Re: [PATCH] net/mlx5: implement drop action in hardware classifier

["Nélio Laranjeiro" <nelio.laranjeiro@6wind.com>]

Shachar,

Please see the few comments above,

On Thu, May 25, 2017 at 01:05:58PM +0000, Shachar Beiser wrote:
> The current drop action is implemented as a queue tail drop,
> requiring to instantiate multiple WQs to maintain high drop rate.
> This commit, implements the drop action in hardware classifier.
> This enables to reduce the amount of contexts needed for the drop,
> without affecting the drop rate.
> 
> Signed-off-by: Shachar Beiser <shacharbe@mellanox.com>
> ---
>  drivers/net/mlx5/Makefile    |  5 ++++
>  drivers/net/mlx5/mlx5_flow.c | 56 ++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 61 insertions(+)
> 
> diff --git a/drivers/net/mlx5/Makefile b/drivers/net/mlx5/Makefile
> index c079959..daf8013 100644
> --- a/drivers/net/mlx5/Makefile
> +++ b/drivers/net/mlx5/Makefile
> @@ -101,6 +101,11 @@ mlx5_autoconf.h.new: FORCE
>  mlx5_autoconf.h.new: $(RTE_SDK)/buildtools/auto-config-h.sh
>  	$Q $(RM) -f -- '$@'
>  	$Q sh -- '$<' '$@' \
> +		HAVE_VERBS_IBV_EXP_FLOW_SPEC_ACTION_DROP \
> +		infiniband/verbs_exp.h \
> +		enum IBV_EXP_FLOW_SPEC_ACTION_DROP \
> +		$(AUTOCONF_OUTPUT)
> +	$Q sh -- '$<' '$@' \
>  		HAVE_VERBS_IBV_EXP_CQ_COMPRESSED_CQE \
>  		infiniband/verbs_exp.h \
>  		enum IBV_EXP_CQ_COMPRESSED_CQE \
> diff --git a/drivers/net/mlx5/mlx5_flow.c b/drivers/net/mlx5/mlx5_flow.c
> index adcbe3f..d132d85 100644
> --- a/drivers/net/mlx5/mlx5_flow.c
> +++ b/drivers/net/mlx5/mlx5_flow.c
> @@ -994,6 +994,12 @@ struct mlx5_flow_action {
>  {
>  	struct rte_flow *rte_flow;
>  
> +#ifdef HAVE_VERBS_IBV_EXP_FLOW_SPEC_ACTION_DROP
> +
> +	struct ibv_exp_flow_spec_action_drop *drop;
> +
> +	unsigned int size = sizeof(struct ibv_exp_flow_spec_action_drop);
> +#endif

Remove those extra lines, it does not respect the file coding style.

>  	assert(priv->pd);
>  	assert(priv->ctx);
>  	rte_flow = rte_calloc(__func__, 1, sizeof(*rte_flow), 0);
> @@ -1007,6 +1013,15 @@ struct mlx5_flow_action {
>  	rte_flow->qp = priv->flow_drop_queue->qp;
>  	if (!priv->started)
>  		return rte_flow;
> +#ifdef HAVE_VERBS_IBV_EXP_FLOW_SPEC_ACTION_DROP
> +	drop = (void *)((uintptr_t)flow->ibv_attr + flow->offset);
> +	*drop = (struct ibv_exp_flow_spec_action_drop){
> +			.type = IBV_EXP_FLOW_SPEC_ACTION_DROP,
> +			.size = size,
> +	};
> +	++flow->ibv_attr->num_of_specs;
> +	flow->offset += sizeof(struct ibv_exp_flow_spec_action_drop);
> +#endif
>  	rte_flow->ibv_flow = ibv_exp_create_flow(rte_flow->qp,
>  						 rte_flow->ibv_attr);
>  	if (!rte_flow->ibv_flow) {
> @@ -1370,8 +1385,10 @@ struct rte_flow *
>  priv_flow_create_drop_queue(struct priv *priv)
>  {
>  	struct rte_flow_drop *fdq = NULL;
> +#ifndef HAVE_VERBS_IBV_EXP_FLOW_SPEC_ACTION_DROP
>  	unsigned int i;
>  
> +#endif

The empty line should be after the #endif not before.

>  	assert(priv->pd);
>  	assert(priv->ctx);
>  	fdq = rte_calloc(__func__, 1, sizeof(*fdq), 0);
> @@ -1387,6 +1404,7 @@ struct rte_flow *
>  		WARN("cannot allocate CQ for drop queue");
>  		goto error;
>  	}
> +#ifndef HAVE_VERBS_IBV_EXP_FLOW_SPEC_ACTION_DROP
>  	for (i = 0; i != MLX5_DROP_WQ_N; ++i) {
>  		fdq->wqs[i] = ibv_exp_create_wq(priv->ctx,
>  				&(struct ibv_exp_wq_init_attr){
> @@ -1412,6 +1430,31 @@ struct rte_flow *
>  		WARN("cannot allocate indirection table for drop queue");
>  		goto error;
>  	}
> +#else
> +	fdq->wqs[0] = ibv_exp_create_wq(priv->ctx,
> +			&(struct ibv_exp_wq_init_attr){
> +			.wq_type = IBV_EXP_WQT_RQ,
> +			.max_recv_wr = 1,
> +			.max_recv_sge = 1,
> +			.pd = priv->pd,
> +			.cq = fdq->cq,
> +			});
> +	if (!fdq->wqs[0]) {
> +		WARN("cannot allocate WQ for drop queue");
> +		goto error;
> +	}

>From here...

> +	fdq->ind_table = ibv_exp_create_rwq_ind_table(priv->ctx,
> +			&(struct ibv_exp_rwq_ind_table_init_attr){
> +			.pd = priv->pd,
> +			.log_ind_tbl_size = 0,
> +			.ind_tbl = fdq->wqs,
> +			.comp_mask = 0,
> +			});
> +	if (!fdq->ind_table) {
> +		WARN("cannot allocate indirection table for drop queue");
> +		goto error;
> +	}
> +#endif
>[...]

To this point, the code is copy/paste from the block above, it should
not be present.  Please keep the diff as small as possible.

Thanks,

-- 
Nélio Laranjeiro
6WIND