Re: [PATCH v6] net: add Faraday FTMAC100 10/100 Ethernet driver

[Eric Dumazet]

Le mardi 01 mars 2011 Ã 13:51 +0800, Po-Yu Chuang a Ãcrit :
> On Tue, Mar 1, 2011 at 1:45 PM, Eric Dumazet <eric.dumazet@xxxxxxxxx> wrote:

> > I am only wondering then if not using fragments would be faster then
> > (eventually doing copybreaks for small frames like tg3)
> 
> Although not many circumstances are tested.
> iperf shows that it is a little faster to use fragments than memcpy, so...

This might be a side effect of skb->truesize being smaller with
fragments than "regular packets" and socket backlog congestion.

If a full page was really accounted for in skb->truesize, instead of
used length, performance might be the same or lower :(

-	skb->truesize += length;
+	skb->truesize += PAGE_SIZE;

This has nothing to do with your driver, but a core implementation
detail.



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