Re: [PATCH net-next 07/16] idpf: link NAPIs to queues

[Alexander Lobakin]

From: Maciej Fijalkowski <maciej.fijalkowski@xxxxxxxxx>
Date: Fri, 7 Mar 2025 11:51:18 +0100

> On Wed, Mar 05, 2025 at 05:21:23PM +0100, Alexander Lobakin wrote:
>> Add the missing linking of NAPIs to netdev queues when enabling
>> interrupt vectors in order to support NAPI configuration and
>> interfaces requiring get_rx_queue()->napi to be set (like XSk
>> busy polling).
>>
>> Signed-off-by: Alexander Lobakin <aleksander.lobakin@xxxxxxxxx>
>> ---
>>  drivers/net/ethernet/intel/idpf/idpf_txrx.c | 30 +++++++++++++++++++++
>>  1 file changed, 30 insertions(+)
>>
>> diff --git a/drivers/net/ethernet/intel/idpf/idpf_txrx.c b/drivers/net/ethernet/intel/idpf/idpf_txrx.c
>> index 2f221c0abad8..a3f6e8cff7a0 100644
>> --- a/drivers/net/ethernet/intel/idpf/idpf_txrx.c
>> +++ b/drivers/net/ethernet/intel/idpf/idpf_txrx.c
>> @@ -3560,8 +3560,11 @@ void idpf_vport_intr_rel(struct idpf_vport *vport)
>>  static void idpf_vport_intr_rel_irq(struct idpf_vport *vport)
>>  {
>>  	struct idpf_adapter *adapter = vport->adapter;
>> +	bool unlock;
>>  	int vector;
>>  
>> +	unlock = rtnl_trylock();
>> +
>>  	for (vector = 0; vector < vport->num_q_vectors; vector++) {
>>  		struct idpf_q_vector *q_vector = &vport->q_vectors[vector];
>>  		int irq_num, vidx;
>> @@ -3573,8 +3576,23 @@ static void idpf_vport_intr_rel_irq(struct idpf_vport *vport)
>>  		vidx = vport->q_vector_idxs[vector];
>>  		irq_num = adapter->msix_entries[vidx].vector;
>>  
>> +		for (u32 i = 0; i < q_vector->num_rxq; i++)
>> +			netif_queue_set_napi(vport->netdev,
>> +					     q_vector->rx[i]->idx,
>> +					     NETDEV_QUEUE_TYPE_RX,
>> +					     NULL);
>> +
>> +		for (u32 i = 0; i < q_vector->num_txq; i++)
>> +			netif_queue_set_napi(vport->netdev,
>> +					     q_vector->tx[i]->idx,
>> +					     NETDEV_QUEUE_TYPE_TX,
>> +					     NULL);
>> +
> 
> maybe we could have a wrapper for this?
> 
> static void idpf_q_set_napi(struct net_device *netdev,
> 			    struct idpf_q_vector *q_vector,
> 			    enum netdev_queue_type q_type,
> 			    struct napi_struct *napi)
> {
> 	u32 q_cnt = q_type == NETDEV_QUEUE_TYPE_RX ? q_vector->num_rxq :
> 						     q_vector->num_txq;
> 	struct idpf_rx_queue **qs = q_type == NETDEV_QUEUE_TYPE_RX ?
> 					      q_vector->rx : q_vector->tx;
> 
> 	for (u32 i = 0; i < q_cnt; i++)
> 		netif_queue_set_napi(netdev, qs[i]->idx, q_type, napi);
> }
> 
> idpf_q_set_napi(vport->netdev, q_vector, NETDEV_QUEUE_TYPE_RX, NULL);
> idpf_q_set_napi(vport->netdev, q_vector, NETDEV_QUEUE_TYPE_TX, NULL);
> ...
> idpf_q_set_napi(vport->netdev, q_vector, NETDEV_QUEUE_TYPE_RX, &q_vector->napi);
> idpf_q_set_napi(vport->netdev, q_vector, NETDEV_QUEUE_TYPE_TX, &q_vector->napi);
> 
> 
> up to you if you take it, less lines in the end but i don't have strong
> opinion if this should be considered as an improvement or makes code
> harder to follow.

No no, it's actually a good idea. Previously, it looked different, but
then this stuff with the CPU affinity embedded into the NAPI config got
merged and I had to rewrite this in the last minute.

> 
>>  		kfree(free_irq(irq_num, q_vector));
>>  	}
>> +
>> +	if (unlock)
>> +		rtnl_unlock();
>>  }

Thanks,
Olek