• Virtual memory layout - x86-64 page table structure, virtual memory address space and conversion between physical and virtual memory.

• Physical page allocation - NUMA nodes, zones, and the physical page (buddy) allocator.

• Memory reclaim - Memory reclaim, compaction and OOM - i.e. how the kernel finds more memory when zones drop below low and minimum thresholds.

This is a set of notes on the linux memory management subsystem.

They assume an x86-64 architecture and all architecture-specific references to kernel code will reference x64-64 specific data structures and code.

Links to actual code will be taken from the current tip (permalinked via github) at circa-5.10. I may try to stabilise this at a specific release at some point but can't guarantee that at the moment.

These notes, unlike my originals, will make little to no effort to explain absolutely basic concepts, but rather assume that the reader understands or can research these kinds of things.