[dpdk-dev] [PATCH] net/mlx5: fix info about Rx descriptors for MPRQ

[dpdk-dev] [PATCH] net/mlx5: fix info about Rx descriptors for MPRQ

[Alexander Kozyrev]

Numbers of descriptors configured is returned to a user
via rxq_info_get API. This number is incorrect for MPRQ.
For SPRQ this number matches the number of mbufs allocated.
For MPRQ we have fewer external MPRQ buffers that can hold
multiple packets in strides os this big buffer. Take that
into account and return teh number of MPRQ buffers multiplied
by the number of strides in this case.

Fixes: 26f1bae837 ("net/mlx5: add Rx/Tx burst mode info")
Cc: stable@dpdk.org

Signed-off-by: Alexander Kozyrev <akozyrev@nvidia.com>
---
 drivers/net/mlx5/mlx5_rxtx.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/net/mlx5/mlx5_rxtx.c b/drivers/net/mlx5/mlx5_rxtx.c
index 3aee8d4def..f90124a2aa 100644
--- a/drivers/net/mlx5/mlx5_rxtx.c
+++ b/drivers/net/mlx5/mlx5_rxtx.c
@@ -566,7 +566,9 @@ mlx5_rxq_info_get(struct rte_eth_dev *dev, uint16_t rx_queue_id,
 	qinfo->conf.rx_deferred_start = rxq_ctrl ? 0 : 1;
 	qinfo->conf.offloads = dev->data->dev_conf.rxmode.offloads;
 	qinfo->scattered_rx = dev->data->scattered_rx;
-	qinfo->nb_desc = 1 << rxq->elts_n;
+	qinfo->nb_desc = mlx5_rxq_mprq_enabled(&rxq_ctrl->rxq) ?
+		(1 << rxq->elts_n) * (1 << rxq->strd_num_n) :
+		(1 << rxq->elts_n);
 }
 
 /**
-- 
2.24.1

[dpdk-dev] [PATCH v2] net/mlx5: fix info about Rx descriptors for MPRQ

[Alexander Kozyrev]

The number of descriptors configured is returned to a user
via the rxq_info_get API. This number is incorrect for MPRQ.
For SPRQ this number matches the number of mbufs allocated.
For MPRQ we have fewer external MPRQ buffers that can hold
multiple packets in strides of this big buffer. Take that
into account and return the number of MPRQ buffers multiplied
by the number of strides in this case.

Fixes: 26f1bae837 ("net/mlx5: add Rx/Tx burst mode info")
Cc: stable@dpdk.org

Signed-off-by: Alexander Kozyrev <akozyrev@nvidia.com>
---
v1: https://patchwork.dpdk.org/patch/83778/
v2: fixed a commit message typo and a coverity issue

 drivers/net/mlx5/mlx5_rxtx.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/net/mlx5/mlx5_rxtx.c b/drivers/net/mlx5/mlx5_rxtx.c
index 3aee8d4def..c540849da2 100644
--- a/drivers/net/mlx5/mlx5_rxtx.c
+++ b/drivers/net/mlx5/mlx5_rxtx.c
@@ -556,7 +556,7 @@ mlx5_rxq_info_get(struct rte_eth_dev *dev, uint16_t rx_queue_id,
 
 	if (!rxq)
 		return;
-	qinfo->mp = mlx5_rxq_mprq_enabled(&rxq_ctrl->rxq) ?
+	qinfo->mp = mlx5_rxq_mprq_enabled(rxq) ?
 					rxq->mprq_mp : rxq->mp;
 	qinfo->conf.rx_thresh.pthresh = 0;
 	qinfo->conf.rx_thresh.hthresh = 0;
@@ -566,7 +566,9 @@ mlx5_rxq_info_get(struct rte_eth_dev *dev, uint16_t rx_queue_id,
 	qinfo->conf.rx_deferred_start = rxq_ctrl ? 0 : 1;
 	qinfo->conf.offloads = dev->data->dev_conf.rxmode.offloads;
 	qinfo->scattered_rx = dev->data->scattered_rx;
-	qinfo->nb_desc = 1 << rxq->elts_n;
+	qinfo->nb_desc = mlx5_rxq_mprq_enabled(rxq) ?
+		(1 << rxq->elts_n) * (1 << rxq->strd_num_n) :
+		(1 << rxq->elts_n);
 }
 
 /**
-- 
2.24.1

Re: [dpdk-dev] [PATCH v2] net/mlx5: fix info about Rx descriptors for MPRQ

[Slava Ovsiienko]

> -----Original Message-----
> From: Alexander Kozyrev <akozyrev@nvidia.com>
> Sent: Sunday, November 8, 2020 6:28
> To: dev@dpdk.org
> Cc: Raslan Darawsheh <rasland@nvidia.com>; Matan Azrad
> <matan@nvidia.com>; Slava Ovsiienko <viacheslavo@nvidia.com>;
> stable@dpdk.org
> Subject: [PATCH v2] net/mlx5: fix info about Rx descriptors for MPRQ
> 
> The number of descriptors configured is returned to a user via the rxq_info_get
> API. This number is incorrect for MPRQ.
> For SPRQ this number matches the number of mbufs allocated.
> For MPRQ we have fewer external MPRQ buffers that can hold multiple
> packets in strides of this big buffer. Take that into account and return the
> number of MPRQ buffers multiplied by the number of strides in this case.
> 
> Fixes: 26f1bae837 ("net/mlx5: add Rx/Tx burst mode info")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Alexander Kozyrev <akozyrev@nvidia.com>
Acked-by: Viacheslav Ovsiienko <viacheslavo@nvidia.com>

Re: [dpdk-dev] [PATCH v2] net/mlx5: fix info about Rx descriptors for MPRQ

[Thomas Monjalon]

> > The number of descriptors configured is returned to a user via the rxq_info_get
> > API. This number is incorrect for MPRQ.
> > For SPRQ this number matches the number of mbufs allocated.
> > For MPRQ we have fewer external MPRQ buffers that can hold multiple
> > packets in strides of this big buffer. Take that into account and return the
> > number of MPRQ buffers multiplied by the number of strides in this case.
> > 
> > Fixes: 26f1bae837 ("net/mlx5: add Rx/Tx burst mode info")
> > Cc: stable@dpdk.org
> > 
> > Signed-off-by: Alexander Kozyrev <akozyrev@nvidia.com>
> Acked-by: Viacheslav Ovsiienko <viacheslavo@nvidia.com>

Applied in next-net-mlx, thanks.