On Fri, 21 Dec 2007 01:43:07 +0100
Petar Bogdanovic <list+2007@smokva.net> wrote:

> Hi,
> 
> I just lost the wireless-connection to one of my machines after starting
> multiple bittorrent-downloads and a build of devel/pcre. I was able to
> connect with a cable and copied this from /var/log/messages:
> 
> Dec 21 01:01:54 /netbsd: WARNING: mclpool limit reached; increase NMBCLUSTERS
> Dec 21 01:01:54 /netbsd: ath0: ath_rx_proc: no mbuf!
> Dec 21 01:02:25 last message repeated 4111 times
> Dec 21 01:04:26 last message repeated 13765 times
> 
> 
> The server runs netbsd-4-0-RELEASE and I never had any wireless-problems
> with netbsd-4 before.

Connecting to a large bittorrent swarm can generate a considerable
amount of incoming TCP connections. You probably just need to do what
the warning message suggests and increase the number of mbuf clusters.

You can either opt to recompile your kernel with options NMBCLUSTERS, or
edit the default value in the stock kernel by doing e.g:

# gdb --write /netbsd
(gdb) set nmbclusters=4096
(gdb) quit

followed by a reboot.

HTH,
-Tobias