[dpdk-dev] [PATCH v7 3/4] net/ixgbe: cleanup Tx buffers

[Ananyev, Konstantin]

Hi Chenxu,

Good progress wih _full_version, but still some issues remains I think.
More comments inline.
Konstantin

> 
> Signed-off-by: Chenxu Di <chenxux.di at intel.com>
> ---
>  drivers/net/ixgbe/ixgbe_ethdev.c |   4 +
>  drivers/net/ixgbe/ixgbe_rxtx.c   | 156 ++++++++++++++++++++++++++++++-
>  drivers/net/ixgbe/ixgbe_rxtx.h   |  10 ++
>  3 files changed, 169 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ixgbe/ixgbe_ethdev.c b/drivers/net/ixgbe/ixgbe_ethdev.c
> index 2c6fd0f13..668c36188 100644
> --- a/drivers/net/ixgbe/ixgbe_ethdev.c
> +++ b/drivers/net/ixgbe/ixgbe_ethdev.c
> @@ -601,6 +601,7 @@ static const struct eth_dev_ops ixgbe_eth_dev_ops = {
>  	.udp_tunnel_port_add  = ixgbe_dev_udp_tunnel_port_add,
>  	.udp_tunnel_port_del  = ixgbe_dev_udp_tunnel_port_del,
>  	.tm_ops_get           = ixgbe_tm_ops_get,
> +	.tx_done_cleanup      = ixgbe_tx_done_cleanup,
>  };
> 
>  /*
> @@ -649,6 +650,7 @@ static const struct eth_dev_ops ixgbevf_eth_dev_ops = {
>  	.reta_query           = ixgbe_dev_rss_reta_query,
>  	.rss_hash_update      = ixgbe_dev_rss_hash_update,
>  	.rss_hash_conf_get    = ixgbe_dev_rss_hash_conf_get,
> +	.tx_done_cleanup      = ixgbe_tx_done_cleanup,
>  };
> 
>  /* store statistics names and its offset in stats structure */
> @@ -1101,6 +1103,7 @@ eth_ixgbe_dev_init(struct rte_eth_dev *eth_dev, void *init_params __rte_unused)
>  	eth_dev->rx_pkt_burst = &ixgbe_recv_pkts;
>  	eth_dev->tx_pkt_burst = &ixgbe_xmit_pkts;
>  	eth_dev->tx_pkt_prepare = &ixgbe_prep_pkts;
> +	ixgbe_set_tx_done_cleanup_func(ixgbe_tx_done_cleanup_scalar);
> 
>  	/*
>  	 * For secondary processes, we don't initialise any further as primary
> @@ -1580,6 +1583,7 @@ eth_ixgbevf_dev_init(struct rte_eth_dev *eth_dev)
>  	eth_dev->dev_ops = &ixgbevf_eth_dev_ops;
>  	eth_dev->rx_pkt_burst = &ixgbe_recv_pkts;
>  	eth_dev->tx_pkt_burst = &ixgbe_xmit_pkts;
> +	ixgbe_set_tx_done_cleanup_func(ixgbe_tx_done_cleanup_scalar);
> 
>  	/* for secondary processes, we don't initialise any further as primary
>  	 * has already done this work. Only check we don't need a different
> diff --git a/drivers/net/ixgbe/ixgbe_rxtx.c b/drivers/net/ixgbe/ixgbe_rxtx.c
> index fa572d184..122dae425 100644
> --- a/drivers/net/ixgbe/ixgbe_rxtx.c
> +++ b/drivers/net/ixgbe/ixgbe_rxtx.c
> @@ -92,6 +92,8 @@ uint16_t ixgbe_xmit_fixed_burst_vec(void *tx_queue, struct rte_mbuf **tx_pkts,
>  				    uint16_t nb_pkts);
>  #endif
> 
> +static ixgbe_tx_done_cleanup_t ixgbe_tx_done_cleanup_op;

You can't have just one static variable here.
There could be several ixgbe devices and they could be configured in a different way.
I.E. txpkt_burst() is per device, so tx_done_cleanup() also has to be per device.
Probably the easiest way is to add new entry for tx_done_cleanup into struct ixgbe_txq_ops,
and set it properly in ixgbe_set_tx_function().

> +
>  /*********************************************************************
>   *
>   *  TX functions
> @@ -2306,6 +2308,152 @@ ixgbe_tx_queue_release_mbufs(struct ixgbe_tx_queue *txq)
>  	}
>  }
> 
> +int
> +ixgbe_tx_done_cleanup_scalar(struct ixgbe_tx_queue *txq, uint32_t free_cnt)

As a nit I would change _scalar to _full or so.

