From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Miller <davem@davemloft.net>
Subject: Re: [PATCH next-net] ipv6: Use hlist_for_each_entry_rcu_bh() in
 ipv6_chk_same_addr()
Date: Tue, 01 Nov 2011 05:06:36 -0400 (EDT)
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From: RongQing Li <roy.qing.li@gmail.com>
Date: Tue, 1 Nov 2011 17:05:19 +0800

> 2011/11/1 David Miller <davem@davemloft.net>:
>> From: RongQing Li <roy.qing.li@gmail.com>
>> Date: Tue, 1 Nov 2011 16:33:49 +0800
>>
>>> Yes, But I think the code readable is not good,
>>
>> It is wasteful to add multiple BH disables and RCU memory
>> barriers in code paths where it is not necessary.
>>
>> Your patch fixes no real bug, and adds a regression.
>>
> 
> hlist_for_each_entry_rcu_bh() does not disable BH,
> it only check If BH is disabled.
> 
> These codes is different from normal RCU convention.

But adding _rcu does add memory barriers.