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From: Chuck Lever <chuck.lever@oracle•com>
To: "Aurélien Charbon" <aurelien.charbon@ext•bull.net>
Cc: Mailing list NFSv4 <nfsv4@linux-nfs•org>,
	netdev ML <netdev@vger•kernel.org>, Neil Brown <neilb@suse•de>
Subject: Re: [PATCH 1/1] NFS: change the ip_map cache code to handle IPv6 addresses
Date: Thu, 09 Aug 2007 11:14:45 -0400	[thread overview]
Message-ID: <46BB2F65.4080602@oracle.com> (raw)
In-Reply-To: <46BB2E01.2010406@ext.bull.net>

[-- Attachment #1: Type: text/plain, Size: 999 bytes --]

Aurélien Charbon wrote:
>>> @@ -112,12 +112,16 @@
>>>      return (hash ^ (hash>>8)) & 0xff;
>>>  }
>>>  #endif
>>> +static inline int hash_ip6(struct in6_addr ip)
>>> +{
>>> +        return (hash_ip(ip.s6_addr32[0]) ^ hash_ip(ip.s6_addr32[1]) 
>>> ^ hash_ip(ip.s6_addr32[2]) ^ hash_ip(ip.s6_addr32[3])) ;
>>> +}
>>
>>
>> How have you tested the effectiveness of the new hash function?
> 
> I have not tested that point but I can easily imagine there are better 
> solutions.
> Perhaps we can keep the same function for an IPv4 address (only taking 
> the 32 bits of IPv4 addr), and then design one for IPv6 addresses.

I see that, to generate the hash, you would be xor-ing the FF and 00 
bytes in the canonicalized IPv4 address.  Yes, perhaps a better function 
is needed, or as you say, one specifically for IPv6 and one for 
canonicalized IPv4.

> Do you have any suggestion on that ?

I don't have anything specific, but you may find something useful if you 
poke around elsewhere under net/.

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  reply	other threads:[~2007-08-09 15:16 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-08-09  7:22 [PATCH 1/1] NFS: change the ip_map cache code to handle IPv6 addresses Aurélien Charbon
2007-08-09 12:16 ` Chuck Lever
2007-08-09 15:08   ` Aurélien Charbon
2007-08-09 15:14     ` Chuck Lever [this message]
2007-08-10  1:11       ` Neil Brown
2007-08-10  1:06 ` Neil Brown
  -- strict thread matches above, loose matches on Subject: below --
2007-08-23 13:18 Aurélien Charbon
2007-08-23 15:32 ` Brian Haley
2007-09-06 11:30   ` Aurélien Charbon
2007-09-06 16:16     ` Brian Haley
2007-08-23 15:39 ` Chuck Lever

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