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From: "jiangtao.jit" <jiangtao.jit@gmail.com>
To: "Francois Romieu" <romieu@fr.zoreil.com>
Cc: "netdev" <netdev@vger.kernel.org>
Subject: Re: problem with function vlan_get_protocol()
Date: Sun, 17 Jul 2011 16:15:51 +0800	[thread overview]
Message-ID: <201107171615491568697@gmail.com> (raw)
In-Reply-To: 201107171253127340006@gmail.com


Thanks a lot Francois
thank you for your explanation

--
jiangtao



发件人： Francois Romieu 
发送时间： 2011-07-17  15:49:00 
收件人： jiangtao.jit 
抄送： netdev 
主题： Re: problem with function vlan_get_protocol() 
 
jiangtao.jit <jiangtao.jit@gmail.com> :
[...]
> do we need an else branch on pointer protop failed ?  through the else is unlikely 
> 
>  if (likely(protop))
>  protocol = *protop;
>     else
>  protocol = proto;
> 
> is it necessary ?
The else branch signals that skb_header_pointer uncloaked a really tiny
ethernet frame : the content of proto is not even initialized (stack
allocation), whence irrelevant. In such circumstances the default
initialization value of protocol (0) does not seem too bad.
-- 
Ueimor

  parent reply	other threads:[~2011-07-17  8:16 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-07-17  4:53 problem with function vlan_get_protocol() jiangtao.jit
2011-07-17  7:34 ` Francois Romieu
2011-07-17  8:15 ` jiangtao.jit [this message]
  -- strict thread matches above, loose matches on Subject: below --
2011-07-17  3:51 jiangtao.jit
2011-07-17  4:17 ` David Miller

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