upd: 7.2->8.1 & many networks trouble & flowtable

[Li, Qing]

<snip>

> 
> Here's an example of where disabling the flowtable solved a user's
> problem in October 2010:
> 
> http://forums.freebsd.org/showthread.php?t=18301
> 

<snip>

>
> Additionally I remember 2 or 3 posts to mailing lists here discussing
> how bgpd was taking up 100% CPU (or specifically an entire CPU core).
> I'm not sure what people did to solve that problem, but one has to
> wonder if flowtable was the cause and they simply didn't realise it.
>

  The context of the discussion was Andrey's original email, in which
  he reported multiple issues that include the em driver, routing
daemons,
  flow-table garbage collector taking 100% CPU etc. The last issue
obviously
  relates to the flow-table code, and I was not disputing about that.

  I simply asked for a clarification, which I did not receive a clear
  answer, on whether there are routing issues when flow-table is
disabled.

  The reason why I asked, is because L2/L3 separation work (poorly
named, of course)
  is more about the routing infrastructure changes in the FBSD 8.0
  kernel, whereas the flow-table enhancements deal more with the
connections
  (as detailed in my last email), and it builds on top of the L2/L3
work.

<snip>

> 
> I can't speak for the OP or his situation -- flowtable appears to
"work
> fine for me", but then again none of our RELENG_8 systems do routing
nor
> handle large numbers of routes (very simple single-IP or multi-IP
> systems on two networks).
> 

  See above paragraph ...

  I am going to change the flow-table default setting to "disabled" for
the 
  upcoming 8.2 release while these issues are being resolved, and the 
  documentation is being put in place. 
 
  Sounds reasonable.

  -- Qing