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From: David Miller <davem@davemloft.net>
Subject: Re: [RFC] Kernel unaligned access at __skb_flow_dissect
Date: Fri, 29 Jan 2016 11:08:11 -0800 (PST)
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From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Fri, 29 Jan 2016 10:40:10 -0800

> I would try following ixgbe fix (sorry, totally untested, but you get
> the idea...)
> 
> diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
> index c4003a88bbf6..7ba64ed463a6 100644
> --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
> +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
> @@ -1525,7 +1525,7 @@ static bool ixgbe_alloc_mapped_page(struct ixgbe_ring *rx_ring,
>  
>  	bi->dma = dma;
>  	bi->page = page;
> -	bi->page_offset = 0;
> +	bi->page_offset = NET_IP_ALIGN;
>  
>  	return true;
>  }

Hmmm, wouldn't this waste 2 bytes on all pages?  Or just the head one with the headers?