Page Fault Control Flow

With all of this knowledge in place, we can now roughly sketch the complete control flow of memory access. In other words, when somebody asks you “what happens when a program fetches some data from memory?”, you should have a pretty good idea of all the different possibilities. See the control flow in the snippets provided in this lesson for more details; the first snippet shows what the hardware does during translation and the second, what the OS does upon a page fault.

Hardware control flow

From the hardware control flow diagram in the snippet below, notice that there are now three important cases to understand when a TLB miss occurs.