The purpose of irqbalance is to distribute hardware interrupts across processors on a multiprocessor system in order to increase performance.
exact IRQ affinity hint is applied unilaterally and never violated.
subset IRQ is balanced, but the assigned object will be a subset of the affinity hint.
ignore IRQ affinity hint value is completely ignored.
The default value for hintpolicy is ignore.
The default value for deepestcache is 2.