How are page tables implemented?

The hardware implementation of page table can be done by using dedicated registers. But the usage of register for the page table is satisfactory only if page table is small. If page table contain large number of entries then we can use TLB(translation Look-aside buffer), a special, small, fast look up hardware cache.

What is a page walk?

It is a part of the chip’s memory-management unit (MMU). The page walk is time-consuming when compared to the processor speed, as it involves reading the contents of multiple memory locations and using them to compute the physical address.

What way virtual memory is normally implemented?

Virtual memory is a section of a hard disk that’s set up to perform as the computer’s RAM. It is commonly implemented by demand paging or Demand segmentation.

What is the purpose of a page table?

A page table is the data structure used by a virtual memory system in a computer operating system to store the mapping between virtual addresses and physical addresses.

Does each process have a page table?

Yes every process has its own pagetables. They might be shared with the parent process(copy on write) or with other processes(shared memory). But in general every process has its own.

Why do we need paging?

Paging is used for faster access to data. When a program needs a page, it is available in the main memory as the OS copies a certain number of pages from your storage device to main memory. Paging allows the physical address space of a process to be noncontiguous.

Can two processes share a page table?

The page table maps virtual addresses to physical memory addresses. Each process has its own page table in the kernel. No, all threads of a process share the same page table. The point of having threads is to be able to have multiple tasks operating on the same memory.

What is difference between page and frame?

A page (or memory page, or virtual page, or logical page) is a fixed-length contiguous block of virtual memory. A frame (or memory frame, or physical page, or page frame) is a fixed-length block of RAM (ie. physical memory, it exists – as in “physical”.