Linux Page Cache for SRE

SRE deep dive into Linux Page Cache # Last updated: Oct 2025 Contents Prepare environment for experiments Essential Page Cache theory Page Cache and basic file operations Page Cache eviction and page reclaim More about mmap() file access cgroup v2 and Page Cache How much memory my program uses or the tale of working set size Direct IO (DIO) Advanced Page Cache observability and troubleshooting tools In this series of articles, I would like to talk about Linux Page Cache. I believe that the following knowledge of the theory and tools is essential and crucial for every SRE. This understanding can help both in usual and routine everyday DevOps-like tasks and in emergency debugging and firefighting. Page Cache is often left unattended, and its better understanding leads to the following: