Re: [PATCH net-next v2 2/5] page_pool: Add per-queue statistics.

[Jakub Kicinski <kuba@kernel.org>]

On Fri, 7 Mar 2025 17:50:46 +0100 Sebastian Andrzej Siewior wrote:
> On 2025-03-07 08:11:35 [-0800], Jakub Kicinski wrote:
> > On Fri,  7 Mar 2025 12:57:19 +0100 Sebastian Andrzej Siewior wrote:  
> > > The mlx5 driver supports per-channel statistics. To make support generic
> > > it is required to have a template to fill the individual channel/ queue.
> > > 
> > > Provide page_pool_ethtool_stats_get_strings_mq() to fill the strings for
> > > multiple queue.  
> > 
> > Sorry to say this is useless as a common helper, you should move it 
> > to mlx5.
> > 
> > The page pool stats have a standard interface, they are exposed over
> > netlink. If my grep-foo isn't failing me no driver uses the exact
> > strings mlx5 uses. "New drivers" are not supposed to add these stats
> > to ethtool -S, and should just steer users towards the netlink stats.
> > 
> > IOW mlx5 is and will remain the only user of this helper forever.  
> 
> Okay, so per-runqueue stats is not something other/ new drivers are
> interested in?
> The strings are the same, except for the rx%d_ prefix, but yes this
> makes it unique.
> The mlx5 folks seem to be the only one interested in this. The veth
> driver for instance iterates over real_num_rx_queues and adds all
> per-queue stats into one counter. It could also expose this per-runqueue
> as it does with xdp_packets for instance. But then it uses the
> rx_queue_%d prefix…

What I'm saying is they are already available per queue, via netlink,
with no driver work necessary. See tools/net/ynl/samples/page-pool.c
The mlx5 stats predate the standard interface.

> I don't care, I just intended to provide some generic facility so we
> don't have every driver rolling its own thing. I have no problem to move
> this to the mlx5 driver.

Thanks, and sorry for not catching the conversation earlier.