Due to the NAPI infrastructure, the accounting for interrupts generated by network driver is problematic: under low load the interrupt number is proportional to network traffic, but the more the network load increases the more the interrupts generated by the NICS are mitigated in software. Under very high network load is common that no interrupt at all is generated.

As a consequence, actions taken by irqbalance based on NIC interrupt numbers accounting are more often then not incorrect, especially in the most relevant scenarios, when the network load is high.

The proposed solution is limiting irqbalance to spread the NIC IRQs on the available CPUs and then leave the IRQ alone.