> I presume you are saying that since in Linux processes and threads are "the same" there is no need to distinguish whether the process being switched in shares the same address space.
That's right. Threads share everything but their stack.
> Does this mean that there is a missed optimization on Linux to preserve some virtually-addressed caches and tables when switching to thread/process that shares the same address space?
I'm not entirely sure I understand your question. What scenario do you have in mind?