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See Memory Configurations for additional information

Address Spaces

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, Memory Allocators, and User Mode

What would happen if you tried to create a pthread in the PROTECTED or KERNEL build? The effect of these address space differences become very pronounced. pthreads are, by their very definition, user-space threads. That means that the OS will attempt to create a user-space environment for the pthread: The thread's stack and other resources.

And when the pthread is started, it will be started in user mode, not kernel mode.

It would require a significant change to the OS to alter that behavior and that is not under consideration (because the change is also inappropriate).

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