Re: [dpdk-dev] [PATCH 2/2] net/mlx5: add fine grain dynamic flag support

[Ferruh Yigit <ferruh.yigit@intel.com>]

On 1/13/2020 9:29 AM, Ori Kam wrote:
> The inline feature is designed to save PCI bandwidth by copying some
> of the data to the wqe. This feature if enabled works for all packets.
> 
> In some cases when using external memory, the PCI bandwidth is not
> relevant since the memory can be accessed by other means.
> 
> This commit introduce the ability to control the inline with mbuf
> granularity.
> 
> In order to use this feature the application should register the field
> name, and restart the port.
> 
> Signed-off-by: Ori Kam <orika@mellanox.com>
> Acked-by: Viacheslav Ovsiienko <viacheslavo@mellanox.com>
> ---
>  drivers/net/mlx5/mlx5.c                   | 15 +++++++++++++++
>  drivers/net/mlx5/mlx5_rxtx.c              |  2 ++
>  drivers/net/mlx5/mlx5_rxtx.h              |  3 +++
>  drivers/net/mlx5/mlx5_trigger.c           |  8 ++++++++
>  drivers/net/mlx5/rte_pmd_mlx5.h           | 32 +++++++++++++++++++++++++++++++
>  drivers/net/mlx5/rte_pmd_mlx5_version.map |  7 +++++++
>  6 files changed, 67 insertions(+)
>  create mode 100644 drivers/net/mlx5/rte_pmd_mlx5.h
> 
> diff --git a/drivers/net/mlx5/mlx5.c b/drivers/net/mlx5/mlx5.c
> index 50960c9..27dbe27 100644
> --- a/drivers/net/mlx5/mlx5.c
> +++ b/drivers/net/mlx5/mlx5.c
> @@ -46,6 +46,7 @@
>  #include "mlx5_glue.h"
>  #include "mlx5_mr.h"
>  #include "mlx5_flow.h"
> +#include "rte_pmd_mlx5.h"
>  
>  /* Device parameter to enable RX completion queue compression. */
>  #define MLX5_RXQ_CQE_COMP_EN "rxq_cqe_comp_en"
> @@ -1988,6 +1989,20 @@ struct mlx5_flow_id_pool *
>  	return ret;
>  }
>  
> +int
> +rte_pmd_mlx5_get_dyn_flag_names(char *names[], uint16_t n)
> +{

Now this is a public API, it should validate the user input.

