Page Replacement in Linux 2.4 Memory Management

While the virtual memory management in Linux 2.2 has decent performance for many workloads, it suffers from a number of problems. The first part of this paper contains a description of how the Linux 2.2 VMM works and an analysis of why it has bad behaviour in some situations. The way in which a lot of this behaviour has been fixed in the Linux 2.4 kernel is described in the second part of the paper. Due to Linux 2.4 being in a code freeze period while these improvements were implemented, only known-good solutions have been integrated. A lot of the ideas used are derived from principles used in other operating systems, mostly because we have certainty that they work and a good understanding of why, making them suitable for integration into the Linux codebase during a code freeze.