How does freeradius calculate the number of required threads?

[Pshem Kowalczyk]

Another update

I've measured the time required by a single function under light load
(5-7req/sec) - on average it takes ~ 0.01 to 0.015 to process
authorize, pre-acct and less then half of that for pre/post proxy.
Under heavier load the boxes still spiral out of control (but only
after some time)  and eventually freeradius disappears of the list of
processes in a puff of white smoke, without leaving any trails in the
logs (except for complains about max of thread running).
I have no idea what causes that, but the fact that it doesn't happen
straightaway suggests some memory problems (but not lack of it, the
boxes have 4GB of RAM).
I think I hit a wall :-( and I don't think rlm_perl is going to make
it to the next phase of the project.

regards
pshemko