Re: [virtio-dev] Re: [virtio-comment] Re: [PATCH] virtio-net: support per-queue coalescing moderation

["Michael S. Tsirkin" <mst@redhat.com>]

On Tue, Feb 07, 2023 at 04:56:06PM +0200, Alvaro Karsz wrote:
> > An example of a question is this: we have two RX queues say 1 and 2 each
> > with a distinct interrupt vector. coalescing is set to 10 packets.  Now
> > 9 packets arrive on queue 1 and 1 on queue 2. Do you expect an
> > interrupt? If yes which one - 1 or 2 or both?
> 
> Sorry, I wasn't clear enough.
> In this case, you should not issue an interrupt until one of the
> queues receives the 10'th packet.
> The counters are per queue, the coalescing parameters (usecs and
> max_packets) are global.
> 
> I agree that this should be mentioned in the spec, I missed it.

Right. So in my humble opinion, ability to configure parameters per
queue is not completely free, as this is doubling the memory requirements.
Sounds like a feature bit is somewhat justified. No?

-- 
MST