Re: [RFC net-next v3 0/2] mlx5: Add netdev-genl queue stats

Joe Damato
2024-05-31T00:15:28Z

On Thu, May 30, 2024 at 05:11:28PM -0700, Jakub Kicinski wrote:
> On Wed, 29 May 2024 03:16:25 +0000 Joe Damato wrote:
> > Worth noting that Tariq suggested I also export HTB/QOS stats in
> > mlx5e_get_base_stats.
>
> Why to base, and not report them as queue stats?
>
> Judging by mlx5e_update_tx_netdev_queues() calls sprinkled in
> ../mlx5/core/en/htb.c it seems that the driver will update the
> real_num_tx_queues accordingly. And from mlx5e_qid_from_qos()
> it seems like the inverse calculation is:
>
> i - (chs->params.num_channels + is_ptp)*mlx5e_get_dcb_num_tc(&chs->params)
>
> But really, isn't it enough to use priv->txq2sq[i] for the active
> queues, and not active ones you've already covered?

This is what I proposed in the thread for the v2, but Tariq
suggested a different approach he liked more, please see this
message for more details:

https://lore.kernel.org/netdev/68225941-f3c3-4335-8f3d-edee43f59033@gmail.com/

I attempted to implement option 1 as he described in his message.

> > I am open to doing this, but I think if I were to do that, HTB/QOS queue
> > stats should also be exported by rtnl so that the script above will
> > continue to show that the output is correct.
> >
> > I'd like to propose: adding HTB/QOS to both rtnl *and* the netdev-genl
> > code together at the same time, but a later time, separate from this
> > change.
>
> Hm, are HTB queues really not counted in rtnl? That'd be pretty wrong.

As far as I can tell (and I could be wrong) I didn't see them
included in the rtnl stats, but I'll take another look now.