[SRU][N:linux-azure][PATCH 1/7] net: mana: Increase the DEF_RX_BUFFERS_PER_QUEUE to 1024

[John Cabaj]

From: Shradha Gupta <shradhagupta at linux.microsoft.com>

BugLink: https://bugs.launchpad.net/bugs/2098508

Through some experiments, we found out that increasing the default
RX buffers count from 512 to 1024, gives slightly better throughput
and significantly reduces the no_wqe_rx errs on the receiver side.
Along with these, other parameters like cpu usage, retrans seg etc
also show some improvement with 1024 value.

Following are some snippets from the experiments

ntttcp tests with 512 Rx buffers
---------------------------------------
connections|  throughput|  no_wqe errs|
---------------------------------------
1          |  40.93Gbps | 123,211     |
16         | 180.15Gbps | 190,120     |
128        | 180.20Gbps | 173,508     |
256        | 180.27Gbps | 189,884     |

ntttcp tests with 1024 Rx buffers
---------------------------------------
connections|  throughput|  no_wqe errs|
---------------------------------------
1          |  44.22Gbps | 19,864      |
16         | 180.19Gbps | 4,430       |
128        | 180.21Gbps | 2,560       |
256        | 180.29Gbps | 1,529       |

So, increasing the default RX buffers per queue count to 1024

Signed-off-by: Shradha Gupta <shradhagupta at linux.microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz at microsoft.com>
Reviewed-by: Pavan Chebbi <pavan.chebbi at broadcom.com>
Link: https://patch.msgid.link/1727667875-29908-1-git-send-email-shradhagupta@linux.microsoft.com
Signed-off-by: Paolo Abeni <pabeni at redhat.com>
(cherry picked from commit e26a0c5d828b225b88f534e2fcf10bf617f85f23)
Signed-off-by: John Cabaj <john.cabaj at canonical.com>
---
 include/net/mana/mana.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/net/mana/mana.h b/include/net/mana/mana.h
index d561e6cd454e..7b2bc8599acf 100644
--- a/include/net/mana/mana.h
+++ b/include/net/mana/mana.h
@@ -43,7 +43,7 @@ enum TRI_STATE {
  * size beyond this value gets rejected by __alloc_page() call.
  */
 #define MAX_RX_BUFFERS_PER_QUEUE 8192
-#define DEF_RX_BUFFERS_PER_QUEUE 512
+#define DEF_RX_BUFFERS_PER_QUEUE 1024
 #define MIN_RX_BUFFERS_PER_QUEUE 128
 
 /* This max value for TX buffers is derived as the maximum allocatable
-- 
2.43.0