Hello,

I have two programs with a similar task. One is implemented as a 
kernelspace module and the other as a userspace daemon using 
libnetfilter_queue.
Bot work with the same algorithm and inspect udp packets, send icmp 
packets on special events and receive icmp replys.
I did a throughput test for both the following way:

On my laptop I start the module/daemon and start a netperf udp stream 
from my laptop to a server on LAN. The module/daemon inspect the udp 
stream and does it's work. When the test is over, netperf shows me the 
throughput which came through to the server.
Without any module/daemon running I get ~95mbit/s for my 100mbit LAN.
The funny thing though is, that I get ~85mbit/s with my kernelspace 
module but ~90mbit/s with my userspace daemon.

I thought about explanations for this but I don't come to reasonable 
explanations for this behaviour. Shouldn't the kernelspace module be 
faster? Why is it slower?
Maybe somebody on the list has answers to this questions.
I attached the code of my implementations.

thanks in advance,
Thomas