[v4,2/5] net/i40e: cleanup Tx buffers

Message ID 20191224023906.60789-3-chenxux.di@intel.com (mailing list archive)
State Superseded, archived
Delegated to: xiaolong ye
Headers
Series drivers/net: cleanup Tx buffers |

Checks

Context Check Description
ci/checkpatch success coding style OK
ci/Intel-compilation success Compilation OK

Commit Message

Chenxu Di Dec. 24, 2019, 2:39 a.m. UTC
  Add support to the i40e driver for the API rte_eth_tx_done_cleanup
to force free consumed buffers on Tx ring.

Signed-off-by: Chenxu Di <chenxux.di@intel.com>
---
 drivers/net/i40e/i40e_ethdev.c    |   1 +
 drivers/net/i40e/i40e_ethdev_vf.c |   1 +
 drivers/net/i40e/i40e_rxtx.c      | 122 ++++++++++++++++++++++++++++++
 drivers/net/i40e/i40e_rxtx.h      |   1 +
 4 files changed, 125 insertions(+)
  

Comments

Xing, Beilei Dec. 26, 2019, 8:24 a.m. UTC | #1
> -----Original Message-----
> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Chenxu Di
> Sent: Tuesday, December 24, 2019 10:39 AM
> To: dev@dpdk.org
> Cc: Yang, Qiming <qiming.yang@intel.com>; Di, ChenxuX
> <chenxux.di@intel.com>
> Subject: [dpdk-dev] [PATCH v4 2/5] net/i40e: cleanup Tx buffers
> 
> Add support to the i40e driver for the API rte_eth_tx_done_cleanup to force
> free consumed buffers on Tx ring.
> 
> Signed-off-by: Chenxu Di <chenxux.di@intel.com>
> ---
>  drivers/net/i40e/i40e_ethdev.c    |   1 +
>  drivers/net/i40e/i40e_ethdev_vf.c |   1 +
>  drivers/net/i40e/i40e_rxtx.c      | 122 ++++++++++++++++++++++++++++++
>  drivers/net/i40e/i40e_rxtx.h      |   1 +
>  4 files changed, 125 insertions(+)
> 
> diff --git a/drivers/net/i40e/i40e_ethdev.c b/drivers/net/i40e/i40e_ethdev.c
> index 5999c964b..fad47a942 100644
> --- a/drivers/net/i40e/i40e_ethdev.c
> +++ b/drivers/net/i40e/i40e_ethdev.c
> @@ -522,6 +522,7 @@ static const struct eth_dev_ops i40e_eth_dev_ops = {
>  	.mac_addr_set                 = i40e_set_default_mac_addr,
>  	.mtu_set                      = i40e_dev_mtu_set,
>  	.tm_ops_get                   = i40e_tm_ops_get,
> +	.tx_done_cleanup              = i40e_tx_done_cleanup,
>  };
> 
>  /* store statistics names and its offset in stats structure */ diff --git
> a/drivers/net/i40e/i40e_ethdev_vf.c b/drivers/net/i40e/i40e_ethdev_vf.c
> index 5dba0928b..0ca5417d7 100644
> --- a/drivers/net/i40e/i40e_ethdev_vf.c
> +++ b/drivers/net/i40e/i40e_ethdev_vf.c
> @@ -215,6 +215,7 @@ static const struct eth_dev_ops i40evf_eth_dev_ops = {
>  	.rss_hash_conf_get    = i40evf_dev_rss_hash_conf_get,
>  	.mtu_set              = i40evf_dev_mtu_set,
>  	.mac_addr_set         = i40evf_set_default_mac_addr,
> +	.tx_done_cleanup      = i40e_tx_done_cleanup,
>  };
> 
>  /*
> diff --git a/drivers/net/i40e/i40e_rxtx.c b/drivers/net/i40e/i40e_rxtx.c index
> 17dc8c78f..e75733b8e 100644
> --- a/drivers/net/i40e/i40e_rxtx.c
> +++ b/drivers/net/i40e/i40e_rxtx.c
> @@ -2455,6 +2455,128 @@ i40e_tx_queue_release_mbufs(struct
> i40e_tx_queue *txq)
>  	}
>  }
> 
> +int i40e_tx_done_cleanup(void *q, uint32_t free_cnt) {
> +	struct i40e_tx_queue *txq = (struct i40e_tx_queue *)q;
> +	struct i40e_tx_entry *sw_ring;
> +	volatile struct i40e_tx_desc *txr;
> +	uint16_t tx_first; /* First segment analyzed. */
> +	uint16_t tx_id;    /* Current segment being processed. */
> +	uint16_t tx_last;  /* Last segment in the current packet. */
> +	uint16_t tx_next;  /* First segment of the next packet. */
> +	int count;
> +
> +	if (txq == NULL)
> +		return -ENODEV;
> +
> +	count = 0;
> +	sw_ring = txq->sw_ring;
> +	txr = txq->tx_ring;
> +
> +	/*
> +	 * tx_tail is the last sent packet on the sw_ring. Goto the end
> +	 * of that packet (the last segment in the packet chain) and
> +	 * then the next segment will be the start of the oldest segment
> +	 * in the sw_ring. This is the first packet that will be
> +	 * attempted to be freed.
> +	 */
> +
> +	/* Get last segment in most recently added packet. */
> +	tx_first = sw_ring[txq->tx_tail].last_id;

