HTB vs CoDel performance

Hi,

I'm testing htb performance on a gigabit router running 2.6.32 kernel.
Packet path: PC1 ---> Router LAN port ---> Router WAN port ---> PC2

pfifo_fast: 920Mbps
htb: 750Mbps, ~20% drops compared to pfifo_fast

htb tc commands as below,
# tc qdisc add dev eth10 root handle 20: htb default 1
# tc class add dev eth10 parent 20 classid 20:1 htb prio 2 rate
1024Mbit ceil 1024Mbit burst 1281408b cburst 1281408b

The performance drop seems caused by the complex htb enqueue/dequeue algorithm.

I had a quick look at CoDel code, seems it does not have so complex
data structure as HTB.
I'm going to backport CoDel. Is this a good choice?
Can I gain similar performance as pfifo_fast?

Thanks,
Lin Ming