The fact that the answer to your initial question is, "Because it's easier the way I'm doing it now" tells me that I'm putting too much effort into squeezing a tiny speed increase out of this system :)

Parallel::ForkManager is really good at controlling the maximum number of forked children, when you're trying to fork multiple children to solve parts of a large problem in parallel. Unfortunately, my particular problem has a Lot of medium-sized parts, instead of a few large parts (They each wait for network responses, but none do much in the way of calculation; I'd rather be waiting for 10 network results at a time instead of each one sequentially).

Actually, now that I think of it, I could easily break my list of 10000 medium-sized problems into 10 lists of 1000 problems each, and feed each one to a child. This would be much more efficient than forking 10000 children, 10 at a time, each solving only one problem. And it would also be quite easy :)

Thank you for your suggestion!

Alan