Ah, okay. As I said before, I don't know the inner details of how Linux's scheduler actually works. I was under the impression that irq0 (int08h) just directly called the scheduler, which then did its choosing of the next process. But I'm apparently wrong and there's some sort of thing where it first determines whether the scheduler has to call or not. My bad. (Sorry, the only scheduler I've played with is Minix's, and even that I didn't delve very deeply into.