[dpdk-dev] [PATCH v6 1/6] ethdev: allocate max space for internal queue array

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

At queue configure stage always allocate space for maximum possible
number (RTE_MAX_QUEUES_PER_PORT) of queue pointers.
That will allow 'fast' inline functions (eth_rx_burst, etc.) to refer
pointer to internal queue data without extra checking of current number
of configured queues.
That would help in future to hide rte_eth_dev and related structures.
It means that from now on, each ethdev port will always consume:
((2*sizeof(uintptr_t))* RTE_MAX_QUEUES_PER_PORT)
bytes of memory for its queue pointers.
With RTE_MAX_QUEUES_PER_PORT==1024 (default value) it is 16KB per port.

Signed-off-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
---
 lib/ethdev/rte_ethdev.c | 38 +++++---------------------------------
 1 file changed, 5 insertions(+), 33 deletions(-)

diff --git a/lib/ethdev/rte_ethdev.c b/lib/ethdev/rte_ethdev.c
index 5fae7357c8..e446f3b3f8 100644
--- a/lib/ethdev/rte_ethdev.c
+++ b/lib/ethdev/rte_ethdev.c
@@ -919,12 +919,12 @@ static int
 eth_dev_rx_queue_config(struct rte_eth_dev *dev, uint16_t nb_queues)
 {
 	uint16_t old_nb_queues = dev->data->nb_rx_queues;
-	void **rxq;
 	unsigned i;
 
 	if (dev->data->rx_queues == NULL && nb_queues != 0) { /* first time configuration */
 		dev->data->rx_queues = rte_zmalloc("ethdev->rx_queues",
-				sizeof(dev->data->rx_queues[0]) * nb_queues,
+				sizeof(dev->data->rx_queues[0]) *
+				RTE_MAX_QUEUES_PER_PORT,
 				RTE_CACHE_LINE_SIZE);
 		if (dev->data->rx_queues == NULL) {
 			dev->data->nb_rx_queues = 0;
@@ -934,20 +934,6 @@ eth_dev_rx_queue_config(struct rte_eth_dev *dev, uint16_t nb_queues)
 		for (i = nb_queues; i < old_nb_queues; i++)
 			eth_dev_rxq_release(dev, i);
 
-		rxq = dev->data->rx_queues;
-		rxq = rte_realloc(rxq, sizeof(rxq[0]) * nb_queues,
-				RTE_CACHE_LINE_SIZE);
-		if (rxq == NULL)
-			return -(ENOMEM);
-		if (nb_queues > old_nb_queues) {
-			uint16_t new_qs = nb_queues - old_nb_queues;
-
-			memset(rxq + old_nb_queues, 0,
-				sizeof(rxq[0]) * new_qs);
-		}
-
-		dev->data->rx_queues = rxq;
-
 	} else if (dev->data->rx_queues != NULL && nb_queues == 0) {
 		for (i = nb_queues; i < old_nb_queues; i++)
 			eth_dev_rxq_release(dev, i);
@@ -1153,13 +1139,13 @@ static int
 eth_dev_tx_queue_config(struct rte_eth_dev *dev, uint16_t nb_queues)
 {
 	uint16_t old_nb_queues = dev->data->nb_tx_queues;
-	void **txq;
 	unsigned i;
 
 	if (dev->data->tx_queues == NULL && nb_queues != 0) { /* first time configuration */
 		dev->data->tx_queues = rte_zmalloc("ethdev->tx_queues",
-						   sizeof(dev->data->tx_queues[0]) * nb_queues,
-						   RTE_CACHE_LINE_SIZE);
+				sizeof(dev->data->tx_queues[0]) *
+				RTE_MAX_QUEUES_PER_PORT,
+				RTE_CACHE_LINE_SIZE);
 		if (dev->data->tx_queues == NULL) {
 			dev->data->nb_tx_queues = 0;
 			return -(ENOMEM);
@@ -1168,20 +1154,6 @@ eth_dev_tx_queue_config(struct rte_eth_dev *dev, uint16_t nb_queues)
 		for (i = nb_queues; i < old_nb_queues; i++)
 			eth_dev_txq_release(dev, i);
 
-		txq = dev->data->tx_queues;
-		txq = rte_realloc(txq, sizeof(txq[0]) * nb_queues,
-				  RTE_CACHE_LINE_SIZE);
-		if (txq == NULL)
-			return -ENOMEM;
-		if (nb_queues > old_nb_queues) {
-			uint16_t new_qs = nb_queues - old_nb_queues;
-
-			memset(txq + old_nb_queues, 0,
-			       sizeof(txq[0]) * new_qs);
-		}
-
-		dev->data->tx_queues = txq;
-
 	} else if (dev->data->tx_queues != NULL && nb_queues == 0) {
 		for (i = nb_queues; i < old_nb_queues; i++)
 			eth_dev_txq_release(dev, i);
-- 
2.26.3