Should be tx_last more readable here? And then tx_first = sw_ring[tx_last].next_id?

> +
> +	/* Get the next segment, which is the oldest segment in ring. */
> +	tx_first = sw_ring[tx_first].next_id;
> +
> +	/* Set the current index to the first. */
> +	tx_id = tx_first;
> +
> +	/*
> +	 * Loop through each packet. For each packet, verify that an
> +	 * mbuf exists and that the last segment is free. If so, free
> +	 * it and move on.
> +	 */
> +	while (1) {
> +		tx_last = sw_ring[tx_id].last_id;
> +
> +		if (sw_ring[tx_last].mbuf) {
> +			if ((txr[tx_last].cmd_type_offset_bsz &
> +
> 	rte_cpu_to_le_64(I40E_TXD_QW1_DTYPE_MASK)) !=

Is the logic reversed? '!=' means the mbuf is still in use.

> +
> 	rte_cpu_to_le_64(I40E_TX_DESC_DTYPE_DESC_DONE)) {
> +				/*
> +				 * Increment the number of packets
> +				 * freed.
> +				 */
> +				count++;

Should 'count++' be after free mbuf?

> +
> +				/* Get the start of the next packet. */
> +				tx_next = sw_ring[tx_last].next_id;
> +
> +				/*
> +				 * Loop through all segments in a
> +				 * packet.
> +				 */
> +				do {
> +
> 	rte_pktmbuf_free_seg(sw_ring[tx_id].mbuf);
> +					sw_ring[tx_id].mbuf = NULL;
> +					sw_ring[tx_id].last_id = tx_id;
> +
> +					/* Move to next segemnt. */

Typo: segemnt -> segment

> +					tx_id = sw_ring[tx_id].next_id;
> +
> +				} while (tx_id != tx_next);
> +
> +				if (unlikely(count == (int)free_cnt))
> +					break;
> +			} else {
> +				/*
> +				 * mbuf still in use, nothing left to
> +				 * free.
> +				 */
> +				break;
> +			}
> +		} else {
> +			/*
> +			 * There are multiple reasons to be here:
> +			 * 1) All the packets on the ring have been
> +			 *    freed - tx_id is equal to tx_first
> +			 *    and some packets have been freed.
> +			 *    - Done, exit
> +			 * 2) Interfaces has not sent a rings worth of
> +			 *    packets yet, so the segment after tail is
> +			 *    still empty. Or a previous call to this
> +			 *    function freed some of the segments but
> +			 *    not all so there is a hole in the list.
> +			 *    Hopefully this is a rare case.
> +			 *    - Walk the list and find the next mbuf. If
> +			 *      there isn't one, then done.
> +			 */
> +			if (likely(tx_id == tx_first && count != 0))
> +				break;
> +
> +			/*
> +			 * Walk the list and find the next mbuf, if any.
> +			 */
> +			do {
> +				/* Move to next segemnt. */

