This commit allows spreading IO IRQs over different CPUs through sysctl.
Two sysctl nodes are introduced:
1- base_cpu: servers as the first CPU to which the first IO IRQ will be bound.
2- cpu_stride: sets the distance between every two CPUs to which every two consecutive IO IRQs are bound.
For example for doing the following IO IRQs / CPU binding:
IRQ idx | CPU
----------------
1 | 0
2 | 2
3 | 4
4 | 6
Run the following commands:
sysctl dev.ena.<device index>.irq_affinity.base_cpu=0
sysctl dev.ena.<device_index>.irq_affinity.cpu_stride=2
MFC after: 2 weeks
Sponsored by: Amazon, Inc.