Re: [Patch v2 3/3] net: Restrict receive packets queuing to housekeeping CPUs

[Peter Zijlstra]

On Mon, Jun 22, 2020 at 07:45:10PM -0400, Nitesh Narayan Lal wrote:
> @@ -756,6 +757,13 @@ static ssize_t store_rps_map(struct netdev_rx_queue *queue,
>  		return err;
>  	}
>  
> +	hk_flags = HK_FLAG_DOMAIN | HK_FLAG_WQ;
> +	cpumask_and(mask, mask, housekeeping_cpumask(hk_flags));
> +	if (cpumask_weight(mask) == 0) {

We have cpumask_empty() for that, which is a much more efficient way of
testing the same.

> +		free_cpumask_var(mask);
> +		return -EINVAL;
> +	}
> +
>  	map = kzalloc(max_t(unsigned int,
>  			    RPS_MAP_SIZE(cpumask_weight(mask)), L1_CACHE_BYTES),
>  		      GFP_KERNEL);
> -- 
> 2.18.4
>