[moonchild]

You're conflating two separate things. There's hardware-level page size, which is the logical unit of the mmu. On x86, this is always 4k. The kernel can map mmu-level pages into the address space of running processes. As an optimization, it might always map these mmu-level pages in batches. The batch size comprises the virtual page size; for instance, it could always map in batches of 4, for a 16k virtual page. But the CPU-level page size is completely fixed.