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

Li, Qing qing.li at bluecoat.com
Wed Nov 24 21:43:40 UTC 2010


> 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


> 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
  flow-table garbage collector taking 100% CPU etc. The last issue
  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

  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
  (as detailed in my last email), and it builds on top of the L2/L3


> I can't speak for the OP or his situation -- flowtable appears to
> fine for me", but then again none of our RELENG_8 systems do routing
> 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
  upcoming 8.2 release while these issues are being resolved, and the 
  documentation is being put in place. 
  Sounds reasonable.

  -- Qing

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