On Monday 04 February 2013, Linus Walleij wrote: > So I think the above concerns are moot. The callback we can > set on cookies is entirely optional, and it's even implemented by > each DMA engine, and some may not even support it but require > polling, and then it won't even be implemented by the driver. Just to ensure that everybody is talking about the same thing here: Is it just the callback that is optional, or also the interrupt coming from the hardware? With NAPI, you want to avoid both, since getting an interrupt for every packet adds noticeable overhead, but you still want to be able to tell the hardware that you are fed up with polling and would like to get an interrupt again when the next data arrives (ideally, after either a little time has passed after the next packet, or a specific number of packets has arrived). Arnd -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html