Typo: segemnt -> segment

> +				tx_id = sw_ring[tx_id].next_id;
> +
> +				if (sw_ring[tx_id].mbuf)
> +					break;
> +
> +			} while (tx_id != tx_first);
> +
> +			/*
> +			 * Determine why previous loop bailed. If there
> +			 * is not an mbuf, done.
> +			 */
> +			if (sw_ring[tx_id].mbuf == NULL)
> +				break;
> +		}
> +	}
> +
> +	return count;
> +}
> +
>  void
>  i40e_reset_tx_queue(struct i40e_tx_queue *txq)  { diff --git
> a/drivers/net/i40e/i40e_rxtx.h b/drivers/net/i40e/i40e_rxtx.h index
> 2106bb355..8f11f011a 100644
> --- a/drivers/net/i40e/i40e_rxtx.h
> +++ b/drivers/net/i40e/i40e_rxtx.h
> @@ -212,6 +212,7 @@ void i40e_dev_free_queues(struct rte_eth_dev *dev);
> void i40e_reset_rx_queue(struct i40e_rx_queue *rxq);  void
> i40e_reset_tx_queue(struct i40e_tx_queue *txq);  void
> i40e_tx_queue_release_mbufs(struct i40e_tx_queue *txq);
> +int i40e_tx_done_cleanup(void *txq, uint32_t free_cnt);
>  int i40e_alloc_rx_queue_mbufs(struct i40e_rx_queue *rxq);  void
> i40e_rx_queue_release_mbufs(struct i40e_rx_queue *rxq);
> 
> --
> 2.17.1
  

Patch

diff --git a/drivers/net/i40e/i40e_ethdev.c b/drivers/net/i40e/i40e_ethdev.c
index 5999c964b..fad47a942 100644
--- a/drivers/net/i40e/i40e_ethdev.c
+++ b/drivers/net/i40e/i40e_ethdev.c
@@ -522,6 +522,7 @@  static const struct eth_dev_ops i40e_eth_dev_ops = {
 	.mac_addr_set                 = i40e_set_default_mac_addr,
 	.mtu_set                      = i40e_dev_mtu_set,
 	.tm_ops_get                   = i40e_tm_ops_get,
+	.tx_done_cleanup              = i40e_tx_done_cleanup,
 };
 
 /* store statistics names and its offset in stats structure */
diff --git a/drivers/net/i40e/i40e_ethdev_vf.c b/drivers/net/i40e/i40e_ethdev_vf.c
index 5dba0928b..0ca5417d7 100644
--- a/drivers/net/i40e/i40e_ethdev_vf.c
+++ b/drivers/net/i40e/i40e_ethdev_vf.c
@@ -215,6 +215,7 @@  static const struct eth_dev_ops i40evf_eth_dev_ops = {
 	.rss_hash_conf_get    = i40evf_dev_rss_hash_conf_get,
 	.mtu_set              = i40evf_dev_mtu_set,
 	.mac_addr_set         = i40evf_set_default_mac_addr,
+	.tx_done_cleanup      = i40e_tx_done_cleanup,
 };
 
 /*
diff --git a/drivers/net/i40e/i40e_rxtx.c b/drivers/net/i40e/i40e_rxtx.c
index 17dc8c78f..e75733b8e 100644
--- a/drivers/net/i40e/i40e_rxtx.c
+++ b/drivers/net/i40e/i40e_rxtx.c
@@ -2455,6 +2455,128 @@  i40e_tx_queue_release_mbufs(struct i40e_tx_queue *txq)
 	}
 }
 
