Andrey Petrov wrote:

>>I'll take a look at kern/13807 and see if it fixes my problems.
> 
> You can also try NFS without IPsec, so problem will be more localized,
> it would be interesting to know how -current does in your setup.

I applied the patch from kern/13807 and it makes things a lot better! 
This is my current statistics and it looks normal:

131 mbufs in use:
         128 mbufs allocated to data
         2 mbufs allocated to packet headers
         1 mbufs allocated to socket names and addresses
136/144 mapped pages in use
340 Kbytes allocated to network (93% in use)
0 requests for memory denied
0 requests for memory delayed
0 calls to protocol drain routines

I'll post more statistics later...

Martti