Routing benchmarks

[M. Warner Losh]

In message: <20080909150057.GT1147 at cicely7.cicely.de>
            Bernd Walter <ticso at cicely7.cicely.de> writes:
: On Tue, Sep 09, 2008 at 08:40:53AM -0600, M. Warner Losh wrote:
: > In message: <20080909135021.GR1147 at cicely7.cicely.de>
: >             Bernd Walter <ticso at cicely7.cicely.de> writes:
: > : On Tue, Sep 09, 2008 at 03:33:30PM +0200, Jacques Fourie wrote:
: > : > Hi,
: > : > 
: > : > I've performed some benchmark tests on my Gumstix Connex 400 (Intel
: > : > Xscale PXA 255 CPU clocked at 400MHz) with a netDuo expansion board.
: > : > This board has two smc network interfaces. I configure the gumstix as
: > : > a router and measure network throughput with netperf running on
: > : > seperate boxes on either side of the gumstix. My initial tests showed
: > : > a TCP throughput of 2Mbit/s. After adapting the smc driver to use DMA
: > : > this figure went up to 7Mbit/s. Although this is a significant
: > : > improvement, it still seems to be a bit slow. Does anyone have any
: > : > tips on how I can go about to try and figure out where the bottleneck
: > : > lies?  Initial profiling showed that a significant amount of time was
: > : > spent doing memory to memory copies of data, but after the DMA change
: > : > profiling does not show any obvious culprits.
: > : 
: > : I don't know the PXA255, but I do know the AT91RM9200 and I expect the
: > : PXA255 to be a bit faster.
: > : With the RM9200 I can get ~8Mbit/s routing PPPoE with NAT and small
: > : ipfw table.
: > : This is done with the internal MAC using VLAN, so there is also VLAN
: > : overhead.
: > : Plain routing should be faster.
: > 
: > Does the gumstick have 100BaseTX?  The AT91RM9200 is 10BaseT only...
: > Well, 10Mbps only since the phy is external..
: 
: The RM9200 is definitive 100mbit (MII and RMII interface).

Yea.  You're right...

Warner