[snvzz]

> but it doesn't make the system non-deterministic

Actually, it does. It's possible to calculate WCET involving ram accesses, as the behaviour is deterministic; there's a set latency.

It's not possible whenever SWAP is involved, which is why most of the realtime world simply avoids swap. This is mentioned in the Genode handbook, if you're willing to dig into it more.

[dahart]

I guess I need to clarify I was talking about read/write location determinism, and not timing. Timing could affect things, but it also might not. The question is only whether the same bit was touched, not whether the entire system state is identical in every aspect.

I assumed that swap wasn't involved, and I was even going to mention it but decided against. While it is remotely possible, there's not much reason to suspect swap, Handbrake was actively running, doesn't normally use enough memory to start swapping, and people ripping DVDs usually know not to be doing other things and/or using all their memory while ripping.

That said, are you saying swap in the OS really is non-deterministic by design, or just hard to predict? And what does Genode have to do with this, assuming he wasn't using Genode?