> +{
> +	uint32_t pkt_cnt;
> +	uint16_t i;
> +	uint16_t tx_last;
> +	uint16_t tx_id;
> +	uint16_t nb_tx_to_clean;
> +	uint16_t nb_tx_free_last;
> +	struct ixgbe_tx_entry *swr_ring = txq->sw_ring;
> +
> +	/* Start free mbuf from the next of tx_tail */
> +	tx_last = txq->tx_tail;
> +	tx_id  = swr_ring[tx_last].next_id;
> +
> +	if (txq->nb_tx_free == 0)
> +		if (ixgbe_xmit_cleanup(txq))


As a nit it could be just if (ixgbe_set_tx_function && ixgbe_xmit_cleanup(txq))

> +			return 0;
> +
> +	nb_tx_to_clean = txq->nb_tx_free;
> +	nb_tx_free_last = txq->nb_tx_free;
> +	if (!free_cnt)
> +		free_cnt = txq->nb_tx_desc;
> +
> +	/* Loop through swr_ring to count the amount of
> +	 * freeable mubfs and packets.
> +	 */
> +	for (pkt_cnt = 0; pkt_cnt < free_cnt; ) {
> +		for (i = 0; i < nb_tx_to_clean &&
> +			pkt_cnt < free_cnt &&
> +			tx_id != tx_last; i++) {
> +			if (swr_ring[tx_id].mbuf != NULL) {
> +				rte_pktmbuf_free_seg(swr_ring[tx_id].mbuf);
> +				swr_ring[tx_id].mbuf = NULL;
> +
> +				/*
> +				 * last segment in the packet,
> +				 * increment packet count
> +				 */
> +				pkt_cnt += (swr_ring[tx_id].last_id == tx_id);
> +			}
> +
> +			tx_id = swr_ring[tx_id].next_id;
> +		}
> +
> +		if (tx_id == tx_last || txq->tx_rs_thresh
> +			> txq->nb_tx_desc - txq->nb_tx_free)

First condition (tx_id == tx_last) is porbably redundant here.

> +			break;
> +
> +		if (pkt_cnt < free_cnt) {
> +			if (ixgbe_xmit_cleanup(txq))
> +				break;
> +
> +			nb_tx_to_clean = txq->nb_tx_free - nb_tx_free_last;
> +			nb_tx_free_last = txq->nb_tx_free;
> +		}
> +	}
> +
> +	PMD_TX_FREE_LOG(DEBUG,
> +		"Free %u Packets successfully "
> +		"(port=%d queue=%d)",
> +		pkt_cnt, txq->port_id, txq->queue_id);
> +
> +	return (int)pkt_cnt;
> +}
> +
> +int
> +ixgbe_tx_done_cleanup_vec(struct ixgbe_tx_queue *txq __rte_unused,
> +			uint32_t free_cnt __rte_unused)
> +{
> +	return -ENOTSUP;
> +}
> +
> +int
> +ixgbe_tx_done_cleanup_simple(struct ixgbe_tx_queue *txq,
> +			uint32_t free_cnt)
> +{
> +	uint16_t i;
> +	uint16_t tx_first;
> +	uint16_t tx_id;
> +	uint32_t pkt_cnt;
> +	struct ixgbe_tx_entry *swr_ring = txq->sw_ring;


Looks overcomplicated here.
TX simple (and vec) doesn't support mulsti-seg packets, 
So one TXD - one mbuf, and one packet.
And ixgbe_tx_free_bufs() always retunrs/frees either 0 or tx_rs_thresh mbufs/packets.
So it probably can be something like that:

ixgbe_tx_done_cleanup_simple(struct ixgbe_tx_queue *txq,  uint32_t free_cnt)
{
   If (free_cnt == 0)
      free_cnt = txq->nb_desc;
 
   cnt = free_cnt - free_cnt % txq->tx_rs_thesh;
    for (i = 0; i < cnt; i+= n) {
          n = ixgbe_tx_free_bufs(txq);
          if (n == 0)
             break;
    } 
    return i;
}

