linux NAPI devices

linux NAPI devices

quoted from profession linux kernel architectures by Wolfgang Mauerer
page 764.

1. The first packet cases the network adapter to issue an IRQ. To prevent further packets from causing more IRQs, the driver turn off Rx IRQs for the adapters.

additionally, the adapters is placed on a poll list.

2. the kernel then polls the devices on the poll list as long as no further packets wait to be processed on the adapter.

3. Rx interrupts are re-enabled again.