Re: [dpdk-dev] [PATCH v2 3/3] ixgbe: Unify the rx_pkt_bulk callback initialization

["Ananyev, Konstantin" <konstantin.ananyev@intel.com>]

> -----Original Message-----
> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Vlad Zolotarov
> Sent: Monday, March 09, 2015 4:29 PM
> To: dev@dpdk.org
> Subject: [dpdk-dev] [PATCH v2 3/3] ixgbe: Unify the rx_pkt_bulk callback initialization
> 
>    - Set the callback in a single function that is called from
>      ixgbe_dev_rx_init() for a primary process and from eth_ixgbe_dev_init()
>      for a secondary processes. This is instead of multiple, hard to track places.
>    - Added ixgbe_hw.rx_bulk_alloc_allowed - see ixgbe_hw.rx_vec_allowed description below.
>    - Added ixgbe_hw.rx_vec_allowed: like with Bulk Allocation, Vector Rx is
>      enabled or disabled on a per-port level. All queues have to meet the appropriate
>      preconditions and if any of them doesn't - the feature has to be disabled.
>      Therefore ixgbe_hw.rx_vec_allowed will be updated during each queues configuration
>      (rte_eth_rx_queue_setup()) and then used in rte_eth_dev_start() to configure the
>      appropriate callbacks. The same happens with ixgbe_hw.rx_vec_allowed in a Bulk Allocation
>      context.
>    - Bugs fixed:
>       - Vector scattered packets callback was called regardless the appropriate
>         preconditions:
>          - Vector Rx specific preconditions.
>          - Bulk Allocation preconditions.
>       - Vector Rx was enabled/disabled according to the last queue setting and not
>         based on all queues setting (which may be different for each queue).
> 
> Signed-off-by: Vlad Zolotarov <vladz@cloudius-systems.com>
> ---
> New in v2:
>    - Fixed an broken compilation.
> ---
>  lib/librte_pmd_ixgbe/ixgbe/ixgbe_type.h |   2 +
>  lib/librte_pmd_ixgbe/ixgbe_ethdev.c     |  13 ++-
>  lib/librte_pmd_ixgbe/ixgbe_rxtx.c       | 183 +++++++++++++++++++++-----------
>  lib/librte_pmd_ixgbe/ixgbe_rxtx.h       |  22 +++-
>  4 files changed, 152 insertions(+), 68 deletions(-)
> 
> diff --git a/lib/librte_pmd_ixgbe/ixgbe/ixgbe_type.h b/lib/librte_pmd_ixgbe/ixgbe/ixgbe_type.h
> index c67d462..9a66370 100644
> --- a/lib/librte_pmd_ixgbe/ixgbe/ixgbe_type.h
> +++ b/lib/librte_pmd_ixgbe/ixgbe/ixgbe_type.h
> @@ -3657,6 +3657,8 @@ struct ixgbe_hw {
>  	bool force_full_reset;
>  	bool allow_unsupported_sfp;
>  	bool wol_enabled;
> +	bool rx_bulk_alloc_allowed;
> +	bool rx_vec_allowed;
>  };
> 
>  #define ixgbe_call_func(hw, func, params, error) \
> diff --git a/lib/librte_pmd_ixgbe/ixgbe_ethdev.c b/lib/librte_pmd_ixgbe/ixgbe_ethdev.c
> index 9bdc046..9d3de1a 100644
> --- a/lib/librte_pmd_ixgbe/ixgbe_ethdev.c
> +++ b/lib/librte_pmd_ixgbe/ixgbe_ethdev.c
> @@ -760,8 +760,8 @@ eth_ixgbe_dev_init(__attribute__((unused)) struct eth_driver *eth_drv,
>  			                   "Using default TX function.");
>  		}
> 
> -		if (eth_dev->data->scattered_rx)
> -			eth_dev->rx_pkt_burst = ixgbe_recv_scattered_pkts;
> +		set_rx_function(eth_dev);
> +
>  		return 0;
>  	}
>  	pci_dev = eth_dev->pci_dev;
> @@ -772,6 +772,13 @@ eth_ixgbe_dev_init(__attribute__((unused)) struct eth_driver *eth_drv,
>  	hw->hw_addr = (void *)pci_dev->mem_resource[0].addr;
>  	hw->allow_unsupported_sfp = 1;
> 
> +	/*
> +	 * Initialize to TRUE. If any of Rx queues doesn't meet the bulk
> +	 * allocation or vector Rx preconditions we will reset it.
> +	 */
> +	hw->rx_bulk_alloc_allowed = true;
> +	hw->rx_vec_allowed = true;
> +
>  	/* Initialize the shared code (base driver) */
>  #ifdef RTE_NIC_BYPASS
>  	diag = ixgbe_bypass_init_shared_code(hw);
> @@ -1641,6 +1648,8 @@ ixgbe_dev_stop(struct rte_eth_dev *dev)
> 
>  	/* Clear stored conf */
>  	dev->data->scattered_rx = 0;
> +	hw->rx_bulk_alloc_allowed = false;
> +	hw->rx_vec_allowed = false;

If dev_stop() sets it to 'false', who will reset it back to 'true' then?

