Making stestr scheduler smarter with a lot of threads

Hi, Currently, it looks like stestr calculate which thread should run which test at the beginning, by calculating some partition, and then launch all tests at once. With a lot of threads, the result is, at the end, only a few cores are in use, with all the others being idle. Would there be a way to have a pool of available threads instead, and have stestr to give threads something to eat when they are available, instead of the current way? How much work would that be? Cheers, Thomas Goirand (zigo)