2020-12-10 19:49:39

by Thomas Gleixner

Subject: [patch 23/30] net/mlx5: Use effective interrupt affinity

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 <[email protected]>
Cc: Saeed Mahameed <[email protected]>
Cc: Leon Romanovsky <[email protected]>
Cc: "David S. Miller" <[email protected]>
Cc: Jakub Kicinski <[email protected]>
Cc: [email protected]
Cc: [email protected]
---
drivers/net/ethernet/mellanox/mlx5/core/en_main.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
@@ -1998,7 +1998,7 @@ static int mlx5e_open_channel(struct mlx
c->num_tc = params->num_tc;
c->xdp = !!params->xdp_prog;
c->stats = &priv->channel_stats[ix].ch;
- c->aff_mask = irq_get_affinity_mask(irq);
+ c->aff_mask = irq_get_effective_affinity_mask(irq);
c->lag_port = mlx5e_enumerate_lag_port(priv->mdev, ix);

netif_napi_add(netdev, &c->napi, mlx5e_napi_poll, 64);

2020-12-13 15:32:01

by tip-bot2 for Alexey Makhalov

Subject: [tip: irq/core] net/mlx5: Use effective interrupt affinity

The following commit has been merged into the irq/core branch of tip:

Commit-ID: ca00c76aa8acf5a7563dd9f5020f9c6dc9a0577d
Gitweb: https://git.kernel.org/tip/ca00c76aa8acf5a7563dd9f5020f9c6dc9a0577d
Author: Thomas Gleixner <[email protected]>
AuthorDate: Thu, 10 Dec 2020 20:25:59 +01:00
Committer: Thomas Gleixner <[email protected]>
CommitterDate: Sat, 12 Dec 2020 12:59:06 +01:00

net/mlx5: Use effective interrupt affinity

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 <[email protected]>
Cc: Saeed Mahameed <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

---
drivers/net/ethernet/mellanox/mlx5/core/en_main.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
index 0e19b3c..dad9bd8 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
@@ -1998,7 +1998,7 @@ static int mlx5e_open_channel(struct mlx5e_priv *priv, int ix,
c->num_tc = params->num_tc;
c->xdp = !!params->xdp_prog;
c->stats = &priv->channel_stats[ix].ch;
- c->aff_mask = irq_get_affinity_mask(irq);
+ c->aff_mask = irq_get_effective_affinity_mask(irq);
c->lag_port = mlx5e_enumerate_lag_port(priv->mdev, ix);

netif_napi_add(netdev, &c->napi, mlx5e_napi_poll, 64);

2020-12-13 18:44:10

by Tariq Toukan

Subject: Re: [patch 23/30] net/mlx5: Use effective interrupt affinity

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 <[email protected]>
> Cc: Saeed Mahameed <[email protected]>
> Cc: Leon Romanovsky <[email protected]>
> Cc: "David S. Miller" <[email protected]>
> Cc: Jakub Kicinski <[email protected]>
> Cc: [email protected]
> Cc: [email protected]
> ---
> drivers/net/ethernet/mellanox/mlx5/core/en_main.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> --- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
> +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
> @@ -1998,7 +1998,7 @@ static int mlx5e_open_channel(struct mlx
> c->num_tc = params->num_tc;
> c->xdp = !!params->xdp_prog;
> c->stats = &priv->channel_stats[ix].ch;
> - c->aff_mask = irq_get_affinity_mask(irq);
> + c->aff_mask = irq_get_effective_affinity_mask(irq);
> c->lag_port = mlx5e_enumerate_lag_port(priv->mdev, ix);
>
> netif_napi_add(netdev, &c->napi, mlx5e_napi_poll, 64);
>

Reviewed-by: Tariq Toukan <[email protected]>

Thanks.

2020-12-14 21:03:52

by Saeed Mahameed

Subject: Re: [patch 23/30] net/mlx5: Use effective interrupt affinity

On Thu, 2020-12-10 at 20:25 +0100, 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 <[email protected]>
> Cc: Saeed Mahameed <[email protected]>
> Cc: Leon Romanovsky <[email protected]>
> Cc: "David S. Miller" <[email protected]>
> Cc: Jakub Kicinski <[email protected]>
> Cc: [email protected]
> Cc: [email protected]
>

Acked-by: Saeed Mahameed <[email protected]>