rlm_ippool slowness

Hi, I modified rlm_ippool.c to create a hash key against Calling-Station-Id, which is unique across my NAS. I only have one NAS (it's a test enviornment) so no worries about duplicate ports keys. However, I find radiusd goes up to 97% CPU when I use this IP allocation method. If I don't use any server-side IP allocation, I get CPU use hovering around 4%. I can't use an integer like Nas-Id to hash against because it's not a unique value on my NAS, hence I had to modify rlm_ipool.c. So I can't easily check whether the problem is in the rest of rlm_ippool.c or in the change of the hashing method that I've done. Thoughts? Thanks, Chris