The question asked by the interlocutor in the interview. I always thought this was a stupid question.
Suppose one processor, not dual-core.
Yes, if DMA is not available. In this case, you can use the CPU to move data from I / O to I / O through the central memory, if the I / O bandwidth on both devices is high enough, you can saturate the CPU efficiently.
Yes. A simple one has two processes that use the entire processor, and another that uses all the I / O. It will do it. The real problem is what I / O is talking about. There are several buses in any system, and they can all be connected at any given time.
I would also like to find places where IO devices will be virtualized and encrypted. This is probably an unusual case, but not an impossible case.
Yes, you can! (Sounds like a cliché?) But in fact there is such a thing as not blocking I / O. You can do many things as long as your data uses 100% IO.