Re: [PATCH v2] tcp: splice as many packets as possible at once

David Miller
2009-01-27T18:42:33Z

From: David Miller <davem@davemloft.net>
Date: Mon, 26 Jan 2009 22:10:56 -0800 (PST)

> Even for drivers like NIU and myri10ge that do this, they only
> use heuristics or some fixed minimum to decide how much to
> move to the linear area.
>
> Result? Some data payload bits end up there because it overshoots.
...
> I did test this with the NIU driver at one point, and it did not
> change TCP latency nor throughput at all even at 10g speeds.

As a followup, it turns out that NIU right now does this properly.

It only pulls a maximum of ETH_HLEN into the linear area before giving
the SKB to netif_receive_skb().