Linux 7.0 introduced a preemption regression that caused PostgreSQL throughput to drop by 50% on high-core systems. The issue was traced to excessive CPU time spent in s_lock functions due to changed scheduling behavior. AWS engineer Salvatore Dipietro identified and patched the problem affecting 96-vCPU Graviton4 machines.
Background
Linux kernel scheduling changes can significantly impact database performance on high-core systems. PostgreSQL relies on efficient memory management and locking mechanisms that are sensitive to OS scheduling behavior.
- Source
- Lobsters
- Published
- Apr 30, 2026 at 04:30 AM
- Score
- 8.0 / 10