Interrupting an interrupt.

What this interrupt-handling interview question tests

This is an easy operating-systems question that probes whether you understand how kernels manage nested or concurrent interrupts. It's the kind of fundamentals check that appears in systems interviews, particularly at firms building trading infrastructure, market-data pipelines, or other latency-sensitive services where interrupt behaviour matters.

The question asks you to reason about the trade-offs between different kernel strategies when an interrupt arrives while the OS is already servicing another one. Strong answers distinguish between approaches like deferral, prioritization, disabling interrupts, and queueing—and recognize which techniques are actually viable under real constraints.

• Interrupt prioritization and masking
• Deferred work and interrupt disabling
• Interrupt queuing and context switching
• Kernel-level concurrency and race conditions