vlan patch

[Ragnar Lonn]

Gleb Smirnoff wrote:

>Although the memory overhead is not noticable on modern i386 and amd64
>PCs I don't think that we should waste so much memory. We should keep
>in mind the existence of embedded architectures with little memory.
>
>In most cases people use 10 - 30 VLANs. I suggest to use a hash, like it
>is already done in ng_vlan(4). This hash makes every sixteenth VLAN to fall
>into same slot. Since most people allocate VLAN ids contiguously the hash
>distribution should be good.
>
>Moreover, I suggest Yar and Ruslan to work together and make the hash code
>shared between vlan(4) and ng_vlan(4), not copy-and-pasted.
>  
>

It looks as if ng_vlan implements a standard hash. Wouldn't a hashtree 
be a good
compromise between speed and memory usage?  Of course, a 16-slot hash is 
a lot
better than no hash at all :-)

  /Ragnar