Re: [PATCH 1/1] ice: Change assigning method of the CPU affinity masks

[Yury Norov]

On Wed, Feb 08, 2023 at 04:39:05PM +0100, Pawel Chmielewski wrote:
> With the introduction of sched_numa_hop_mask() and
> for_each_numa_hop_mask(), the affinity masks for queue vectors can be
> conveniently set by preferring the CPUs that are closest to the NUMA node
> of the parent PCI device.
> 
> Signed-off-by: Pawel Chmielewski <pawel.chmielewski@xxxxxxxxx>
> ---
>  drivers/net/ethernet/intel/ice/ice_base.c | 17 ++++++++++++++---
>  1 file changed, 14 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/net/ethernet/intel/ice/ice_base.c b/drivers/net/ethernet/intel/ice/ice_base.c
> index e864634d66bc..fd3550d15c9e 100644
> --- a/drivers/net/ethernet/intel/ice/ice_base.c
> +++ b/drivers/net/ethernet/intel/ice/ice_base.c
> @@ -122,8 +122,6 @@ static int ice_vsi_alloc_q_vector(struct ice_vsi *vsi, u16 v_idx)
>  	if (vsi->type == ICE_VSI_VF)
>  		goto out;
>  	/* only set affinity_mask if the CPU is online */
> -	if (cpu_online(v_idx))
> -		cpumask_set_cpu(v_idx, &q_vector->affinity_mask);
>  
>  	/* This will not be called in the driver load path because the netdev
>  	 * will not be created yet. All other cases with register the NAPI
> @@ -659,8 +657,10 @@ int ice_vsi_wait_one_rx_ring(struct ice_vsi *vsi, bool ena, u16 rxq_idx)
>   */
>  int ice_vsi_alloc_q_vectors(struct ice_vsi *vsi)
>  {
> +	cpumask_t *aff_mask, *last_aff_mask = cpu_none_mask;
>  	struct device *dev = ice_pf_to_dev(vsi->back);
> -	u16 v_idx;
> +	int numa_node = dev->numa_node;
> +	u16 v_idx, cpu = 0;
>  	int err;
>  
>  	if (vsi->q_vectors[0]) {
> @@ -674,6 +674,17 @@ int ice_vsi_alloc_q_vectors(struct ice_vsi *vsi)
>  			goto err_out;
>  	}
>  
> +	v_idx = 0;
> +	for_each_numa_hop_mask(aff_mask, numa_node) {
> +		for_each_cpu_andnot(cpu, aff_mask, last_aff_mask)
> +			if (v_idx < vsi->num_q_vectors) {
> +				if (cpu_online(cpu))
> +					cpumask_set_cpu(cpu, &vsi->q_vectors[v_idx]->affinity_mask);
> +				v_idx++;
> +			}
                        
                        else
                                goto out;

> +		last_aff_mask = aff_mask;
> +	}
> +
        out:

>  	return 0;
>  
>  err_out:
> -- 
> 2.37.3

Would it make sense to increment v_idx only if matched CPU is online?
It will create a less sparse array of vectors...

Thanks,
Yury