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Date: Thu, 30 May 2024 17:11:28 -0700
From: Jakub Kicinski <kuba@kernel.org>
To: Joe Damato <jdamato@fastly.com>
Cc: linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
 nalramli@fastly.com, "David S. Miller" <davem@davemloft.net>, Eric Dumazet
 <edumazet@google.com>, Leon Romanovsky <leon@kernel.org>,
 linux-rdma@vger.kernel.org (open list:MELLANOX MLX5 core VPI driver), Paolo
 Abeni <pabeni@redhat.com>, Richard Cochran <richardcochran@gmail.com>,
 Saeed Mahameed <saeedm@nvidia.com>, Tariq Toukan <tariqt@nvidia.com>
Subject: Re: [RFC net-next v3 0/2] mlx5: Add netdev-genl queue stats
Message-ID: <20240530171128.35bd0ee2@kernel.org>
In-Reply-To: <20240529031628.324117-1-jdamato@fastly.com>
References: <20240529031628.324117-1-jdamato@fastly.com>
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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?

> 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.