Open Source Summit India 2026

Efficient interrupt handling is at the heart of modern operating systems, enabling hardware devices to communicate seamlessly with the kernel. In the Linux ecosystem, the evolution from legacy line based interrupts to advanced mechanisms like Message Signaled Interrupts (MSI) and MSI X has significantly improved scalability, performance, and reliability. Yet, for many developers and practitioners, the inner workings of these mechanisms remain opaque.
This talk aims to demystify PCI interrupt handling in Linux, with a focus on MSI/MSI X. We will begin by revisiting the limitations of traditional interrupt models, then explore how MSI/MSI X leverage in band signaling to overcome them. Attendees will gain insights into:
• The architectural differences between legacy interrupts and MSI/MSI X.
• How the Linux kernel configures and manages these interrupts.
• Practical debugging techniques for PCI devices using MSI/MSI X.
• Real world performance implications in networking, storage, and virtualization workloads.