But what does that even mean? Seriously. An interrupt fires, on a particular clock tick. At that point there are, let's say, 130 instructions in flight. In the

But what does that even mean? Seriously. An interrupt fires, on a particular clock tick. At that point there are, let's say, 130 instructions in flight. In the case of a loop like this one there may be seven instructions being retired per clock-cycle. So, you end up with patterns. I linked to some detailed reverse engineering of which instructions are likely to end up being the victim. One common pattern is that the instruction after an expensive one will have the samples assigned to it, but there's more to it than that - I recommend reading it. TL;DR - I'm not saying you're wrong, it's just that you're not saying anything specific enough for write/wrong to apply. "accurate, to exact instruction" has not been meaningful for sampling profilers for more than 2.5 decades.