Subject: Re: [PATCH net-next V2 2/2] net/mlx5e: Improve remote NUMA preferences used for the IRQ affinity hints

From: Jakub Kicinski <[email-masked]>
Date: Mon, 18 Jul 2022 14:57:17 -0700

On Mon, 18 Jul 2022 22:49:21 +0300 Tariq Toukan wrote:
> >> @@ -830,8 +887,7 @@ static int comp_irqs_request(struct mlx5_core_dev *dev)
> >>   		ret = -ENOMEM;
> >>   		goto free_irqs;
> >>   	}
> >> -	for (i = 0; i < ncomp_eqs; i++)
> >> -		cpus[i] = cpumask_local_spread(i, dev->priv.numa_node);
> >> +	mlx5_set_eqs_cpus(dev, cpus, ncomp_eqs);  
> > 
> > So you change this for mlx5, what about the other users of
> > cpumask_local_spread() ?  
> 
> I took a look at the different netdev users.
> While some users have similar use case to ours (affinity hints), many 
> others use cpumask_local_spread in other flows (XPS setting, ring 
> allocations, etc..).
> 
> Moving them to use the newly exposed API needs some deeper dive into 
> their code, especially due to the possible undesired side-effects.
> 
> I prefer not to include these changes in my series for now, but probably 
> contribute it in a followup work.

I'd be great if you could pick any other driver and start creating 
the right APIs for it and mlx5. "Probably contribute followup work"
does not inspire confidence. And yes, I am being picky, I'm holding 
a grudge against mlx5 for not using netif_get_num_default_rss_queues().