Quote:
Im wondering if a kernel module is running in kernel or in user space?
|
A kernel module is not treated differently to other parts of the kernel, apart from being dynamically loadable. It runs in supervisor mode.
Quote:
Is a driver running as kernel module slower than a driver build into kernel?
|
Yes, there is a small penalty because of the extra level of indirection making calls between the module and other kernel services. The fraction would be different depending on the number of calls being made. For most drivers it would not be significant (ie, worth making a module built in).
Quote:
this whole (micro)kernel architecture
|
The Linux kernel is not a microkernel, because it does not have any real separation between the components of the kernel. The kernel of OS X is based on the Mach microkernel, but is something of a hybrid.