PostgreSQL and Linux Kernel interactions | POSETTE: An Event for Postgres 2025

Video of a conference talk about PostgreSQL and Linux Kernel interactions. PostgreSQL interacts with the Linux kernel at multiple points during its runtime. This talk will provide an in-depth examination of these interactions. The session will delve into kernel internals for operations such as file reading and writing, buffer cache interactions, process initialization, memory management, among others. Attendees will also gain foundational knowledge on identifying and troubleshooting bottlenecks within these interactions using tools like strace, perf, fincore, and /proc entries. The talk will conclude with insights into ongoing efforts to leverage more advanced and efficient kernel facilities, demonstrated through examples such as copy_file_range (to enhance file data handling) and io_uring (for asynchronous IO). Krishnakumar “KK” Ravi started his professional life with porting Linux to embedded boards used in firewalls, electric networks, etc. Spanning two decades of industry experience, KK has spent time solving challenges, building products and features in areas such as High Performance Computing (HPC), Scalable filesystems and Storage. He came to Microsoft as part of Storsimple (a hybrid cloud storage product) acquisition and stayed around working on the intersection of edge and the cloud and spent time in the Kubernetes space before moving to databases. After being part of the journey to build a growing PostgreSQL service on Azure, he joined as Engineering Manager for committer and contributor teams focused on open source PostgreSQL. ► Video bookmarks: ⏩ 00:00 Introduction ⏩ 02:45 What are you going to learn? ⏩ 05:32 Strace basics ⏩ 07:20 Interactions with kernel (high level view) ⏩ 09:27 System call examples ⏩ 13:28 Process management ⏩ 15:22 Memory, Signals ⏩ 20:03 Buffered & Direct I/O ⏩ 24:42 With and without I/O  Combining (PG16 & PG17) ⏩ 25:33 Prefetch, Misc system calls, New usages 📕 Everything you need to know about POSETTE: A