Messages in this thread Patch in this message | | | Subject | Re: [PATCH net-next] tcp: introduce skb_rbtree_walk_safe() and use it in tcp_clean_rtx_queue() | From | Eric Dumazet <> | Date | Wed, 28 Nov 2018 08:53:58 -0800 |
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On 11/28/2018 06:44 AM, Eric Dumazet wrote: >
> Because we can break of the loop if the current skb is not fully acked. > > So your patch would add unnecessary overhead, since the extra sk_rb_next() > could add more extra cache line misses.
I am testing the following optimization, since we can avoid the rb_next() call when we reached snd_una
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index f32397890b6dcbc34976954c4be142108efa04d8..6829e470f0c186a73c34dca414cd4a2b379baded 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -3126,7 +3126,8 @@ static int tcp_clean_rtx_queue(struct sock *sk, u32 prior_fack, if (!fully_acked) break; - next = skb_rb_next(skb); + next = (scb->end_seq == tp->snd_una) ? NULL : skb_rb_next(skb); + if (unlikely(skb == tp->retransmit_skb_hint)) tp->retransmit_skb_hint = NULL; if (unlikely(skb == tp->lost_skb_hint))
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