Demand Paging: What Happens When Linux Handles a Page Fault

Welcome back to the video series on virtual memory based on my article on the same topic. It is also available in ebook format on Gumroad (pdf/epub) and Amazon Kindle, if you prefer those formats.Buy PDF/EpubGet Kindle EditionSo far in this video series we have covered the foundational pieces behind virtual memory:What is virtual memory and why do we need itSize of the virtual address space of a processAddress space of a processStructure of page tables and how page table walks workWhat is inside a page table entrySize of a physical addressFrom here on, the next set of topics is going to be more advanced and important for debugging memory issues in real-world systems. The topic of this video is demand paging, which is central to how memory allocation works inside the kernel.Demand paging simply means that when you ask the kernel for more memory, it reserves a virtual address range for you but does not perform physical memory allocation until you actually need it. This can lead to…