Re: [patch 21/30] net/mlx4: Use effective interrupt affinity

[Tariq Toukan <ttoukan.linux@xxxxxxxxx>]

On 12/10/2020 9:25 PM, Thomas Gleixner wrote:
> Using the interrupt affinity mask for checking locality is not really
> working well on architectures which support effective affinity masks.
>
> The affinity mask is either the system wide default or set by user space,
> but the architecture can or even must reduce the mask to the effective set,
> which means that checking the affinity mask itself does not really tell
> about the actual target CPUs.
>
> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: Tariq Toukan <tariqt@xxxxxxxxxx>
> Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
> Cc: Jakub Kicinski <kuba@xxxxxxxxxx>
> Cc: netdev@xxxxxxxxxxxxxxx
> Cc: linux-rdma@xxxxxxxxxxxxxxx
> ---
>   drivers/net/ethernet/mellanox/mlx4/en_cq.c |    2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> --- a/drivers/net/ethernet/mellanox/mlx4/en_cq.c
> +++ b/drivers/net/ethernet/mellanox/mlx4/en_cq.c
> @@ -117,7 +117,7 @@ int mlx4_en_activate_cq(struct mlx4_en_p
>                         assigned_eq = true;
>                 }
>                 irq = mlx4_eq_get_irq(mdev->dev, cq->vector);
> -               cq->aff_mask = irq_get_affinity_mask(irq);
> +               cq->aff_mask = irq_get_effective_affinity_mask(irq);
>         } else {
>                 /* For TX we use the same irq per
>                 ring we assigned for the RX    */
Reviewed-by: Tariq Toukan <tariqt@xxxxxxxxxx>

Thanks.