Linux VM Notes
Fundamentals - Overview of virtual memory concepts without referencing any actual code or making assumptions about prior knowledge.
Process Address Space - Discussion about virtual memory address space for processes - managing VMAs, process data structure construction/destruction, file/device-backed memory regions, page faulting, demand allocation, COW pages, copying to/from userland.
Out of Memory Killer - Discussion about overcommit and how the OOM killer selects and kills victims.
Process Autopsy - Examining the memory allocation performed by the kernel for a simple userland application.
This repo contains my notes on the linux 4.6 VM subsystem. I don't make any claim to their quality or usefulness. They are an ongoing project and as such are a constant work in progress.
This work first originated from the notes I took from the excellent Understanding the Linux Virtual Memory Manager by Mel Gorman which, while great, targets the 2.4.22 kernel (released in 2003.) The obvious next stage of study was to take notes for a recent kernel, which is what these notes are!
I am specifically targeting the 4.6 kernel since it was the mainline version at the time of writing and should remain a sane and stable basis for notes and hacks for the foreseeable future. I may update to newer kernel versions over time depending on whether it makes sense to do so (and if I succeed at this project of course!)
Speaking of hacks
linux-vm-notes's sister repo, linux-vm-hacks, is
where I'm putting exploratory code and patches relating to my exploration of the
These notes are licensed under Creative Commons BY-NC-SA.