For network apps that create one thread per connection (like Pound), threadcount can become a bottleneck on the number of concurrent connections you can server.

I'm running FreeBSD 8 x64:

```
$ sysctl kern.maxproc
kern.maxproc: 6164
$ sysctl kern.threads.max_threads_per_proc
kern.threads.max_threads_per_proc: 1500
$ limits
Resource limits (current):
cputime infinity secs
filesize infinity kB
datasize 33554432 kB
stacksize 524288 kB
coredumpsize infinity kB
memoryuse infinity kB
memorylocked infinity kB
maxprocesses 5547
openfiles 200000
sbsize infinity bytes
vmemoryuse infinity kB
pseudo-terminals infinity
swapuse infinity kB
```

I want to increase kern.threads.max_threads_per_proc to 4096. Assuming each thread starts with a stack size of 512k, what else do I need to change to ensure that I don't hose my machine?