Re: [PATCH v2] Receive Packet Steering

[Tom Herbert <therbert@google.com>]

On Fri, Jul 17, 2009 at 11:08 AM, David Miller<davem@davemloft.net> wrote:
> From: Tom Herbert <therbert@google.com>
> Date: Fri, 17 Jul 2009 11:05:58 -0700
>
>> The advantage is that Toeplitz, or any reasonable device provided
>> hash, allows packet steering to be done without taking any cache
>> misses on the packet itself.  In particular, this helps with a NIC
>> that just provides Toeplitz hash (without multiQ),
>
> Good point.
>
> Depending upon the cache line size, however, we might have
> at least the IP header in the cpu cache at this point since
> eth_type_trans() had to pull in the entire ethernet header
> underneath.
>

eth_type_trans does not need to even be called assuming that the
packet type information can be inferred from the RX descriptor.  We
are doing steering completely based on contents of the RX descriptor.