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From: David Miller <davem@davemloft.net>
To: eric.dumazet@gmail.com
Cc: tom@herbertland.com, netdev@vger.kernel.org
Subject: Re: [PATCH v2 net-next 1/5] net: Get skb hash over flow_keys structure
Date: Tue, 12 May 2015 10:30:46 -0400 (EDT)	[thread overview]
Message-ID: <20150512.103046.1807865055959150687.davem@davemloft.net> (raw)
In-Reply-To: <1431406606.566.62.camel@edumazet-glaptop2.roam.corp.google.com>

From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Mon, 11 May 2015 21:56:46 -0700

> On Mon, 2015-05-11 at 20:26 -0700, Tom Herbert wrote:
 ...
> This (2) is not a multiple of 4, so some arches will have unaligned word
> accesses ?
 ...
>> -static __always_inline u32 __flow_hash_3words(u32 a, u32 b, u32 c, u32 keyval)
>> +static __always_inline u32 __flow_hash_words(u32 *words, u32 length, u32 keyval)
>>  {
>> -	return jhash_3words(a, b, c, keyval);
>> +	return jhash2(words, length, keyval);
>> +}
>> +
> 
> -> crash or very slow on MIPS.

Yeah you really can't do this.  You must only pass 4-byte aligned items
into the hash function.

  reply	other threads:[~2015-05-12 14:30 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-05-12  3:26 [PATCH v2 net-next 0/5] net: Increase inputs to flow_keys hashing Tom Herbert
2015-05-12  3:26 ` [PATCH v2 net-next 1/5] net: Get skb hash over flow_keys structure Tom Herbert
2015-05-12  4:56   ` Eric Dumazet
2015-05-12 14:30     ` David Miller [this message]
2015-05-12  3:26 ` [PATCH v2 net-next 2/5] net: Add full IPv6 addresses to flow_keys Tom Herbert
2015-05-12  3:26 ` [PATCH v2 net-next 3/5] net: Add VLAN ID " Tom Herbert
2015-05-12  3:26 ` [PATCH v2 net-next 4/5] net: Add IPv6 flow label " Tom Herbert
2015-05-12  3:26 ` [PATCH v2 net-next 5/5] net: Add GRE keyid in flow_keys Tom Herbert
2015-05-12  4:33   ` Eric Dumazet
2015-05-12  4:50     ` Eric Dumazet
2015-05-12 14:51       ` Tom Herbert
2015-05-12 16:06         ` Eric Dumazet
2015-05-15 12:48           ` [PATCH net-next] net: fix two sparse errors Eric Dumazet
2015-05-15 14:35             ` Sabrina Dubroca
2015-05-15 14:52               ` Eric Dumazet
2015-05-15 15:23                 ` Sabrina Dubroca
2015-05-15 16:14                   ` Eric Dumazet
2015-05-15 15:27               ` Tom Herbert
2015-05-15 15:54                 ` Sabrina Dubroca
2015-05-15 16:19                   ` David Miller
2015-05-15 16:26                     ` Sabrina Dubroca
2015-05-15 15:11             ` Tom Herbert
2015-05-17 18:11             ` David Miller

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