+int i40e_tx_done_cleanup(void *q, uint32_t free_cnt)
+{
+	struct i40e_tx_queue *txq = (struct i40e_tx_queue *)q;
+	struct i40e_tx_entry *sw_ring;
+	volatile struct i40e_tx_desc *txr;
+	uint16_t tx_first; /* First segment analyzed. */
+	uint16_t tx_id;    /* Current segment being processed. */
+	uint16_t tx_last;  /* Last segment in the current packet. */
+	uint16_t tx_next;  /* First segment of the next packet. */
+	int count;
+
+	if (txq == NULL)
+		return -ENODEV;
+
+	count = 0;
+	sw_ring = txq->sw_ring;
+	txr = txq->tx_ring;
+
+	/*
+	 * tx_tail is the last sent packet on the sw_ring. Goto the end
+	 * of that packet (the last segment in the packet chain) and
+	 * then the next segment will be the start of the oldest segment
+	 * in the sw_ring. This is the first packet that will be
+	 * attempted to be freed.
+	 */
+
+	/* Get last segment in most recently added packet. */
+	tx_first = sw_ring[txq->tx_tail].last_id;
+
+	/* Get the next segment, which is the oldest segment in ring. */
+	tx_first = sw_ring[tx_first].next_id;
+
+	/* Set the current index to the first. */
+	tx_id = tx_first;
+
+	/*
+	 * Loop through each packet. For each packet, verify that an
+	 * mbuf exists and that the last segment is free. If so, free
+	 * it and move on.
+	 */
+	while (1) {
+		tx_last = sw_ring[tx_id].last_id;
+
+		if (sw_ring[tx_last].mbuf) {
+			if ((txr[tx_last].cmd_type_offset_bsz &
+				rte_cpu_to_le_64(I40E_TXD_QW1_DTYPE_MASK)) !=
+				rte_cpu_to_le_64(I40E_TX_DESC_DTYPE_DESC_DONE)) {
+				/*
+				 * Increment the number of packets
+				 * freed.
+				 */
+				count++;
+
+				/* Get the start of the next packet. */
+				tx_next = sw_ring[tx_last].next_id;
+
+				/*
+				 * Loop through all segments in a
+				 * packet.
+				 */
+				do {
+					rte_pktmbuf_free_seg(sw_ring[tx_id].mbuf);
+					sw_ring[tx_id].mbuf = NULL;
+					sw_ring[tx_id].last_id = tx_id;
+
+					/* Move to next segemnt. */
+					tx_id = sw_ring[tx_id].next_id;
+
+				} while (tx_id != tx_next);
+
+				if (unlikely(count == (int)free_cnt))
+					break;
+			} else {
+				/*
+				 * mbuf still in use, nothing left to
+				 * free.
+				 */
+				break;
+			}
+		} else {
+			/*
+			 * There are multiple reasons to be here:
+			 * 1) All the packets on the ring have been
+			 *    freed - tx_id is equal to tx_first
+			 *    and some packets have been freed.
+			 *    - Done, exit
+			 * 2) Interfaces has not sent a rings worth of
+			 *    packets yet, so the segment after tail is
+			 *    still empty. Or a previous call to this
+			 *    function freed some of the segments but
+			 *    not all so there is a hole in the list.
+			 *    Hopefully this is a rare case.
+			 *    - Walk the list and find the next mbuf. If
+			 *      there isn't one, then done.
+			 */
+			if (likely(tx_id == tx_first && count != 0))
+				break;
+
+			/*
+			 * Walk the list and find the next mbuf, if any.
+			 */
+			do {
+				/* Move to next segemnt. */
+				tx_id = sw_ring[tx_id].next_id;
+
+				if (sw_ring[tx_id].mbuf)
+					break;
+
+			} while (tx_id != tx_first);
+
+			/*
+			 * Determine why previous loop bailed. If there
+			 * is not an mbuf, done.
+			 */
+			if (sw_ring[tx_id].mbuf == NULL)
+				break;
+		}
+	}
+
+	return count;
+}
+
 void
 i40e_reset_tx_queue(struct i40e_tx_queue *txq)
 {
diff --git a/drivers/net/i40e/i40e_rxtx.h b/drivers/net/i40e/i40e_rxtx.h
index 2106bb355..8f11f011a 100644
--- a/drivers/net/i40e/i40e_rxtx.h
+++ b/drivers/net/i40e/i40e_rxtx.h
@@ -212,6 +212,7 @@  void i40e_dev_free_queues(struct rte_eth_dev *dev);
 void i40e_reset_rx_queue(struct i40e_rx_queue *rxq);
 void i40e_reset_tx_queue(struct i40e_tx_queue *txq);
 void i40e_tx_queue_release_mbufs(struct i40e_tx_queue *txq);
+int i40e_tx_done_cleanup(void *txq, uint32_t free_cnt);
 int i40e_alloc_rx_queue_mbufs(struct i40e_rx_queue *rxq);
 void i40e_rx_queue_release_mbufs(struct i40e_rx_queue *rxq);