What Does an Idle CPU Do?
"The fundamental axiom here is that at any given moment, exactly one task is active on a CPU."<p>Maybe I missed it, and I did check the earlier post and I understand this is trying to be a simplification, but what was the argument for why I should take the above axiom? Was there one?<p>Or I am just being too literal and all the author is really trying to say is the current task pointer must always be valid, in Linux.  Which is probably true enough (I don't know Linux well) but a much less powerful statement.<p>From the post contents I suspect the author is using OS as a synonym for Linux.