> 
>  	/* Clear recorded link status */
>  	memset(&link, 0, sizeof(link));
> diff --git a/lib/librte_pmd_ixgbe/ixgbe_rxtx.c b/lib/librte_pmd_ixgbe/ixgbe_rxtx.c
> index ce9658e..a00f5c9 100644
> --- a/lib/librte_pmd_ixgbe/ixgbe_rxtx.c
> +++ b/lib/librte_pmd_ixgbe/ixgbe_rxtx.c
> @@ -2074,12 +2074,12 @@ check_rx_burst_bulk_alloc_preconditions(__rte_unused struct igb_rx_queue *rxq)
> 
>  /* Reset dynamic igb_rx_queue fields back to defaults */
>  static void
> -ixgbe_reset_rx_queue(struct igb_rx_queue *rxq)
> +ixgbe_reset_rx_queue(struct ixgbe_hw *hw, struct igb_rx_queue *rxq)
>  {
>  	static const union ixgbe_adv_rx_desc zeroed_desc = { .read = {
>  			.pkt_addr = 0}};
>  	unsigned i;
> -	uint16_t len;
> +	uint16_t len = rxq->nb_rx_desc;
> 
>  	/*
>  	 * By default, the Rx queue setup function allocates enough memory for
> @@ -2091,14 +2091,9 @@ ixgbe_reset_rx_queue(struct igb_rx_queue *rxq)
>  	 * constraints here to see if we need to zero out memory after the end
>  	 * of the H/W descriptor ring.
>  	 */
> -#ifdef RTE_LIBRTE_IXGBE_RX_ALLOW_BULK_ALLOC
> -	if (check_rx_burst_bulk_alloc_preconditions(rxq) == 0)
> +	if (hw->rx_bulk_alloc_allowed)
>  		/* zero out extra memory */
> -		len = (uint16_t)(rxq->nb_rx_desc + RTE_PMD_IXGBE_RX_MAX_BURST);
> -	else
> -#endif
> -		/* do not zero out extra memory */
> -		len = rxq->nb_rx_desc;
> +		len += RTE_PMD_IXGBE_RX_MAX_BURST;
> 
>  	/*
>  	 * Zero out HW ring memory. Zero out extra memory at the end of
> @@ -2140,7 +2135,6 @@ ixgbe_dev_rx_queue_setup(struct rte_eth_dev *dev,
>  	const struct rte_memzone *rz;
>  	struct igb_rx_queue *rxq;
>  	struct ixgbe_hw     *hw;
> -	int use_def_burst_func = 1;
>  	uint16_t len;
> 
>  	PMD_INIT_FUNC_TRACE();
> @@ -2221,15 +2215,27 @@ ixgbe_dev_rx_queue_setup(struct rte_eth_dev *dev,
>  	rxq->rx_ring = (union ixgbe_adv_rx_desc *) rz->addr;
> 
>  	/*
> +	 * Certain constraints must be met in order to use the bulk buffer
> +	 * allocation Rx burst function. If any of Rx queues doesn't meet them
> +	 * the feature should be disabled for the whole port.
> +	 */
> +	if (check_rx_burst_bulk_alloc_preconditions(rxq)) {
> +		PMD_INIT_LOG(DEBUG, "queue[%d] doesn't meet Rx Bulk Alloc "
> +				    "preconditions - canceling the feature for "
> +				    "the whole port[%d]",
> +			     rxq->queue_id, rxq->port_id);
> +		hw->rx_bulk_alloc_allowed = false;
> +	}
> +
> +	/*
>  	 * Allocate software ring. Allow for space at the end of the
>  	 * S/W ring to make sure look-ahead logic in bulk alloc Rx burst
>  	 * function does not access an invalid memory region.
>  	 */
> -#ifdef RTE_LIBRTE_IXGBE_RX_ALLOW_BULK_ALLOC
> -	len = (uint16_t)(nb_desc + RTE_PMD_IXGBE_RX_MAX_BURST);
> -#else
>  	len = nb_desc;
> -#endif
> +	if (hw->rx_bulk_alloc_allowed)
> +		len += RTE_PMD_IXGBE_RX_MAX_BURST;
> +

