The patch below does not apply to the 4.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 2d19c3fd80178160dd505ccd7fed1643831227a5 Mon Sep 17 00:00:00 2001 From: Robert Hancock robert.hancock@calian.com Date: Tue, 18 Jan 2022 15:41:32 -0600 Subject: [PATCH] net: axienet: increase default TX ring size to 128
With previous changes to make the driver handle the TX ring size more correctly, the default TX ring size of 64 appears to significantly bottleneck TX performance to around 600 Mbps on a 1 Gbps link on ZynqMP. Increasing this to 128 seems to bring performance up to near line rate and shouldn't cause excess bufferbloat (this driver doesn't yet support modern byte-based queue management).
Fixes: 8a3b7a252dca9 ("drivers/net/ethernet/xilinx: added Xilinx AXI Ethernet driver") Signed-off-by: Robert Hancock robert.hancock@calian.com Signed-off-by: David S. Miller davem@davemloft.net
diff --git a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c index b4f42ee9b75d..377c94ec2486 100644 --- a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c +++ b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c @@ -41,7 +41,7 @@ #include "xilinx_axienet.h"
/* Descriptors defines for Tx and Rx DMA */ -#define TX_BD_NUM_DEFAULT 64 +#define TX_BD_NUM_DEFAULT 128 #define RX_BD_NUM_DEFAULT 1024 #define TX_BD_NUM_MIN (MAX_SKB_FRAGS + 1) #define TX_BD_NUM_MAX 4096