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Re: BNX Double Buffer Allocation

On Fri, Aug 29, 2008 at 02:58:28PM -0700, Aaron J. Grier wrote:
> On Fri, Aug 29, 2008 at 11:45:50PM +0200, Manuel Bouyer wrote:
> > > is there any way to find out how many buffers each connection is using?
> > > a combination of netstat -a and -m?
> > 
> > netstat -a; size of both queues. A mbuf cluster is 2k, so the number
> > of mbcl is easy to find ...
> # netstat -m   
> 1870 mbufs in use:
>         1869 mbufs allocated to data
>         1 mbufs allocated to packet headers
> 0 calls to protocol drain routines
> netstat -a shows nothing on the queues.
> I assume NAT and firewall state also allocate mbufs?  how do I track
> them down?

This I'm not sure. A kernel built with 'options MBUFTRACE' should give
more details about this, but I don't know which tools allows to see
the infos. Maybe netstat will notice if a kernel is compiled with or without

> > > this is all still assuming it is an mbuf issue and something else.
> > > I still don't know what else draws from mclpool.
> >
> > Almost anything that needs to store data in mbufs.
> mbufs are the only data structures allocated out of mclpool?

mclpool is for mbuf clusters, not mbufs. But basically yes, mbuf clusters
are always attached to mbufs.

Manuel Bouyer <>
     NetBSD: 26 ans d'experience feront toujours la difference

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