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Date: Thu, 13 Jun 2024 15:12:00 -0700
From: Joe Damato <jdamato@fastly.com>
To: Jakub Kicinski <kuba@kernel.org>
Cc: Tariq Toukan <ttoukan.linux@gmail.com>, netdev@vger.kernel.org,
	linux-kernel@vger.kernel.org, nalramli@fastly.com,
	Saeed Mahameed <saeedm@nvidia.com>,
	Leon Romanovsky <leon@kernel.org>,
	"David S. Miller" <davem@davemloft.net>,
	Eric Dumazet <edumazet@google.com>, Paolo Abeni <pabeni@redhat.com>,
	Richard Cochran <richardcochran@gmail.com>,
	"open list:MELLANOX MLX5 core VPI driver" <linux-rdma@vger.kernel.org>,
	Tariq Toukan <tariqt@nvidia.com>
Subject: Re: [net-next v5 2/2] net/mlx5e: Add per queue netdev-genl stats
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	Jakub Kicinski <kuba@kernel.org>,
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	Saeed Mahameed <saeedm@nvidia.com>,
	Leon Romanovsky <leon@kernel.org>,
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	Eric Dumazet <edumazet@google.com>, Paolo Abeni <pabeni@redhat.com>,
	Richard Cochran <richardcochran@gmail.com>,
	"open list:MELLANOX MLX5 core VPI driver" <linux-rdma@vger.kernel.org>,
	Tariq Toukan <tariqt@nvidia.com>
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On Thu, Jun 13, 2024 at 02:58:17PM -0700, Jakub Kicinski wrote:
> On Thu, 13 Jun 2024 23:25:12 +0300 Tariq Toukan wrote:
> > > +		for (i = priv->channels.params.num_channels; i < priv->stats_nch; i++) {  
> > 
> > IIUC, per the current kernel implementation, the lower parts won't be 
> > completed in a loop over [0..real_num_rx_queues-1], as that loop is 
> > conditional, happening only if the queues are active.
> 
> Could you rephrase this? Is priv->channels.params.num_channels
> non-zero also when device is closed? I'm just guessing from 
> the code, TBH, I can't parse your reply :(

I don't mean to speak for Tariq (so my apologies Tariq), but I
suspect it may not be clear in which cases IFF_UP is checked and in
which cases get_base is called.

I tried to clear it up in my longer response with examples from
code.

If you have a moment could you take a look and let me know if I've
gotten it wrong in my explanation/walk through?