TRANSCENDENT MEMORY BACKEND
This collection of modules is used to provide support for a subset of Transcendent Memory functionality over a character device. Transcendent Memory is a concept introduced in the Linux kernel around 2009, whose goal is to provide a pool of not directly addressable memory; that way, since every access to the pages in the pool require explicit calls to a backend, there is increased flexibility in the way we store the data (e.g. remotely), as well as in the way we represent them (e.g. the data could be compressed, as done by the zswap module).
The modules here include the character device used to expose the tmem functionality to userspace, the various backends that provide different kinds of functionality, as well as modules used to connect the tmem pool with services that make use of it in the kernel itself (i.e. frontswap; cleancache could also be implemented).