From: Changli Gao <xiaosuo@gmail.com>
To: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Patrick McHardy <kaber@trash.net>,
"David S. Miller" <davem@davemloft.net>,
Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>,
akpm@linux-foundation.org, netfilter-devel@vger.kernel.org,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3] netfilter: save the hash of the tuple in the original direction for latter use
Date: Fri, 20 Aug 2010 23:36:44 +0800 [thread overview]
Message-ID: <AANLkTinic7H0r7kAgsBiRAbn7MCeqxA0Gme7oOkmPUdJ@mail.gmail.com> (raw)
In-Reply-To: <1282318163.2484.212.camel@edumazet-laptop>
On Fri, Aug 20, 2010 at 11:29 PM, Eric Dumazet <eric.dumazet@gmail.com> wrote:
> Le vendredi 20 août 2010 à 23:22 +0800, Changli Gao a écrit :
>
>> I should keep the old way, but fix a race.
>>
>> if (unlikely(!nf_conntrack_hash_rnd_initted)) {
>> get_random_bytes(&nf_conntrack_hash_rnd,
>> sizeof(nf_conntrack_hash_rnd));
>> nf_conntrack_hash_rnd_initted = 1;
>> }
>>
>> nf_conntrack_alloc() isn't called with in the nf_conntrack_lock. So
>> the above code maybe executed more than once on different CPUs. It is
>> easy to fix with the cmpxchg() trick.
>
> Sure, please fix the race first.
>
> But as I said, its not critical, if one or two conntracks are hashed on
> wrong basis. They will eventually disappear after timeout.
>
Yes, and it isn't critical. I think this fix should be in a separate patch.
--
Regards,
Changli Gao(xiaosuo@gmail.com)
prev parent reply other threads:[~2010-08-20 15:36 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-08-20 14:53 [PATCH v3] netfilter: save the hash of the tuple in the original direction for latter use Changli Gao
2010-08-20 15:10 ` Eric Dumazet
2010-08-20 15:22 ` Changli Gao
2010-08-20 15:29 ` Eric Dumazet
2010-08-20 15:36 ` Changli Gao [this message]
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