From mboxrd@z Thu Jan  1 00:00:00 1970
From: Cong Wang <cwang@twopensource.com>
Subject: Re: something is wrong in commit 971f10eca1 - tcp: better TCP_SKB_CB
 layout to reduce cache line misses
Date: Wed, 15 Oct 2014 14:25:08 -0700
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Cc: Eric Dumazet <eric.dumazet@gmail.com>,
	David Miller <davem@davemloft.net>,
	Eric Dumazet <edumazet@gmail.com>,
	netdev <netdev@vger.kernel.org>
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On Wed, Oct 15, 2014 at 2:22 PM, Cong Wang <cwang@twopensource.com> wrote:
>
> Meanwhile Eric is debugging it, do you mind to try a followup quick
> fix on your 32bit system?
>
> diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
> index e13d778..12bd3f6 100644
> --- a/net/ipv4/tcp_output.c
> +++ b/net/ipv4/tcp_output.c
> @@ -1006,8 +1006,7 @@ static int tcp_transmit_skb(struct sock *sk,
> struct sk_buff *skb, int clone_it,
>         skb->tstamp.tv64 = 0;
>
>         /* Cleanup our debris for IP stacks */
> -       memset(skb->cb, 0, max(sizeof(struct inet_skb_parm),
> -                              sizeof(struct inet6_skb_parm)));
> +       memset(TCPCB(skb), 0, sizeof(*TCPCB(skb)));


Of course, s/TCPCB/TCP_SKB_CB/. :)

>
>         err = icsk->icsk_af_ops->queue_xmit(sk, skb, &inet->cork.fl);