Search results for "Spinlocks"

Debugging Linux Kernel Freezes: An eBPF Spinlock Saga

This article details the journey of debugging mysterious system freezes caused by eBPF programs in the Linux kernel. We uncovered an issue where an NMI-driven eBPF sampling program would self-deadlock by attempting to acquire a spinlock already held by another eBPF program on the same CPU, leading to 250ms kernel timeouts. The analysis highlights the complexities of spinlocks, NMIs, and cache coherence in kernel development.