tcp: tcp_mark_head_lost() optimization

It will be a bit more expensive to get the head of rtx queue
once rtx queue is converted to an rb-tree.

We can avoid this extra cost in case tp->lost_skb_hint is set.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2017-10-05 22:21:24 -07:00 committed by David S. Miller
parent 4e8cc22803
commit 5e76ee4b8e

View File

@ -2207,12 +2207,12 @@ static void tcp_mark_head_lost(struct sock *sk, int packets, int mark_head)
const u32 loss_high = tcp_is_sack(tp) ? tp->snd_nxt : tp->high_seq;
WARN_ON(packets > tp->packets_out);
if (tp->lost_skb_hint) {
skb = tp->lost_skb_hint;
cnt = tp->lost_cnt_hint;
skb = tp->lost_skb_hint;
if (skb) {
/* Head already handled? */
if (mark_head && skb != tcp_write_queue_head(sk))
if (mark_head && after(TCP_SKB_CB(skb)->seq, tp->snd_una))
return;
cnt = tp->lost_cnt_hint;
} else {
skb = tcp_write_queue_head(sk);
cnt = 0;