Re: [PATCH net-next] eth: mlx5: link NAPI instances to queues and IRQs

[Tariq Toukan <tariqt@nvidia.com>]

On 06/02/2024 19:12, Joe Damato wrote:
> On Tue, Feb 06, 2024 at 10:11:28AM +0200, Tariq Toukan wrote:
>>
>>
>> On 06/02/2024 3:03, Joe Damato wrote:
>>> Make mlx5 compatible with the newly added netlink queue GET APIs.
>>>
>>> Signed-off-by: Joe Damato <jdamato@fastly.com>
>>
>> + Gal
>>
>> Hi Joe,
>> Thanks for your patch.
>>
>> We have already prepared a similar patch, and it's part of our internal
>> submission queue, and planned to be submitted soon.
>>
>> Please see my comments below, let us know if you're welling to respin a V2
>> or wait for our patch.
> 
> Do you have a rough estimate on when it'll be submitted?
> 
> If it's several months out I'll try again, but if it's expected to be
> submit in the next few weeks I'll wait for your official change.

It'll be in the next few weeks.

> 
> BTW, are the per queue coalesce changes in that same queue? It was
> mentioned previously [1] that this feature is coming after we submit a
> simple attempt as an RFC. If that feature isn't planned or won't be submit
> anytime soon, can you let us know and we can try to attempt an RFC v3 for
> it?
> 

The per queue coalesce series is going through internal code review, and 
is expected to also be ready in a matter of a few weeks.

> [1]: https://lore.kernel.org/lkml/874jj34e67.fsf@nvidia.com/
> 
>>> ---
>>>   drivers/net/ethernet/mellanox/mlx5/core/en.h      | 1 +
>>>   drivers/net/ethernet/mellanox/mlx5/core/en_main.c | 8 ++++++++
>>>   2 files changed, 9 insertions(+)
>>>
>>> diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en.h b/drivers/net/ethernet/mellanox/mlx5/core/en.h
>>> index 55c6ace0acd5..3f86ee1831a8 100644
>>> --- a/drivers/net/ethernet/mellanox/mlx5/core/en.h
>>> +++ b/drivers/net/ethernet/mellanox/mlx5/core/en.h
>>> @@ -768,6 +768,7 @@ struct mlx5e_channel {
>>>   	u16                        qos_sqs_size;
>>>   	u8                         num_tc;
>>>   	u8                         lag_port;
>>> +	unsigned int		   irq;
>>>   	/* XDP_REDIRECT */
>>>   	struct mlx5e_xdpsq         xdpsq;
>>> diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
>>> index c8e8f512803e..e1bfff1fb328 100644
>>> --- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
>>> +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
>>> @@ -2473,6 +2473,9 @@ static void mlx5e_close_queues(struct mlx5e_channel *c)
>>>   	mlx5e_close_tx_cqs(c);
>>>   	mlx5e_close_cq(&c->icosq.cq);
>>>   	mlx5e_close_cq(&c->async_icosq.cq);
>>> +
>>> +	netif_queue_set_napi(c->netdev, c->ix, NETDEV_QUEUE_TYPE_TX, NULL);
>>> +	netif_queue_set_napi(c->netdev, c->ix, NETDEV_QUEUE_TYPE_RX, NULL);
>>>   }
>>>   static u8 mlx5e_enumerate_lag_port(struct mlx5_core_dev *mdev, int ix)
>>> @@ -2558,6 +2561,7 @@ static int mlx5e_open_channel(struct mlx5e_priv *priv, int ix,
>>>   	c->stats    = &priv->channel_stats[ix]->ch;
>>>   	c->aff_mask = irq_get_effective_affinity_mask(irq);
>>>   	c->lag_port = mlx5e_enumerate_lag_port(priv->mdev, ix);
>>> +	c->irq		= irq;
>>>   	netif_napi_add(netdev, &c->napi, mlx5e_napi_poll);
>>> @@ -2602,6 +2606,10 @@ static void mlx5e_activate_channel(struct mlx5e_channel *c)
>>>   		mlx5e_activate_xsk(c);
>>>   	else
>>>   		mlx5e_activate_rq(&c->rq);
>>> +
>>> +	netif_napi_set_irq(&c->napi, c->irq);
>>
>> Can be safely moved to mlx5e_open_channel without interfering with other
>> existing mapping. This would save the new irq field in mlx5e_channel.
> 
> Sure, yea, I have that change queued already from last night.
> 

I see now.. I replied before noticing it.

>>> +	netif_queue_set_napi(c->netdev, c->ix, NETDEV_QUEUE_TYPE_TX, &c->napi);
>>
>> In some configurations we have multiple txqs per channel, so the txq indices
>> are not 1-to-1 with their channel index.
>>
>> This should be called per each txq, with the proper txq index.
>>
>> It should be done also for feture-dedicated SQs (like QOS/HTB).
> 
> OK. I think the above makes sense and I'll look into it if I have some time
> this week.
>   
>>> +	netif_queue_set_napi(c->netdev, c->ix, NETDEV_QUEUE_TYPE_RX, &c->napi);
>>
>> For consistency, I'd move this one as well, to match the TX handling.
> 
> Sure.
> 
>>>   }
>>>   static void mlx5e_deactivate_channel(struct mlx5e_channel *c)