IRQ Affinity Tuning: Spread Network and Storage Interrupts

Linux lands most interrupts on CPU0 by default, leaving one core saturated while others idle and total throughput capped.

Interrupts defaulting to CPU0 is the trap

• Inspect: cat /proc/interrupts shows which core each IRQ lands on — watch NIC and storage controllers;
• Pin them: set /proc/irq//smp_affinity to spread NIC interrupts across the A76 cores;
• Pair with RPS/RFS: enable RSS on multi-queue NICs; on single-queue NICs RPS spreads softirqs with similar benefit.

For forwarding-heavy devices like routers and gateways, IRQ affinity tuning often pays more than a higher-clocked chip.

Related products: RT28 industrial router, RK3588 Mini PC. Datasheets, firmware and SDKs are free at the Hugsun Documentation Center; for selection advice or volume pricing, talk to us.