *sk) segs = tp->snd_cwnd - tcp_packets_in_flight(tp); if (segs <= 0) return; + sacked = TCP_SKB_CB(skb)->sacked; /* In case tcp_shift_skb_data() have aggregated large skbs, * we need to make sure not sending too bigs TSO packets */ |
