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From: Ian FREISLICH <ianf@clue.co.za>
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Date: Wed, 10 Mar 2010 07:48:11 +0200
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Cc: current@freebsd.org
Subject: Re: dev.bce.X.com_no_buffers increasing and packet loss 
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Pyun YongHyeon wrote:
> On Tue, Mar 09, 2010 at 11:55:30PM +0200, Ian FREISLICH wrote:
> > I set the RX as high as 512 in 64 quanta but it made little difference
> > to the interrupt rate.  At times where we experience the packet
> > loss and com_no_buffers increases, the interrupt rate on between 1
> > and 3 of the 4 bce interfaces fell from about 3200/s to 130/s.
> > 
> 
> BD chain is just one of parameters. bce(4) controllers also provide
> more advanced features that fine control interrupt moderation(TX/RX
> ticks). It's hard to explain all the details so you may want to
> read public data sheet of bce(4).

Thanks.  I'll have a read over that.

I meant to state that above that whenever the interrupt rate on a
controller (or several) falls off, the interrupt CPU usage climbs
from about 4% to about 20%.  So it seems like something is happening
on host that jams up interrupt processing.

Ian

--
Ian Freislich