Looking at it: it is probably easier and cleaner to remove all these ifdefs if/else
And always setup len = nb_desc + RTE_PMD_IXGBE_RX_MAX_BURST;


>  	rxq->sw_ring = rte_zmalloc_socket("rxq->sw_ring",
>  					  sizeof(struct igb_rx_entry) * len,
>  					  RTE_CACHE_LINE_SIZE, socket_id);
> @@ -2240,42 +2246,18 @@ ixgbe_dev_rx_queue_setup(struct rte_eth_dev *dev,
>  	PMD_INIT_LOG(DEBUG, "sw_ring=%p hw_ring=%p dma_addr=0x%"PRIx64,
>  		     rxq->sw_ring, rxq->rx_ring, rxq->rx_ring_phys_addr);
> 
> -	/*
> -	 * Certain constraints must be met in order to use the bulk buffer
> -	 * allocation Rx burst function.
> -	 */
> -	use_def_burst_func = check_rx_burst_bulk_alloc_preconditions(rxq);
> +	if (!rte_is_power_of_2(nb_desc)) {
> +		PMD_INIT_LOG(DEBUG, "queue[%d] doesn't meet Vector Rx "
> +				    "preconditions - canceling the feature for "
> +				    "the whole port[%d]",
> +			     rxq->queue_id, rxq->port_id);
> +		hw->rx_vec_allowed = false;
> +	} else
> +		ixgbe_rxq_vec_setup(rxq);
> 
> -#ifdef RTE_IXGBE_INC_VECTOR
> -	ixgbe_rxq_vec_setup(rxq);
> -#endif
> -	/* Check if pre-conditions are satisfied, and no Scattered Rx */
> -	if (!use_def_burst_func && !dev->data->scattered_rx) {
> -#ifdef RTE_LIBRTE_IXGBE_RX_ALLOW_BULK_ALLOC
> -		PMD_INIT_LOG(DEBUG, "Rx Burst Bulk Alloc Preconditions are "
> -			     "satisfied. Rx Burst Bulk Alloc function will be "
> -			     "used on port=%d, queue=%d.",
> -			     rxq->port_id, rxq->queue_id);
> -		dev->rx_pkt_burst = ixgbe_recv_pkts_bulk_alloc;
> -#ifdef RTE_IXGBE_INC_VECTOR
> -		if (!ixgbe_rx_vec_condition_check(dev) &&
> -		    (rte_is_power_of_2(nb_desc))) {
> -			PMD_INIT_LOG(INFO, "Vector rx enabled, please make "
> -				     "sure RX burst size no less than 32.");
> -			dev->rx_pkt_burst = ixgbe_recv_pkts_vec;
> -		}
> -#endif
> -#endif
> -	} else {
> -		PMD_INIT_LOG(DEBUG, "Rx Burst Bulk Alloc Preconditions "
> -			     "are not satisfied, Scattered Rx is requested, "
> -			     "or RTE_LIBRTE_IXGBE_RX_ALLOW_BULK_ALLOC is not "
> -			     "enabled (port=%d, queue=%d).",
> -			     rxq->port_id, rxq->queue_id);
> -	}
>  	dev->data->rx_queues[queue_idx] = rxq;
> 
> -	ixgbe_reset_rx_queue(rxq);
> +	ixgbe_reset_rx_queue(hw, rxq);
> 
>  	return 0;
>  }
> @@ -2329,6 +2311,7 @@ void
>  ixgbe_dev_clear_queues(struct rte_eth_dev *dev)
>  {
>  	unsigned i;
> +	struct ixgbe_hw *hw = IXGBE_DEV_PRIVATE_TO_HW(dev->data->dev_private);
> 
>  	PMD_INIT_FUNC_TRACE();
> 
> @@ -2344,7 +2327,7 @@ ixgbe_dev_clear_queues(struct rte_eth_dev *dev)
>  		struct igb_rx_queue *rxq = dev->data->rx_queues[i];
>  		if (rxq != NULL) {
>  			ixgbe_rx_queue_release_mbufs(rxq);
> -			ixgbe_reset_rx_queue(rxq);
> +			ixgbe_reset_rx_queue(hw, rxq);
>  		}
>  	}
>  }
> @@ -3506,6 +3489,58 @@ ixgbe_dev_mq_tx_configure(struct rte_eth_dev *dev)
>  	return 0;
>  }
> 
> +void set_rx_function(struct rte_eth_dev *dev)
> +{
> +	struct ixgbe_hw *hw = IXGBE_DEV_PRIVATE_TO_HW(dev->data->dev_private);
> +
> +	if (ixgbe_rx_vec_condition_check(dev)) {
> +		PMD_INIT_LOG(DEBUG, "Port[%d] doesn't meet Vector Rx "
> +				    "preconditions or RTE_IXGBE_INC_VECTOR is "
> +				    "not enabled",
> +			     dev->data->port_id);
> +		hw->rx_vec_allowed = false;
> +	}
> +
> +	/* Check if bulk alloc is allowed and no Scattered Rx */
> +	if (hw->rx_bulk_alloc_allowed && !dev->data->scattered_rx) {
> +		PMD_INIT_LOG(DEBUG, "Rx Burst Bulk Alloc Preconditions are "
> +				    "satisfied. Rx Burst Bulk Alloc function "
> +				    "will be used on port=%d.",
> +			     dev->data->port_id);
> +		dev->rx_pkt_burst = ixgbe_recv_pkts_bulk_alloc;
> +
> +		if (hw->rx_vec_allowed) {
> +			PMD_INIT_LOG(INFO, "Vector rx enabled, please make "
> +					   "sure RX burst size no less "
> +					   "than 32.");
> +			dev->rx_pkt_burst = ixgbe_recv_pkts_vec;
> +		}
> +	} else {
> +		dev->rx_pkt_burst = ixgbe_recv_pkts;
> +
> +		PMD_INIT_LOG(DEBUG, "Rx Burst Bulk Alloc Preconditions are not "
> +				    "satisfied, or Scattered Rx is requested, "
> +				    "or RTE_LIBRTE_IXGBE_RX_ALLOW_BULK_ALLOC "
> +				    "is not enabled (port=%d).",
> +			     dev->data->port_id);
> +	}
> +
> +	if (dev->data->scattered_rx) {
> +		if (hw->rx_vec_allowed && hw->rx_bulk_alloc_allowed) {
> +			PMD_INIT_LOG(DEBUG, "Using Vector Scattered Rx "
> +					    "callback (port=%d).",
> +				     dev->data->port_id);
> +			dev->rx_pkt_burst = ixgbe_recv_scattered_pkts_vec;
> +		} else {
> +			PMD_INIT_LOG(DEBUG, "Using Regualr (non-vector) "
> +					    "Scattered Rx callback "
> +					    "(port=%d).",
> +				     dev->data->port_id);
> +			dev->rx_pkt_burst = ixgbe_recv_scattered_pkts;
> +		}
> +	}
> +}

