Re: mbuf leak on NetBSD-5 AP when Windows laptop connects

[Roy Marples <roy%marples.name@localhost>]

On Thursday 13 August 2009 09:36:37 Roy Marples wrote:
> Hi List!
>
> I've been running NetBSD-5 on my Access Point for some time, with great
> success.
> However, when a Windows based laptop connects to the network, the AP
> runs out of mbufs in about 45 minutes. This is 100% reproducable with
> minimal traffic from laptop -> AP. When the laptop is turned off, the AP
> is fine and has no trouble talking to my other boxes (1 laptop, 2
> desktops, 1 wii).
>
> I have attached an mbuf watchdog script that runs as a cron job every 5
> minutes to check that total claimed mbufs do not exceed 1000 - if it
> does, it restarts the AP interface. Currently, it is emailing me every
> 15 minutes.
> Here is some sample output
>
> 1059 mbufs in use:
>       1033 mbufs allocated to data
>       24 mbufs allocated to packet headers
>       2 mbufs allocated to socket names and addresses
> 4 calls to protocol drain routines
> mbufs exceed 1000 - restarting ath0
>
>
> The AP tracks the netbsd-5 branch and is an amd64 with an ath(4)
> wireless network card.
> This behaviour was present both before and after the pullup was made to
> bring the new ath HAL into netbsd-5.
> The AP also runs PF, PPPoE and ALTQ in the kernel.
> options MBUFTRACE has been enabled and only "unknown data" is growing,
> which is of no help for working out where the problem lies.
>
> The Windows laptop is a Lenovo T500 with an Intel Wifi Link 5100 AGN
> network card. It ran Vista32 an now Windows7 64, both with this problem.

I've now tracked this down to altq - either used in pf OR altqd alongside 
ipfilter.

Would a tcpdump help track this down further?

Thanks

Roy