kernel mode PPPoE on linux

["Timur Irmatov" <irmatov@gmail.com>]

Hi, all!

Does anybody have an experience with kernel mode PPPoE? PPPoE module
in Linux kernel is marked as experimental, so I am not sure about
using it on production server.

Recently we have installed two Debian Etch servers to provide PPPoE
access. Each server is configured with 510 addresses, and in peak
hours each handles about 400 PPPoE sessions. Currently, both machines
use user mode PPPoE. (BTW, machines are AMD Athlon 64 2Ghz). They seem
to perform fine, no slowdowns, but there's high number of context
switches (~50k) and interrupts (8-10k).

Is there any (dis-)advantages in switching to kernel mode?

As to number of interrupts, what is usually upper limit on interrupt
rate? Will it be better to install intel (or other) network card with
NAPI?

Any hints will be greatly appreciated!

--
Timur Irmatov, xmpp:irmatov@jabber.ru