When using RSS, the number of rxqs has to be a power of two.
This is a problem because there is no API is dpdk that makes
the application aware of that.
A good compromise is to allow the application to request a
number of rxqs that is not a power of 2, but having inactive
queues that will never receive packets. In this configuration,
a warning will be issued to users to let them know that
this is not an optimal configuration.
Signed-off-by: Olivier Matz <olivier.matz at 6wind.com>
---
drivers/net/mlx4/mlx4.c | 27 +++++++++++++++++----------
1 file changed, 17 insertions(+), 10 deletions(-)
diff --git a/drivers/net/mlx4/mlx4.c b/drivers/net/mlx4/mlx4.c
index cc4e9aa..eaf06db 100644
--- a/drivers/net/mlx4/mlx4.c
+++ b/drivers/net/mlx4/mlx4.c
@@ -698,7 +698,7 @@ txq_cleanup(struct txq *txq);
static int
rxq_setup(struct rte_eth_dev *dev, struct rxq *rxq, uint16_t desc,
- unsigned int socket, const struct rte_eth_rxconf *conf,
+ unsigned int socket, int inactive, const struct rte_eth_rxconf *conf,
struct rte_mempool *mp);
static void
@@ -734,12 +734,12 @@ dev_configure(struct rte_eth_dev *dev)
}
if (rxqs_n == priv->rxqs_n)
return 0;
- if ((rxqs_n & (rxqs_n - 1)) != 0) {
- ERROR("%p: invalid number of RX queues (%u),"
- " must be a power of 2",
+ if (!rte_is_power_of_2(rxqs_n)) {
+ WARN("%p: number of RX queues (%u), must be a"
+ " power of 2: remaining queues will be inactive",
(void *)dev, rxqs_n);
- return EINVAL;
}
+
INFO("%p: RX queues number update: %u -> %u",
(void *)dev, priv->rxqs_n, rxqs_n);
/* If RSS is enabled, disable it first. */
@@ -775,7 +775,7 @@ dev_configure(struct rte_eth_dev *dev)
priv->rss = 1;
tmp = priv->rxqs_n;
priv->rxqs_n = rxqs_n;
- ret = rxq_setup(dev, &priv->rxq_parent, 0, 0, NULL, NULL);
+ ret = rxq_setup(dev, &priv->rxq_parent, 0, 0, 0, NULL, NULL);
if (!ret)
return 0;
/* Failure, rollback. */
@@ -3466,7 +3466,8 @@ rxq_setup_qp_rss(struct priv *priv, struct ibv_cq *cq,
uint16_t desc,
attr.qpg.qpg_type = IBV_EXP_QPG_PARENT;
/* TSS isn't necessary. */
attr.qpg.parent_attrib.tss_child_count = 0;
- attr.qpg.parent_attrib.rss_child_count = priv->rxqs_n;
+ attr.qpg.parent_attrib.rss_child_count =
+ rte_align32pow2(priv->rxqs_n + 1) >> 1;
DEBUG("initializing parent RSS queue");
} else {
attr.qpg.qpg_type = IBV_EXP_QPG_CHILD_RX;
@@ -3689,6 +3690,9 @@ skip_rtr:
* Number of descriptors to configure in queue.
* @param socket
* NUMA socket on which memory must be allocated.
+ * @param inactive
+ * If true, the queue is disabled because its index is higher or
+ * equal to the real number of queues, which must be a power of 2.
* @param[in] conf
* Thresholds parameters.
* @param mp
@@ -3699,7 +3703,7 @@ skip_rtr:
*/
static int
rxq_setup(struct rte_eth_dev *dev, struct rxq *rxq, uint16_t desc,
- unsigned int socket, const struct rte_eth_rxconf *conf,
+ unsigned int socket, int inactive, const struct rte_eth_rxconf *conf,
struct rte_mempool *mp)
{
struct priv *priv = dev->data->dev_private;
@@ -3800,7 +3804,7 @@ skip_mr:
DEBUG("priv->device_attr.max_sge is %d",
priv->device_attr.max_sge);
#ifdef RSS_SUPPORT
- if (priv->rss)
+ if (priv->rss && !inactive)
tmpl.qp = rxq_setup_qp_rss(priv, tmpl.cq, desc, parent,
tmpl.rd);
else
@@ -3936,6 +3940,7 @@ mlx4_rx_queue_setup(struct rte_eth_dev *dev, uint16_t
idx, uint16_t desc,
{
struct priv *priv = dev->data->dev_private;
struct rxq *rxq = (*priv->rxqs)[idx];
+ int inactive = 0;
int ret;
if (mlx4_is_secondary())
@@ -3967,7 +3972,9 @@ mlx4_rx_queue_setup(struct rte_eth_dev *dev, uint16_t
idx, uint16_t desc,
return -ENOMEM;
}
}
- ret = rxq_setup(dev, rxq, desc, socket, conf, mp);
+ if (idx >= rte_align32pow2(priv->rxqs_n + 1) >> 1)
+ inactive = 1;
+ ret = rxq_setup(dev, rxq, desc, socket, inactive, conf, mp);
if (ret)
rte_free(rxq);
else {
--
2.1.4
