[RFC,net-next,2/2] idpf: use napi's irq affinity

Commit Message

Ahmed Zaki Dec. 6, 2024, 12:12 a.m. UTC

Delete the driver CPU affinity info and use the core's napi config
instead.

Cc: [e-mail]
Signed-off-by: Ahmed Zaki <[e-mail]>
---
 drivers/net/ethernet/intel/idpf/idpf_txrx.c | 18 ++++--------------
 drivers/net/ethernet/intel/idpf/idpf_txrx.h |  6 ++----
 2 files changed, 6 insertions(+), 18 deletions(-)

Comments

Paul Menzel Dec. 6, 2024, 8:29 a.m. UTC | #1

Dear Ahmed,


Thank you for your patch.

Am 06.12.24 um 01:12 schrieb Ahmed Zaki:
> Delete the driver CPU affinity info and use the core's napi config
> instead.

Excuse my ignorance, but could you please state why? (Is the core’s napi 
config the successor?)

> Cc: [e-mail]
> Signed-off-by: Ahmed Zaki <[e-mail]>
> ---
>   drivers/net/ethernet/intel/idpf/idpf_txrx.c | 18 ++++--------------
>   drivers/net/ethernet/intel/idpf/idpf_txrx.h |  6 ++----
>   2 files changed, 6 insertions(+), 18 deletions(-)

[…]


Kind regards,

Paul

Ahmed Zaki Dec. 6, 2024, 5:58 p.m. UTC | #2

On 2024-12-06 1:29 a.m., Paul Menzel wrote:
> Dear Ahmed,
> 
> 
> Thank you for your patch.
> 
> Am 06.12.24 um 01:12 schrieb Ahmed Zaki:
>> Delete the driver CPU affinity info and use the core's napi config
>> instead.
> 
> Excuse my ignorance, but could you please state why? (Is the core’s napi 
> config the successor?)
> 

Hi Paul

I am not sure I understand what you mean by "successor"!

This patch is an example on how the new "napi_config->affinity_mask" 
defined in patch 1/2 of the series could be used instead of keeping the 
affinity mask in the driver.

It is kind of code cleanup since the task can be done in the core for 
all drivers.

Patch

diff --git a/drivers/net/ethernet/intel/idpf/idpf_txrx.c b/drivers/net/ethernet/intel/idpf/idpf_txrx.c
index da2a5becf62f..ffa75a98cdc6 100644
--- a/drivers/net/ethernet/intel/idpf/idpf_txrx.c
+++ b/drivers/net/ethernet/intel/idpf/idpf_txrx.c
@@ -3553,8 +3553,6 @@  void idpf_vport_intr_rel(struct idpf_vport *vport)
 		q_vector->tx = NULL;
 		kfree(q_vector->rx);
 		q_vector->rx = NULL;
-
-		free_cpumask_var(q_vector->affinity_mask);
 	}
 
 	kfree(vport->q_vectors);
@@ -3581,8 +3579,6 @@  static void idpf_vport_intr_rel_irq(struct idpf_vport *vport)
 		vidx = vport->q_vector_idxs[vector];
 		irq_num = adapter->msix_entries[vidx].vector;
 
-		/* clear the affinity_mask in the IRQ descriptor */
-		irq_set_affinity_hint(irq_num, NULL);
 		kfree(free_irq(irq_num, q_vector));
 	}
 }
@@ -3761,8 +3757,6 @@  static int idpf_vport_intr_req_irq(struct idpf_vport *vport)
 				   "Request_irq failed, error: %d\n", err);
 			goto free_q_irqs;
 		}
-		/* assign the mask for this irq */
-		irq_set_affinity_hint(irq_num, q_vector->affinity_mask);
 	}
 
 	return 0;
@@ -4183,12 +4177,11 @@  static void idpf_vport_intr_napi_add_all(struct idpf_vport *vport)
 
 	for (v_idx = 0; v_idx < vport->num_q_vectors; v_idx++) {
 		struct idpf_q_vector *q_vector = &vport->q_vectors[v_idx];
+		int irq_num = vport->adapter->msix_entries[v_idx].vector;
 
-		netif_napi_add(vport->netdev, &q_vector->napi, napi_poll);
-
-		/* only set affinity_mask if the CPU is online */
-		if (cpu_online(v_idx))
-			cpumask_set_cpu(v_idx, q_vector->affinity_mask);
+		netif_napi_add_config(vport->netdev, &q_vector->napi,
+				      napi_poll, v_idx);
+		netif_napi_set_irq(&q_vector->napi, irq_num);
 	}
 }
 
@@ -4232,9 +4225,6 @@  int idpf_vport_intr_alloc(struct idpf_vport *vport)
 		q_vector->rx_intr_mode = IDPF_ITR_DYNAMIC;
 		q_vector->rx_itr_idx = VIRTCHNL2_ITR_IDX_0;
 
-		if (!zalloc_cpumask_var(&q_vector->affinity_mask, GFP_KERNEL))
-			goto error;
-
 		q_vector->tx = kcalloc(txqs_per_vector, sizeof(*q_vector->tx),
 				       GFP_KERNEL);
 		if (!q_vector->tx)
diff --git a/drivers/net/ethernet/intel/idpf/idpf_txrx.h b/drivers/net/ethernet/intel/idpf/idpf_txrx.h
index 9c1fe84108ed..5efb3402b378 100644
--- a/drivers/net/ethernet/intel/idpf/idpf_txrx.h
+++ b/drivers/net/ethernet/intel/idpf/idpf_txrx.h
@@ -397,7 +397,6 @@  struct idpf_intr_reg {
  * @rx_intr_mode: Dynamic ITR or not
  * @rx_itr_idx: RX ITR index
  * @v_idx: Vector index
- * @affinity_mask: CPU affinity mask
  */
 struct idpf_q_vector {
 	__cacheline_group_begin_aligned(read_mostly);
@@ -434,13 +433,12 @@  struct idpf_q_vector {
 	__cacheline_group_begin_aligned(cold);
 	u16 v_idx;
 
-	cpumask_var_t affinity_mask;
 	__cacheline_group_end_aligned(cold);
 };
 libeth_cacheline_set_assert(struct idpf_q_vector, 112,
 			    24 + sizeof(struct napi_struct) +
 			    2 * sizeof(struct dim),
-			    8 + sizeof(cpumask_var_t));
+			    8);
 
 struct idpf_rx_queue_stats {
 	u64_stats_t packets;
@@ -934,7 +932,7 @@  static inline int idpf_q_vector_to_mem(const struct idpf_q_vector *q_vector)
 	if (!q_vector)
 		return NUMA_NO_NODE;
 
-	cpu = cpumask_first(q_vector->affinity_mask);
+	cpu = cpumask_first(&q_vector->napi.config->affinity_mask);
 
 	return cpu < nr_cpu_ids ? cpu_to_mem(cpu) : NUMA_NO_NODE;
 }