Re: [PATCH v2 net] r8169: fix NAPI handling under high load

[Eric Dumazet]

On 10/18/2018 03:59 PM, Francois Romieu wrote:
> Eric Dumazet <eric.duma...@gmail.com> :
> [...]
>> One has to wonder why rtl8169_poll(), which might be called in a loop under 
>> DOS,
>> has to call rtl_ack_events() ?
> 
> So as to cover a wider temporal range before any event can trigger an
> extra irq. I was more worried about irq cost than about IO cost (and
> I still am).
> 
Normally the IRQ would not be enabled under DOS.

Only when a poll would receive less packets than the budget
the following would normally allow the device to send another IRQ

if (work_done < budget) {
    napi_complete_done(napi, work_done);
    rtl_irq_enable(tp, enable_mask);
    mmiowb();
}