if scattered_rx != 0 it will setup rx_pkt_burst twice.
Nothing wrong, but looks a bit clumsy.
Might be a bit clearer to reorder it a bit:

If (scattered_rx) {
   ...
} else if (rx_bulk_alloc_allowed) {
   ...
} else {
   ...
}


> +
>  /*
>   * Initializes Receive Unit.
>   */
> @@ -3641,23 +3676,17 @@ ixgbe_dev_rx_init(struct rte_eth_dev *dev)
>  		buf_size = (uint16_t) ((srrctl & IXGBE_SRRCTL_BSIZEPKT_MASK) <<
>  				       IXGBE_SRRCTL_BSIZEPKT_SHIFT);
> 
> -		if (dev->data->dev_conf.rxmode.enable_scatter ||
> -		    /* It adds dual VLAN length for supporting dual VLAN */
> -		    (dev->data->dev_conf.rxmode.max_rx_pkt_len +
> -				2 * IXGBE_VLAN_TAG_SIZE) > buf_size){
> -			if (!dev->data->scattered_rx)
> -				PMD_INIT_LOG(DEBUG, "forcing scatter mode");
> +		/* It adds dual VLAN length for supporting dual VLAN */
> +		if (dev->data->dev_conf.rxmode.max_rx_pkt_len +
> +					    2 * IXGBE_VLAN_TAG_SIZE > buf_size)
>  			dev->data->scattered_rx = 1;
> -#ifdef RTE_IXGBE_INC_VECTOR
> -			if (rte_is_power_of_2(rxq->nb_rx_desc))
> -				dev->rx_pkt_burst =
> -					ixgbe_recv_scattered_pkts_vec;
> -			else
> -#endif
> -				dev->rx_pkt_burst = ixgbe_recv_scattered_pkts;
> -		}
>  	}
> 
> +	if (dev->data->dev_conf.rxmode.enable_scatter)
> +		dev->data->scattered_rx = 1;
> +
> +	set_rx_function(dev);
> +
>  	/*
>  	 * Device configured with multiple RX queues.
>  	 */
> @@ -3933,7 +3962,7 @@ ixgbe_dev_rx_queue_stop(struct rte_eth_dev *dev, uint16_t rx_queue_id)
>  		rte_delay_us(RTE_IXGBE_WAIT_100_US);
> 
>  		ixgbe_rx_queue_release_mbufs(rxq);
> -		ixgbe_reset_rx_queue(rxq);
> +		ixgbe_reset_rx_queue(hw, rxq);
>  	} else
>  		return -1;
> 
> @@ -4289,3 +4318,31 @@ ixgbevf_dev_rxtx_start(struct rte_eth_dev *dev)
> 
>  	}
>  }
> +
> +/* Stubs needed for linkage when CONFIG_RTE_IXGBE_INC_VECTOR is set to 'n' */
> +#ifndef RTE_IXGBE_INC_VECTOR

