> limitations of rr seem to suggest that it is almost of no use for multi-threaded programs Only if your main use case is debugging race conditions only possib

> limitations of rr seem to suggest that it is almost of no use for multi-threaded programs Only if your main use case is debugging race conditions only possible with multiple cores, which is a tiny subset of all bugs. I use rr all the time for a complex multi-threaded (although not extremely parallel) application and it works wonders. It frequently saves me hours of debugging. Practically none of the issues I use it for are race conditions (not because it doesn't work well for those, but because I rarely get any). Even if I had to suffer an 8x slowdown from running it on a single core, it would still be worth it nearly every time.