> +	static const char *const dynf_names[] = {
> +		RTE_PMD_MLX5_FINE_GRANULARITY_INLINE,
> +	};
> +	int num = RTE_MIN(n, RTE_DIM(dynf_names));
> +	int i;
> +
> +	for (i = 0; i < num; i++)
> +		strcpy(names[i], dynf_names[i]);
> +	return num;
> +}
> +
>  /**
>   * Check sibling device configurations.
>   *
> diff --git a/drivers/net/mlx5/mlx5_rxtx.c b/drivers/net/mlx5/mlx5_rxtx.c
> index 67cafd1..aa6aa22 100644
> --- a/drivers/net/mlx5/mlx5_rxtx.c
> +++ b/drivers/net/mlx5/mlx5_rxtx.c
> @@ -126,6 +126,8 @@ enum mlx5_txcmp_code {
>  uint8_t mlx5_cksum_table[1 << 10] __rte_cache_aligned;
>  uint8_t mlx5_swp_types_table[1 << 10] __rte_cache_aligned;
>  
> +uint64_t rte_net_mlx5_dynf_inline_mask;
> +
>  /**
>   * Build a table to translate Rx completion flags to packet type.
>   *
> diff --git a/drivers/net/mlx5/mlx5_rxtx.h b/drivers/net/mlx5/mlx5_rxtx.h
> index e362b4a..7c38c57 100644
> --- a/drivers/net/mlx5/mlx5_rxtx.h
> +++ b/drivers/net/mlx5/mlx5_rxtx.h
> @@ -42,6 +42,9 @@
>  /* Support tunnel matching. */
>  #define MLX5_FLOW_TUNNEL 9
>  
> +/* Mbuf dynamic flag offset for inline. */
> +extern uint64_t rte_net_mlx5_dynf_inline_mask;
> +
>  struct mlx5_rxq_stats {
>  #ifdef MLX5_PMD_SOFT_COUNTERS
>  	uint64_t ipackets; /**< Total of successfully received packets. */
> diff --git a/drivers/net/mlx5/mlx5_trigger.c b/drivers/net/mlx5/mlx5_trigger.c
> index ab6937a..ab253b2 100644
> --- a/drivers/net/mlx5/mlx5_trigger.c
> +++ b/drivers/net/mlx5/mlx5_trigger.c
> @@ -13,6 +13,7 @@
>  #include "mlx5.h"
>  #include "mlx5_rxtx.h"
>  #include "mlx5_utils.h"
> +#include "rte_pmd_mlx5.h"
>  
>  /**
>   * Stop traffic on Tx queues.
> @@ -270,8 +271,15 @@
>  {
>  	struct mlx5_priv *priv = dev->data->dev_private;
>  	int ret;
> +	int fine_inline;
>  
>  	DRV_LOG(DEBUG, "port %u starting device", dev->data->port_id);
> +	fine_inline = rte_mbuf_dynflag_lookup
> +		(RTE_PMD_MLX5_FINE_GRANULARITY_INLINE, NULL);
> +	if (fine_inline > 0)
> +		rte_net_mlx5_dynf_inline_mask = 1UL << fine_inline;
> +	else
> +		rte_net_mlx5_dynf_inline_mask = 0;
>  	ret = mlx5_dev_configure_rss_reta(dev);
>  	if (ret) {
>  		DRV_LOG(ERR, "port %u reta config failed: %s",
> diff --git a/drivers/net/mlx5/rte_pmd_mlx5.h b/drivers/net/mlx5/rte_pmd_mlx5.h
> new file mode 100644
> index 0000000..12e18ca
> --- /dev/null
> +++ b/drivers/net/mlx5/rte_pmd_mlx5.h
> @@ -0,0 +1,32 @@
> +/* SPDX-License-Identifier: BSD-3-Clause
> + * Copyright 2020 Mellanox Technologies, Ltd
> + */
> +
> +#ifndef RTE_PMD_PRIVATE_MLX5_H_
> +#define RTE_PMD_PRIVATE_MLX5_H_
> +
> +/**
> + * @file
> + * MLX5 public header.
> + *
> + * This interface provides the ability to support private PMD
> + * dynamic flags.
> + */
> +
> +#define RTE_PMD_MLX5_FINE_GRANULARITY_INLINE "mlx5_fine_granularity_inline"
> +
> +/**
> + * Returns the dynamic flags name, that are supported.
> + *
> + * @param[out] names
> + *   Array that is used to return the supported dynamic flags names.
> + * @param[in] n
> + *   The number of elements in the names array.
> + *
> + * @return
> + *   The number of dynamic flags that were copied.
> + */
> +__rte_experimental
> +int rte_pmd_mlx5_get_dyn_flag_names(char *names[], uint16_t n);

Can you please add this header to the API documentation index,
doc/api/doxy-api-index.md, so it will be part of API document.

> +
> +#endif
> diff --git a/drivers/net/mlx5/rte_pmd_mlx5_version.map b/drivers/net/mlx5/rte_pmd_mlx5_version.map
> index f9f17e4..c8b1031 100644
> --- a/drivers/net/mlx5/rte_pmd_mlx5_version.map
> +++ b/drivers/net/mlx5/rte_pmd_mlx5_version.map
> @@ -1,3 +1,10 @@
>  DPDK_20.0 {
>  	local: *;
>  };
> +
> +EXPERIMENTAL {
> +        global:
> +
> +        # added in 20.02
> +	rte_pmd_mlx5_get_dyn_flag_names;
> +};
> 

Isn't the datapath implementation missing? Where this new mbuf dynamic flag set
or checked?