From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Miller <davem@davemloft.net>
Subject: Re: [PATCH v2 net-next] tcp: remove dst refcount false sharing for
 prequeue mode
Date: Mon, 08 Sep 2014 15:41:08 -0700 (PDT)
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From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Mon, 08 Sep 2014 14:30:42 -0700

> In the worst case, here is what is happening :
> 
> sk_rx_dst is checked and invalidated in tcp_v4_do_rcv()
> 
> Next packets coming from prequeue might then have a NULL dst, and
> we'll do nothing special (sk_rx_dst will stay NULL), because we do
> handle NULL dst properly in inet_sk_rx_dst_set() and
> inet6_sk_rx_dst_set() 
> 
> But next packet to be processed (either in non prequeue mode or
> prequeue) will carry skb->dst and we will set sk->sk_rx_dst
> 
> I decided to not copy/paste the tests we do in the family dependent
> parts, because it was not worth the pain.

I must have mis-read some of these code paths, let me look over it
again, thanks!