Subject: Re: [PATCH net-next-2.6] rps: consistent rxhash

From: Franco Fichtner <[email-masked]>
Date: Tue, 20 Apr 2010 16:03:17 +0200

Eric Dumazet wrote:
> Le mardi 20 avril 2010 à 14:48 +0200, Franco Fichtner a écrit :
> 
>> I thought about this for some time...
>>
>> Do we really need the port numbers here at all? A simple
>> addr1^addr2 can provide a good enough pointer for
>> distribution amongst CPUs.
>>
>> The real connection tracking is better done locally at the
>> corresponding CPU. That way a potential cache miss can be
>> avoided and the still needed hash calculation for
>> connection tracking will be offloaded.
>>
> 
> Yes, doing the port test/swap is useful in the loopback case 
> (addr1 == addr2).
> 
> This is probably a bit convoluted, but David (and me) found this
> funny ;)
> 
> 

It is funny, but I fail to see the big picture of the
firewall / conntrack application here. It looks like
this is needed for local netperf tests to impress, but
it's a quite special use case, isn't it?