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| author | Eric Dumazet <[email protected]> | 2016-08-17 14:48:36 +0000 |
|---|---|---|
| committer | David S. Miller <[email protected]> | 2016-08-19 06:27:27 +0000 |
| commit | dca0aaf8472f15836a68bbed8a0ef9ea39e783aa (patch) | |
| tree | 37be0e35a1db4350a50307ec21c2a24e59a13b7a /net/ipv4/tcp_output.c | |
| parent | Merge branch 'bridge-vlan-stats-with-flags' (diff) | |
| download | kernel-dca0aaf8472f15836a68bbed8a0ef9ea39e783aa.tar.gz kernel-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 <[email protected]>
Acked-by: Neal Cardwell <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
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 */ |