[dpdk-dev] [PATCH] net/bnx2x: Fix transmit queue free threshold

[dpdk-dev] [PATCH] net/bnx2x: Fix transmit queue free threshold

[Charles (Chas) Williams]

The default tx_free_thresh is potentially larger than the allocated queue
which will result in TX queue cleanup never happening.  To fix this,
lower the default free threshold and ensure that the free threshold is
never greater than the maximum outstanding transmit buffers.

Fixes: 827ed2a118cc ("net/bnx2x: restructure Tx routine")

Signed-off-by: Chas Williams <ciwillia@brocade.com>
---
 drivers/net/bnx2x/bnx2x_rxtx.c | 2 ++
 drivers/net/bnx2x/bnx2x_rxtx.h | 2 +-
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/net/bnx2x/bnx2x_rxtx.c b/drivers/net/bnx2x/bnx2x_rxtx.c
index 170e48f..adf0309 100644
--- a/drivers/net/bnx2x/bnx2x_rxtx.c
+++ b/drivers/net/bnx2x/bnx2x_rxtx.c
@@ -273,6 +273,8 @@ bnx2x_dev_tx_queue_setup(struct rte_eth_dev *dev,
 
 	txq->tx_free_thresh = tx_conf->tx_free_thresh ?
 		tx_conf->tx_free_thresh : DEFAULT_TX_FREE_THRESH;
+	txq->tx_free_thresh = min(txq->tx_free_thresh,
+				  txq->nb_tx_desc - BDS_PER_TX_PKT);
 
 	PMD_INIT_LOG(DEBUG, "fp[%02d] req_bd=%u, thresh=%u, usable_bd=%lu, "
 		     "total_bd=%lu, tx_pages=%u",
diff --git a/drivers/net/bnx2x/bnx2x_rxtx.h b/drivers/net/bnx2x/bnx2x_rxtx.h
index dd251aa..2e38ec2 100644
--- a/drivers/net/bnx2x/bnx2x_rxtx.h
+++ b/drivers/net/bnx2x/bnx2x_rxtx.h
@@ -11,7 +11,7 @@
 #ifndef _BNX2X_RXTX_H_
 #define _BNX2X_RXTX_H_
 
-#define DEFAULT_TX_FREE_THRESH   512
+#define DEFAULT_TX_FREE_THRESH   64
 #define RTE_PMD_BNX2X_TX_MAX_BURST 1
 
 /**
-- 
2.1.4

Re: [dpdk-dev] [PATCH] net/bnx2x: Fix transmit queue free threshold

[Harish Patil]

>
>The default tx_free_thresh is potentially larger than the allocated queue
>which will result in TX queue cleanup never happening.  To fix this,
>lower the default free threshold and ensure that the free threshold is
>never greater than the maximum outstanding transmit buffers.
>
>Fixes: 827ed2a118cc ("net/bnx2x: restructure Tx routine")
>
>Signed-off-by: Chas Williams <ciwillia@brocade.com>
>---
> drivers/net/bnx2x/bnx2x_rxtx.c | 2 ++
> drivers/net/bnx2x/bnx2x_rxtx.h | 2 +-
> 2 files changed, 3 insertions(+), 1 deletion(-)
>
>diff --git a/drivers/net/bnx2x/bnx2x_rxtx.c
>b/drivers/net/bnx2x/bnx2x_rxtx.c
>index 170e48f..adf0309 100644
>--- a/drivers/net/bnx2x/bnx2x_rxtx.c
>+++ b/drivers/net/bnx2x/bnx2x_rxtx.c
>@@ -273,6 +273,8 @@ bnx2x_dev_tx_queue_setup(struct rte_eth_dev *dev,
> 
> 	txq->tx_free_thresh = tx_conf->tx_free_thresh ?
> 		tx_conf->tx_free_thresh : DEFAULT_TX_FREE_THRESH;
>+	txq->tx_free_thresh = min(txq->tx_free_thresh,
>+				  txq->nb_tx_desc - BDS_PER_TX_PKT);
> 
> 	PMD_INIT_LOG(DEBUG, "fp[%02d] req_bd=%u, thresh=%u, usable_bd=%lu, "
> 		     "total_bd=%lu, tx_pages=%u",
>diff --git a/drivers/net/bnx2x/bnx2x_rxtx.h
>b/drivers/net/bnx2x/bnx2x_rxtx.h
>index dd251aa..2e38ec2 100644
>--- a/drivers/net/bnx2x/bnx2x_rxtx.h
>+++ b/drivers/net/bnx2x/bnx2x_rxtx.h
>@@ -11,7 +11,7 @@
> #ifndef _BNX2X_RXTX_H_
> #define _BNX2X_RXTX_H_
> 
>-#define DEFAULT_TX_FREE_THRESH   512
>+#define DEFAULT_TX_FREE_THRESH   64
> #define RTE_PMD_BNX2X_TX_MAX_BURST 1
> 
> /**
>-- 
>2.1.4
>
>

Acked-by: Harish Patil <harish.patil@qlogic.com>

Re: [dpdk-dev] [PATCH] net/bnx2x: Fix transmit queue free threshold

[Ferruh Yigit]

On 2/23/2017 12:26 AM, Harish Patil wrote:
>>
>> The default tx_free_thresh is potentially larger than the allocated queue
>> which will result in TX queue cleanup never happening.  To fix this,
>> lower the default free threshold and ensure that the free threshold is
>> never greater than the maximum outstanding transmit buffers.
>>
>> Fixes: 827ed2a118cc ("net/bnx2x: restructure Tx routine")
>>
>> Signed-off-by: Chas Williams <ciwillia@brocade.com>

> Acked-by: Harish Patil <harish.patil@qlogic.com>

    net/bnx2x: fix transmit queue free threshold

    Cc: stable@dpdk.org

Applied to dpdk-next-net/master, thanks.