Re: [PATCH net-next 10/12] net/mlx4_en: Add NAPI support for transmit side

[Amir Vadai <amirv@mellanox.com>]

On 08/12/2013 21:22, Eric Dumazet wrote:
> On Sun, 2013-12-08 at 14:35 +0200, Amir Vadai wrote:
>> From: Eugenia Emantayev <eugenia@mellanox.com>
>>
>> Add NAPI for TX side,
>> implement its support and provide NAPI callback.
>>
>>
>> Signed-off-by: Yevgeny Petrilin <yevgenyp@mellanox.com>
>> Signed-off-by: Eugenia Emantayev <eugenia@mellanox.com>
>> Signed-off-by: Amir Vadai <amirv@mellanox.com>
>> ---
>>  drivers/net/ethernet/mellanox/mlx4/en_cq.c   | 12 ++++++---
>>  drivers/net/ethernet/mellanox/mlx4/en_tx.c   | 39 +++++++++++++++++++++++-----
>>  drivers/net/ethernet/mellanox/mlx4/mlx4_en.h |  3 +++
>>  3 files changed, 43 insertions(+), 11 deletions(-)
>>
>> diff --git a/drivers/net/ethernet/mellanox/mlx4/en_cq.c b/drivers/net/ethernet/mellanox/mlx4/en_cq.c
>> index 3a098cc..2c60f0c 100644
>> --- a/drivers/net/ethernet/mellanox/mlx4/en_cq.c
>> +++ b/drivers/net/ethernet/mellanox/mlx4/en_cq.c
>> @@ -161,12 +161,16 @@ int mlx4_en_activate_cq(struct mlx4_en_priv *priv, struct mlx4_en_cq *cq,
>>  	cq->mcq.comp  = cq->is_tx ? mlx4_en_tx_irq : mlx4_en_rx_irq;
>>  	cq->mcq.event = mlx4_en_cq_event;
>>  
>> -	if (!cq->is_tx) {
>> +	if (cq->is_tx) {
>> +		netif_napi_add(cq->dev, &cq->napi, mlx4_en_poll_tx_cq,
>> +			       MLX4_EN_TX_BUDGET);
>> +	} else {
> 
> TX completion is not supposed to have a 'budget'.
> 
> You should consume all completed descriptors.
> 
> BQL should already drive the dynamic of the TX queue.
Actually MLX4_EN_TX_BUDGET is 64 already.
Will use NAPI_POLL_WEIGHT instead in V1.

Amir