- different structures can contain different fields
- Some functions may not be implemented at all, (i.e. some locks
compile away to nothing for non-SMP builds.)
- - Parameter passing of variables from function to function can be
- done in different ways (the CONFIG_REGPARM option controls
- this.)
- Memory within the kernel can be aligned in different ways,
depending on the build options.
- Linux runs on a wide range of different processor architectures.