Instead of ifndef above, can these function below be defined with _attribute__ ((weak))?

> +int ixgbe_rx_vec_condition_check(
> +	struct rte_eth_dev __rte_unused *dev)
> +{
> +	return -1;
> +}
> +
> +uint16_t
> +ixgbe_recv_pkts_vec(void __rte_unused *rx_queue,
> +		    struct rte_mbuf __rte_unused **rx_pkts,
> +		    uint16_t __rte_unused nb_pkts)
> +{
> +	return 0;
> +}
> +
> +uint16_t ixgbe_recv_scattered_pkts_vec(void __rte_unused *rx_queue,
> +	struct rte_mbuf __rte_unused **rx_pkts, uint16_t __rte_unused nb_pkts)
> +{
> +	return 0;
> +}
> +
> +int ixgbe_rxq_vec_setup(struct igb_rx_queue __rte_unused *rxq)
> +{
> +	return -1;
> +}
> +#endif
> diff --git a/lib/librte_pmd_ixgbe/ixgbe_rxtx.h b/lib/librte_pmd_ixgbe/ixgbe_rxtx.h
> index 329007c..bbe5ff3 100644
> --- a/lib/librte_pmd_ixgbe/ixgbe_rxtx.h
> +++ b/lib/librte_pmd_ixgbe/ixgbe_rxtx.h
> @@ -255,16 +255,32 @@ struct ixgbe_txq_ops {
>   */
>  void set_tx_function(struct rte_eth_dev *dev, struct igb_tx_queue *txq);
> 
> -#ifdef RTE_IXGBE_INC_VECTOR
> +/**
> + * Sets the rx_pkt_burst callback in the ixgbe rte_eth_dev instance.
> + *
> + * Sets the callback based on the device parameters:
> + *  - ixgbe_hw.rx_bulk_alloc_allowed
> + *  - rte_eth_dev_data.scattered_rx
> + *  - rte_eth_dev_data.lro
> + *  - conditions checked in ixgbe_rx_vec_condition_check()
> + *
> + *  This means that the parameters above have to be configured prior to calling
> + *  to this function.
> + *
> + * @dev rte_eth_dev handle
> + */
> +void set_rx_function(struct rte_eth_dev *dev);
> +
>  uint16_t ixgbe_recv_pkts_vec(void *rx_queue, struct rte_mbuf **rx_pkts,
>  		uint16_t nb_pkts);
>  uint16_t ixgbe_recv_scattered_pkts_vec(void *rx_queue,
>  		struct rte_mbuf **rx_pkts, uint16_t nb_pkts);
> +int ixgbe_rx_vec_condition_check(struct rte_eth_dev *dev);
> +int ixgbe_rxq_vec_setup(struct igb_rx_queue *rxq);


> +#ifdef RTE_IXGBE_INC_VECTOR

Please add an empty line(s) around 'ifdef' -  makes it much easier to read.

>  uint16_t ixgbe_xmit_pkts_vec(void *tx_queue, struct rte_mbuf **tx_pkts,
>  		uint16_t nb_pkts);
>  int ixgbe_txq_vec_setup(struct igb_tx_queue *txq);
> -int ixgbe_rxq_vec_setup(struct igb_rx_queue *rxq);
> -int ixgbe_rx_vec_condition_check(struct rte_eth_dev *dev);
>  #endif
> 
>  #endif
> --
> 2.1.0