> +
> +	/* Start free mbuf from tx_first */
> +	tx_first = txq->tx_next_dd - (txq->tx_rs_thresh - 1);
> +	tx_id  = tx_first;
> +
> +	/* while free_cnt is 0,
> +	 * suppose one mbuf per packet,
> +	 * try to free packets as many as possible
> +	 */
> +	if (free_cnt == 0)
> +		free_cnt = txq->nb_tx_desc;
> +
> +	/* Loop through swr_ring to count freeable packets */
> +	for (pkt_cnt = 0; pkt_cnt < free_cnt; ) {
> +		if (txq->nb_tx_desc - txq->nb_tx_free < txq->tx_rs_thresh)
> +			break;
> +
> +		if (!ixgbe_tx_free_bufs(txq))
> +			break;
> +
> +		for (i = 0; i != txq->tx_rs_thresh &&
> +			tx_id != tx_first; i++) {
> +			/* last segment in the packet,
> +			 * increment packet count
> +			 */
> +			pkt_cnt += (tx_id == swr_ring[tx_id].last_id);
> +			tx_id = swr_ring[tx_id].next_id;
> +		}
> +
> +		if (tx_id == tx_first)
> +			break;
> +	}
> +
> +	PMD_TX_FREE_LOG(DEBUG,
> +		"Free %u packets successfully "
> +		"(port=%d queue=%d)",
> +		pkt_cnt, txq->port_id, txq->queue_id);
> +
> +	return (int)pkt_cnt;
> +}
> +
> +int
> +ixgbe_tx_done_cleanup(void *txq, uint32_t free_cnt)
> +{
> +	ixgbe_tx_done_cleanup_t func = ixgbe_get_tx_done_cleanup_func();
> +
> +	if (!func)
> +		return -ENOTSUP;
> +
> +	return func(txq, free_cnt);
> +}
> +
> +void
> +ixgbe_set_tx_done_cleanup_func(ixgbe_tx_done_cleanup_t fn)
> +{
> +	ixgbe_tx_done_cleanup_op = fn;
> +}
> +
> +ixgbe_tx_done_cleanup_t
> +ixgbe_get_tx_done_cleanup_func(void)
> +{
> +	return ixgbe_tx_done_cleanup_op;
> +}
> +
>  static void __attribute__((cold))
>  ixgbe_tx_free_swring(struct ixgbe_tx_queue *txq)
>  {
> @@ -2398,9 +2546,14 @@ ixgbe_set_tx_function(struct rte_eth_dev *dev, struct ixgbe_tx_queue *txq)
>  					ixgbe_txq_vec_setup(txq) == 0)) {
>  			PMD_INIT_LOG(DEBUG, "Vector tx enabled.");
>  			dev->tx_pkt_burst = ixgbe_xmit_pkts_vec;
> -		} else
> +			ixgbe_set_tx_done_cleanup_func(ixgbe_tx_done_cleanup_vec);
> +		} else {
>  #endif
>  		dev->tx_pkt_burst = ixgbe_xmit_pkts_simple;
> +		ixgbe_set_tx_done_cleanup_func(ixgbe_tx_done_cleanup_simple);
> +#ifdef RTE_IXGBE_INC_VECTOR
> +		}
> +#endif
>  	} else {
>  		PMD_INIT_LOG(DEBUG, "Using full-featured tx code path");
>  		PMD_INIT_LOG(DEBUG,
> @@ -2412,6 +2565,7 @@ ixgbe_set_tx_function(struct rte_eth_dev *dev, struct ixgbe_tx_queue *txq)
>  				(unsigned long)RTE_PMD_IXGBE_TX_MAX_BURST);
>  		dev->tx_pkt_burst = ixgbe_xmit_pkts;
>  		dev->tx_pkt_prepare = ixgbe_prep_pkts;
> +		ixgbe_set_tx_done_cleanup_func(ixgbe_tx_done_cleanup_scalar);
>  	}
>  }
> 
> diff --git a/drivers/net/ixgbe/ixgbe_rxtx.h b/drivers/net/ixgbe/ixgbe_rxtx.h
> index 505d344b9..a52597aa9 100644
> --- a/drivers/net/ixgbe/ixgbe_rxtx.h
> +++ b/drivers/net/ixgbe/ixgbe_rxtx.h
> @@ -253,6 +253,8 @@ struct ixgbe_txq_ops {
>  			 IXGBE_ADVTXD_DCMD_DEXT |\
>  			 IXGBE_ADVTXD_DCMD_EOP)
> 
> +typedef int (*ixgbe_tx_done_cleanup_t)(struct ixgbe_tx_queue *txq,
> +				uint32_t free_cnt);
> 
>  /* Takes an ethdev and a queue and sets up the tx function to be used based on
>   * the queue parameters. Used in tx_queue_setup by primary process and then
> @@ -285,6 +287,14 @@ int ixgbe_rx_vec_dev_conf_condition_check(struct rte_eth_dev *dev);
>  int ixgbe_rxq_vec_setup(struct ixgbe_rx_queue *rxq);
>  void ixgbe_rx_queue_release_mbufs_vec(struct ixgbe_rx_queue *rxq);
> 
> +void ixgbe_set_tx_done_cleanup_func(ixgbe_tx_done_cleanup_t fn);
> +ixgbe_tx_done_cleanup_t ixgbe_get_tx_done_cleanup_func(void);
> +
> +int ixgbe_tx_done_cleanup(void *txq, uint32_t free_cnt);
> +int ixgbe_tx_done_cleanup_scalar(struct ixgbe_tx_queue *txq, uint32_t free_cnt);
> +int ixgbe_tx_done_cleanup_vec(struct ixgbe_tx_queue *txq, uint32_t free_cnt);
> +int ixgbe_tx_done_cleanup_simple(struct ixgbe_tx_queue *txq, uint32_t free_cnt);
> +
>  extern const uint32_t ptype_table[IXGBE_PACKET_TYPE_MAX];
>  extern const uint32_t ptype_table_tn[IXGBE_PACKET_TYPE_TN_MAX];
> 
> --
> 2.17.1