Problems with BCE network adapter (Dell PE2950)

[David Christensen]

> > > Sorry for the top post, but I have just managed to repeat is 
> > > exact crash 
> > > twice on a new PE 1950 system.   I have core files available.
> > > 
> > > It seems that after a couple of reboots the problem goes 
> away. The 
> > > system actually crashed 4 times but 2 of the cores where corrupt.
> > > 
> > > It also seems that the system will be stable if the following 
> > > message is 
> > > not produced shortly after /etc/rc.d/netif start:
> > > 
> > > bce0: /usr/src/sys/dev/bce/if_bce.c(3489): Too many free 
> > > rx_bd (0xFFF9 > 
> > > 0x01FE)!
> > > 
> > 
> > The error indicates that too many receive buffer descriptors
> > were freed from the receive chain.  The driver must be losing
> > count somewhere.  The process for duplicating the error sounds
> > simple enough, how much data is in your NFS mounted directory?
> > Are you using TCP or UDP for the NFS mount?
> > 
> > Any idea what type of network activity is happening just after
> > /etc/rc.d/netif start (DHCP, NTP, anything else)?
> > 
> > Dave
> 
> One other thing, are you using jumbo frames?  What's your MTU setting?
> 

And one more thing.  I've been passing line rate traffic for a few 
hours (with both netperf running the tcp_stream_script and a constant
stream of UDP traffic to the discard server on the FreeBSD system)
and I haven't seen a hiccup yet on the tip of RELENG_6 with jumbo
frames enabled on my Dell PE2950 (one dual-core CPU, 4GB RAM).  Of
course I don't have any real services running on it (load average is
0.19).  Any unusual settings I should be aware of?

Does anyone know a simple way to drive up CPU utilization and consume
large amounts of memory to try and simulate a heavily loaded system?

Dave