On 9/24/2023 7:05 PM, Yury Norov wrote:
> The function duplicates existing cpumask_local_spread(), and it's O(N),
> while cpumask_local_spread() implementation is based on bsearch, and
> thus is O(log n), so drop mlx5_cpumask_default_spread() and use generic
> cpumask_local_spread().
>
> Signed-off-by: Yury Norov <yury.norov@xxxxxxxxx>
> Signed-off-by: Yury Norov <ynorov@xxxxxxxxxx>
> ---
> drivers/net/ethernet/mellanox/mlx5/core/eq.c | 28 ++------------------
> 1 file changed, 2 insertions(+), 26 deletions(-)
>
> diff --git a/drivers/net/ethernet/mellanox/mlx5/core/eq.c b/drivers/net/ethernet/mellanox/mlx5/core/eq.c
> index ea0405e0a43f..bd9f857cc52d 100644
> --- a/drivers/net/ethernet/mellanox/mlx5/core/eq.c
> +++ b/drivers/net/ethernet/mellanox/mlx5/core/eq.c
> @@ -828,30 +828,6 @@ static void comp_irq_release_pci(struct mlx5_core_dev *dev, u16 vecidx)
> mlx5_irq_release_vector(irq);
> }
>
Reviewed-by: Jacob Keller <jacob.e.keller@xxxxxxxxx>
> -static int mlx5_cpumask_default_spread(int numa_node, int index)
> -{
> - const struct cpumask *prev = cpu_none_mask;
> - const struct cpumask *mask;
> - int found_cpu = 0;
> - int i = 0;
> - int cpu;
> -
> - rcu_read_lock();
> - for_each_numa_hop_mask(mask, numa_node) {
> - for_each_cpu_andnot(cpu, mask, prev) {
> - if (i++ == index) {
> - found_cpu = cpu;
> - goto spread_done;
> - }
> - }
> - prev = mask;
> - }
> -
> -spread_done:
> - rcu_read_unlock();
> - return found_cpu;
> -}
> -
> static struct cpu_rmap *mlx5_eq_table_get_pci_rmap(struct mlx5_core_dev *dev)
> {
> #ifdef CONFIG_RFS_ACCEL
> @@ -873,7 +849,7 @@ static int comp_irq_request_pci(struct mlx5_core_dev *dev, u16 vecidx)
> int cpu;
>
> rmap = mlx5_eq_table_get_pci_rmap(dev);
> - cpu = mlx5_cpumask_default_spread(dev->priv.numa_node, vecidx);
> + cpu = cpumask_local_spread(vecidx, dev->priv.numa_node);
> irq = mlx5_irq_request_vector(dev, cpu, vecidx, &rmap);
> if (IS_ERR(irq))
> return PTR_ERR(irq);
> @@ -1125,7 +1101,7 @@ int mlx5_comp_vector_get_cpu(struct mlx5_core_dev *dev, int vector)
> if (mask)
> cpu = cpumask_first(mask);
> else
> - cpu = mlx5_cpumask_default_spread(dev->priv.numa_node, vector);
> + cpu = cpumask_local_spread(vector, dev->priv.numa_node);
>
> return cpu;
> }
