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

[Ori Kam <orika@mellanox.com>]

Hi Ferruh,

> -----Original Message-----
> From: Ferruh Yigit <ferruh.yigit@intel.com>
> Sent: Wednesday, January 15, 2020 4:02 PM
> To: Ori Kam <orika@mellanox.com>; Matan Azrad <matan@mellanox.com>;
> Shahaf Shuler <shahafs@mellanox.com>; Slava Ovsiienko
> <viacheslavo@mellanox.com>
> Cc: dev@dpdk.org
> Subject: Re: [PATCH 2/2] net/mlx5: add fine grain dynamic flag support
> 
> 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.
> 
Will add validation to make sure names != NULL,

> > +	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.
> 

Will add.

> > +
> > +#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?

The data path implementation will be done in different patch.
The flags is set for example using the testpmd new API or by the application.
The reason that I added this patch is to show usage for the testpmd patch, I can remove this patch and 
re send it when sending the datapath patch.
What do you think?