疑问1GB kernel virtual space address 只能映射到 1GB physical memory?
http://blog.chinaunix.net/uid-13377723-id-2895975.html
其中有一节
The Problem
So, the basic problem here is, the kernel can just address 1 GB of virtual addresses, which can translate to a maximum of 1 GB of physical memory. This is because the kernel directly maps all available kernel virtual space addresses to the available physical memory.
为什么只可以寻址1GB虚拟地址空间?