Fwd: receive path with fragmented skbs

Fwd: receive path with fragmented skbs

[Willy Tarreau]

Hi,

you should have posted this to the netdev list : netdev@oss.sgi.com.
You don't need to resend, I have CC'd it.

Willy

On Fri, Jan 30, 2004 at 03:12:24PM -0800, Kallol Biswas wrote:
> Hello,
>       We have been developing drivers and networking software  on
> a 10 gigabit ethernet adapter from S2io Inc (www.s2io.com). There is a
> requirement that the ethernet header, IP+TCP headers have to be cache
> aligned and the payload and the IP+TCP headers have to be in different
> fragments. So we have created receive path skbs with data size big
> enough to hold the ethernet header and two fragments, one fragment for
> the IP+TCP header and the other for payload. The card can  directly dma
> into the three receive scatter buffers when a frame arrives.
> 
> We could not get ping working with this design of receive skbs,
> but if a skb is linearized with skb_linearize() before calling
> netif_rx(), ping works.
> 
> /proc/net/snmp was printed, no frame had any error. Probably no one has
> ever tested the receive path of the stack with fragmented skbs, am I
> right? One of the ways this problem can be debugged is to find out where
> exactly the packets get dropped. Any comment?
> 
> Kallol 
> 
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