[HEADS UP] Significant TCP work committed to head

Lawrence Stewart lstewart at freebsd.org
Sat Nov 13 00:54:53 UTC 2010


On 11/13/10 04:58, Kevin Oberman wrote:
>> Date: Fri, 12 Nov 2010 20:35:45 +1100
>> From: Lawrence Stewart <lstewart at freebsd.org>
>> Sender: owner-freebsd-current at freebsd.org
>>
>> Hi All,
>>
>> A quick note that this evening, I made the first in a series of upcoming
>> commits to head that modify the TCP stack fairly significantly. I have
>> no reason to believe you'll notice any issues, but TCP is a complex
>> beast and it's possible things might crop up. The changes are mostly
>> related to congestion control, so the sorts of issues that are likely to
>> crop up if any will most probably be subtle and difficult to even
>> detect. The first svn revision in question is r215166. The next few
>> commits I plan to make will be basically zero impact and then another
>> significant patch will follow in a few weeks.
>>
>> If you bump into an issue that you think might be related to this work,
>> please roll back r215166 from your tree and attempt to reporoduce before
>> reporting the problem. Please CC me directly with your problem report
>> and post to freebsd-current@ or freebsd-net@ as well.
>>
>> Lots more information about what all this does and how to use it will be
>> following in the coming weeks, but in the meantime, just keep this note
>> in the back of your mind. For the curious, some information about the
>> project is available at [1,2].
>>
>> Cheers,
>> Lawrence
>>
>> [1] http://caia.swin.edu.au/freebsd/5cc/
>> [2]
>> http://www.freebsd.org/news/status/report-2010-07-2010-09.html#Five-New-TCP-Congestion-Control-Algorithms-for-FreeBSD
> 
> Lawrence,
> 
> Great news! I've been looking forward to having these congestion
> algorithms for a while and this is clearly a big step to getting there.

HTCP and CUBIC should become available next week (the zero impact
commits I mentioned in my email above) and then a chunk of additional
infrastructure is needed in order to add our delay based algorithm
modules to the tree. We anticipate having all the code in head by the
time Christmas rolls around assuming no major issues crop up.

> Do you intend to MFC this for 8.2?

No. I wouldn't feel comfortable unleashing this on people with only 2
weeks of soak time in head. The current MFC schedule is 3 months from
yesterday, so it will be in stable/8 and hopefully stable/7 as well
shortly after 8.2 and 7.4 are released.

Cheers,
Lawrence


More information about the freebsd-current mailing list