Well, conservative GC is known for this kind of problems, but the overhead is supposed to be generally bounded. I'm not sure about pathological cases; Go may have hit one back then. It highly depends on the circumstances. For example, PLT Scheme used to use the (conservative) Boehm GC in the past, and they've since replaced it, but I don't recall any such problem while they were using it (aside from the somewhat larger but bounded memory usage).