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

[Parav Pandit <parav@nvidia.com>]

> From: Alvaro Karsz <alvaro.karsz@solid-run.com>
> Sent: Wednesday, February 8, 2023 5:36 PM
> 
> > > From: Alvaro Karsz <alvaro.karsz@solid-run.com>
> > > Sent: Wednesday, February 8, 2023 4:56 PM
> >
> > > > Alvaro,
> > > > Do you know if any software used it? Can you get some real data?
> > >
> > > I implemented this feature in our DPU, so at least 1 vendor is using
> > > this feature
> >
> > But which software (virtio net driver) in which OS is using this?
> 
> Sorry, I'm not sure I understand your question.
> 
> The feature is implemented in the linux kernel

Ok. so, there is sw using it. This global feature bit stays.

> > How does a driver disable all queues or reset all queues? -> One by one.
> > So if user want to change for all TXQ, sw can do it one by one by iterating TXQ
> vqns.
> 
> Yes, but resetting the queues doesn't require a control command.
> If a server has 64K queues, and a user wants to set all coalescing parameters to
> X (maybe with ethtool), it will generate 64K control commands..
He he. What an example.
64K control cmds. 64 register writes and poll. All same from sw pov.

The conclusion is there is sw using the feature bit defined in spec 1.3. Discussion ends.
I wish you pointed to this sw way earlier in the discussion.

Please proceed with the new feature bit and new command.