The analysis of the idea of virtual space and physical space

In fact, addressing this problem, in the perspective of virtual space, is to find the page table by the linear address. From the physical space point of view, the physical page box is searched through address bus. The middle of the MMU plays a connecting role.

A little more popular, let me give an example.

Virtual space is like the underworld, the physical space is wore, the underworld and the wore each have their own laws, protecting their respective worlds. Make it work correctly and smoothly. The underworld of things can not casually come to wore, and wore things can not casually go to the underworld, such as: wore people have been exploring the existence of the soul there is no underworld, and the underworld of things in fact has been trying to break through the bondage of the underworld came to wore, so there is such a strange place to associate these two places up, Through the bondage, is half step more. This is the link between the yin and yang of the door.

The same is true for the virtual space problem in Linux, so, anyway,

The virtual address cannot access the physical space, and the address returned by the physical space cannot be directly used by the process (the process runs in virtual space and requires a virtual address), but the 2 spaces must also be associated to form a whole, so a hub is needed, as much as a half-step. So the MMU acts as a half-step multi-role, which communicates the virtual space. The MMU resolves the physical address to the CPU through the page table of the virtual space, so the CPU can be addressed to the physical space by address bus.
As for the establishment of the page table, which is a few mapping problems, please see the previous blog post.

The analysis of the idea of virtual space and physical space