Re: [RFC] gro: Is it ok to share a single napi from several devs ?

David Miller
2010-08-28T22:33:39Z

From: Stephen Hemminger <shemminger@vyatta.com>
Date: Sat, 28 Aug 2010 15:31:24 -0700

> On Sat, 28 Aug 2010 14:41:30 -0700 (PDT)
> David Miller <davem@davemloft.net> wrote:
>
>> Since netpoll does similar things, this means both NAPI and netpoll
>> cannot function properly with SKY2's second port. It will only work
>> right on the first port.
>
> I knew netpoll was broken on second port.

Well, now we know that GRO is too :-)

If we wish to keep the one-to-one mapping of NAPI contexts to
interrupt sources, what we can do is provide some kind of "dev list".

The other option is to register two NAPI contexts and schedule them
both on an interrupt.

But in both cases, detecting the end of polling, and thus when to turn
the interrupts back on, is non-trivial.

I really don't like either solution, therefore, so I'll try to brain
storm on this a bit more.