[RFC] Port of DfBSDs new IP Checksum Code

[Gordon Bergling]

Hi Bruce,

Bruce M Simpson wrote:

>On Sat, Aug 06, 2005 at 01:43:29PM +0200, Gordon Bergling wrote:
>  
>
>>I have ported the new IP Checksum Code from DragonflyBSD to FreeBSD.
>>I have a patch available at
>>http://generic.0xfce3.net/freebsd/ipchecksum/20050805-ipchecksum.patch
>>    
>>
>
>There are inline i386 instructions in a machine-independent header; is this
>intentional? Also the asm_ones32() code seems to exist only for i386.
>  
>
I can't say something about the internals of the rework of checksum 
code. I have the commit messages on the hand,
but I can't find something related.

>Without support for other platforms, and some cleanup, I don't think that
>the patch can be committed as is, sadly.
>  
>
As far as I understand the commit messages [1 - 3] correctly the new 
code should be machine independent.
What cleanup do you mean?

>I do like the general idea of rewriting in_cksum() to take advantage of
>branch prediction logic in modern microprocessors, however.
>  
>
I am willing to spend more time on this and, if anyone could point me to 
the right direction regarding the next steps
to get this into the tree.

regards,

    Gordon



[1] http://leaf.dragonflybsd.org/mailarchive/commits/2004-02/msg00187.html
[2] http://leaf.dragonflybsd.org/mailarchive/commits/2004-02/msg00198.html
[3] http://leaf.dragonflybsd.org/mailarchive/commits/2004-02/msg00200.html