Linux memory management subsystem is responsible, as the name implies, for managing the memory in the system. This includes implemnetation of virtual memory and demand paging, memory allocation both for kernel internal structures and user space programms, mapping of files into processes address space and many other cool things.
Linux memory management is a complex system with many configurable
settings. Most of these settings are available via
filesystem and can be quired and adjusted using
sysctl. These APIs
are described in Documentation/sysctl/vm.txt and in man 5 proc.
Linux memory management has its own jargon and if you are not yet familiar with it, consider reading Documentation/admin-guide/mm/concepts.rst.
Here we document in detail how to interact with various mechanisms in the Linux memory management.