Re: BNX Double Buffer Allocation

[David Young <dyoung%pobox.com@localhost>]

On Thu, Aug 28, 2008 at 11:13:12AM -0700, Aaron J. Grier wrote:
> On Tue, Aug 26, 2008 at 04:03:48PM -0500, David Dudley wrote:
> > The system compiled with no problem, however when I start the system
> > with 2 network interfaces connected (bnx0 & bnx1), I get "WARNING:
> > mclpool limit reached; increase NMBCLUSTERS", and both network
> > interfaces stop.  I don't get a panic, just the network connections
> > won't pass data any more.
> 
> I have seen this on our NAT at work as well.  bumping NMBCLUSTERS has
> helped, but what I don't understand is why the network gets completely
> wedged.  why can't it recover by dropping packets and reclaiming mbufs?

Drivers for network interfaces reserve many mbufs for receiving packets,
and they are not smart enough to shrink their reservation.

Dave

-- 
David Young             OJC Technologies
dyoung%ojctech.com@localhost      Urbana, IL * (217) 278-3933 ext 24