Schol-R-LEA wrote:
Still, they are described as such not only in the corporate press puffery, but in a number of textbooks and published papers as well... obviously, someone other than their respective marketing depts. feels that they fit the description.
Really? Do you know who exactly, so I can flame
them?
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I suppose that the view in some places is that a system which offloads anything into user space is a micro, without regard to whether it is a general abstraction of the system
Yes, which is why IMO so many people get confused about what a microkernel is. Consider single-address space systems like Singularity... it is clearly a microkernel. It has OS services in separate processes, but there is no concept of "user mode" because it uses software isolation instead of hardware isolation. "User mode" is an implementation detail.
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Part of the matter is the question of, what constitutes a critical kernel service, and what can be safely and efficiently abstracted out to user space?
IMO this question is orthogonal to the question of whether or not something is a microkernel.
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Perhaps what is needed is a layering or spaces - that there be a kernel space, a user space, and a 'service space' which isn't part of the kernel but does have additional protections beyond those of user processes - but that probably complicates issues unnecessarily
Yep. Ever looked at the layering in Minix? It is most definitely unnecessarily complex...