[dpdk-dev] [PATCH v2 1/1] net/octeontx2: fix optimal default sqe buffer count

[<vattunuru@marvell.com>]

From: Vamsi Attunuru <vattunuru@marvell.com>

Patch extends minimum supported max_sqb_count devarg value
such that it can limit the max sqb count to 8 buffers and
also defines NIX_DEF_SQB and uses it to compute the number
of sqe buffers required for the egress traffic.

NIX_DEF_SQB is defined as 16 which is optimal across multiple
octeontx2 platforms to scale up the performance proportional
to the corresponding port/queue to lcore mappings.

Fixes: fb0198b7dc07 ("net/octeontx2: add devargs parsing functions")

Signed-off-by: Vamsi Attunuru <vattunuru@marvell.com>
---
V2 Changes:
* Minor correction in commit message. 

 drivers/net/octeontx2/otx2_ethdev.c         | 2 +-
 drivers/net/octeontx2/otx2_ethdev.h         | 3 ++-
 drivers/net/octeontx2/otx2_ethdev_devargs.c | 2 +-
 3 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/net/octeontx2/otx2_ethdev.c b/drivers/net/octeontx2/otx2_ethdev.c
index 3fb7bd9..3615ed2 100644
--- a/drivers/net/octeontx2/otx2_ethdev.c
+++ b/drivers/net/octeontx2/otx2_ethdev.c
@@ -810,7 +810,7 @@ nix_alloc_sqb_pool(int port, struct otx2_eth_txq *txq, uint16_t nb_desc)
 
 	nb_sqb_bufs = nb_desc / sqes_per_sqb;
 	/* Clamp up to devarg passed SQB count */
-	nb_sqb_bufs =  RTE_MIN(dev->max_sqb_count, RTE_MAX(NIX_MIN_SQB,
+	nb_sqb_bufs =  RTE_MIN(dev->max_sqb_count, RTE_MAX(NIX_DEF_SQB,
 			      nb_sqb_bufs + NIX_SQB_LIST_SPACE));
 
 	txq->sqb_pool = rte_mempool_create_empty(name, NIX_MAX_SQB, blk_sz,
diff --git a/drivers/net/octeontx2/otx2_ethdev.h b/drivers/net/octeontx2/otx2_ethdev.h
index 720386f..027b909 100644
--- a/drivers/net/octeontx2/otx2_ethdev.h
+++ b/drivers/net/octeontx2/otx2_ethdev.h
@@ -66,7 +66,8 @@
 	(NIX_MAX_FRS - NIX_L2_OVERHEAD)
 
 #define NIX_MAX_SQB			512
-#define NIX_MIN_SQB			32
+#define NIX_DEF_SQB			16
+#define NIX_MIN_SQB			8
 #define NIX_SQB_LIST_SPACE		2
 #define NIX_RSS_RETA_SIZE_MAX		256
 /* Group 0 will be used for RSS, 1 -7 will be used for rte_flow RSS action*/
diff --git a/drivers/net/octeontx2/otx2_ethdev_devargs.c b/drivers/net/octeontx2/otx2_ethdev_devargs.c
index 85e7e31..7dc6e92 100644
--- a/drivers/net/octeontx2/otx2_ethdev_devargs.c
+++ b/drivers/net/octeontx2/otx2_ethdev_devargs.c
@@ -160,6 +160,6 @@ RTE_PMD_REGISTER_PARAM_STRING(net_octeontx2,
 			      OTX2_RSS_RETA_SIZE "=<64|128|256>"
 			      OTX2_PTYPE_DISABLE "=1"
 			      OTX2_SCL_ENABLE "=1"
-			      OTX2_MAX_SQB_COUNT "=<32-512>"
+			      OTX2_MAX_SQB_COUNT "=<8-512>"
 			      OTX2_FLOW_PREALLOC_SIZE "=<1-32>"
 			      OTX2_FLOW_MAX_PRIORITY "=<1-32>");
-- 
2.8.4