dev.bce.X.com_no_buffers increasing and packet loss

Ian FREISLICH ianf at clue.co.za
Mon Mar 8 14:45:27 UTC 2010


Pyun YongHyeon wrote:
> On Fri, Mar 05, 2010 at 11:16:41PM +0200, Ian FREISLICH wrote:
> > Pyun YongHyeon wrote:
> > > Thanks for the info. Frankly, I have no idea how to explain the
> > > issue given that you have no heavy load.
> > 
> > How many cores would be involved in handling the traffic and runnig
> > PF rules on this machine?  There are 4x
> > CPU: Quad-Core AMD Opteron(tm) Processor 8354 (2194.51-MHz K8-class CPU)
> > In this server.  I'm also using carp extensively.
> > 
> 
> pf(4) uses a single lock for processing, number of core would have
> no much benefit.

What's interesting is the effect on CPU utilisation and interrupt
generation that net.inet.ip.fastforwarding has:

net.inet.ip.fastforwarding=1
interrupt rate is around 10000/s per bce interface
cpu 8.0% interrupt

net.inet.ip.fastforwarding=0
interrupt rate is around 5000/s per bce interface
cpu 13.0% interrupt
It also appears to not drop packets, but I'll have to watch it for longer.

Ian

--
Ian Freislich


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