Take 2: new IP Checksum Code from DragonFlyBSD

[Gordon Bergling]

Hi Scott,

* Thus spake Scott Long (scottl at samsco.org):
> Gordon Bergling wrote:
> >a few month ago I ported DragonFlyBSD's IP checksum code to FreeBSD.
> >My first try wasn't complete and I had forgotten it by the time. Now I
> >hope I have addressed the former mistakes and it maybe included in the
> >tree. ;)
> >
> >The patch can be found at
> >http://generic.0xfce3.net/20060524-ipchecksum.patch
> >
> >This patch modifies the i386, amd64 and pc98 architectures. Matt Dillons
> >new implementation is machine indepement, but there are some asm
> >files/code with seems for me i386 centric. I don't know assembler, so I
> >can't tell much about it.
> >
> >I applied the patch to RELENG_6 and have done a simple netperf
> >benchmark. The machine was a PIII 900.
> >
> >The ministat output:
> >----------------------------------------------------------------------------
> >x netperf-localhost-plain.txt
> >+ netperf-localhost-ncksum.txt
> >+--------------------------------------------------------------------------+
> >|      x     x     x      x        +             ++               +        
> >|
> >|xx    x     x  xx xxx    x  x x  x+x   *+x x +  +++   ++  +  + + +++++   
> >+|
> >|        |__________M_A____________|        |__________A___________|       
> >|
> >+--------------------------------------------------------------------------+
> >    N           Min           Max        Median           Avg        Stddev
> >x  22        707.31        730.41        717.37     718.53909     6.7389076
> >+  22        725.57        746.46       736.535     736.51727     6.3001188
> >Difference at 95.0% confidence
> >	17.9782 +/- 3.96904
> >	2.50205% +/- 0.552377%
> >	(Student's t, pooled s = 6.5232)
> >----------------------------------------------------------------------------
> >
> >Any comments, correctures are very appreciated.
> >
> >best regards,
> >
> >	Gordon
> >
> 
> First, it would be nice to know what netstat options you were using. 
> Second, it would be nice to know if hardware checksum offloading was
> enabled at all on either end of the test.

I don't know what do you mean with netstat options. If you mean the
benchmark, that was the following procedure.

1. /usr/local/netperf/netserver
2. 
for i in 0 1 2 3 4 5 6 7 8 9 
do 
 /usr/local/netperf/netperf -P 0 >> ~/netperf-xyz.txt
done

Step 2 was done twice. I cutted the 'Throughput' fields out of the
netperf-xyz.txt, for use with ministat. The nic I had used is a simple

| fxp0: <Intel 82550 Pro/100 Ethernet> port ...

I havn't enabled any hardware checksum offloading as far as I
know.

Please let me know, if there are other questions left...


best regards,

	Gordon

-- 
Gordon Bergling <GBergling at 0xfce3.net>	      http://www.0xFCE3.net/
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