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Subject: Re: [PATCH v3 net-next 2/2] tcp: minor optimization around tcp_hdr()
 usage in tcp receive path
To:     Yafang Shao <laoar.shao@gmail.com>,
        Eric Dumazet <edumazet@google.com>
Cc:     Song Liu <songliubraving@fb.com>,
        David Miller <davem@davemloft.net>,
        netdev <netdev@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>
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From:   Eric Dumazet <eric.dumazet@gmail.com>
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Date:   Mon, 28 May 2018 21:53:45 -0700
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On 05/28/2018 05:41 PM, Yafang Shao wrote:

> OK.
> 
> And what about introducing a new helper tcp_hdr_fast() ?
> 
> /* use it when tcp header has not been pulled yet */
> static inline struct tcphdr *tcp_hdr_fast(const struct sk_buff *skb)
> 
> {
> 
>         return (const struct tcphdr *)skb->data;
> 
> }
> 
> 
> That could help us to use this optimized one instead of the original
> one if possilbe.


I would rather not add such macro...

The call site needs to know what is going on, so having a macro like that would not help.