Why userspace rather than writing kernel space modules?

[Ondrej Filip]

On Mon, 11 Jun 2001, Daniel Holmlund wrote:

> Hi everyone,

Hello!

> I'm a newbie to BIRD who ran across it from freshmeat.net.
>
> Being a newbie, I have some newbie questions.
>
> How efficient is it to sync with kernel space routing tables if the
> routing tables change rapidly?

Look into source code. I'm not sure, but of course it's not too efficient.

> How often does a routing table change with a typical server
> configuration and typical server traffic?

It depends on the network topology. In my small network it happens every
minute. But I don't run BGP in it. I can imagine, it can happen much more
often.

> Lastly besides the portability, why implement a userspace daemon that
> is required to sync with the kernel when kernel space modules could
> be written to directly manipulate the routing tables themselves?

Last I met Martin, we discussed about building BIRD as a linux kernel
module. Let's say, it's a future plan.

> Thanks for answering these questions. Currently, I am EXTREMELY
> interested in this project, and would like to potentially put some
> development time into BIRD.

Welcome!

>
> Daniel Holmlund
>

			Kind regards
				Ondrej Feela Filip