vfs.ufs.dirhash_maxmem is a bit low

[João Carlos Mendes Luís]

Dennis Berger wrote:
> My request can we add white kernel message for the behavier of running out of hashmemory? Like it is for running out of open files.
> A message will appear on /dev/console indicating that the dirhash is too low.

I like this.

> Or pointing out in tuning(9) that it should raised of servers with lots of files.

And this.

> Or raised the default from 2MB to 10MB or something.

But not this!  Remember that we still have some servers with low memory 
capacity.

Isn't it possible to make this hash somewhat auto-resizeable?