Re: [PATCH] Make simple TX hash little endian safe.

[Jarek Poplawski <jarkao2@gmail.com>]

On 21-07-2008 10:48, Andi Kleen wrote:
> From: Andi Kleen <andi@basil.nowhere.org>
> 
> Currently it will not use the lower
> bits at all on big endian system, mapping e.g. all connections to a single
> queue on a local network which only differs in the low bits.

It seems ports could be treated similarly, btw?

Jarek P.

> 
> Also fold the upper 16 bits always in the lower 16bits.
> 
> Signed-off-by: Andi Kleen <ak@linux.intel.com>
> ---
>  net/core/dev.c |    7 +++++--
>  1 files changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/net/core/dev.c b/net/core/dev.c
> index 2eed17b..c35fefc 100644
> --- a/net/core/dev.c
> +++ b/net/core/dev.c
> @@ -1694,8 +1694,11 @@ static u16 simple_tx_hash(struct net_device *dev, struct sk_buff *skb)
>  	ports = (u32 *) (skb_network_header(skb) + (ihl * 4));
>  
>  	hash = 0;
> -	while (alen--)
> -		hash ^= *addr++;
> +	while (alen--) {
> +		hash ^= ntohl(*addr); 
> +		addr++;
> +	}
> +	hash ^= hash >> 16; /* More folding needed? */
>  
>  	switch (ip_proto) {
>  	case IPPROTO_TCP: