Interrupts: The Hidden World of Linux Performance
summary
Low CPU can hide thousands-per-second hardware interrupts that repeatedly steal the CPU and cause high latency and jitter; hard IRQs run immediately and defer work to soft IRQs or a high-priority kernel thread, affecting scheduling and real‑time responsiveness. Use top and /proc/interrupts to spot interrupt-heavy devices. Reduce interrupts by batching IO (write ~4KB chunks, coalesce network requests). For extreme loads or millions of packets/sec attacks, bypass the kernel with XDP (eBPF) to drop or process packets at the driver and avoid the main network stack.
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