gistfile1.txt

From 25db38a65568d13b5ef070b29dc13bde137d4d6d Mon Sep 17 00:00:00 2001
From: Rosen Penev <[email protected]>
Date: Wed, 27 Jun 2018 17:02:36 -0700
Subject: [PATCH] ag71xx: Reorder ring struct for lower cache thrashing.

Based on Qualcomm's upstream code. Reordered a bit different.

iperf3 speed goes from ~279mbps to ~320mbps on an Archer C7v4.

Signed-off-by: Rosen Penev <[email protected]>
---
 .../drivers/net/ethernet/atheros/ag71xx/ag71xx.h    | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/target/linux/ath79/files/drivers/net/ethernet/atheros/ag71xx/ag71xx.h b/target/linux/ath79/files/drivers/net/ethernet/atheros/ag71xx/ag71xx.h
index 22b22522a3..533fe98170 100644
--- a/target/linux/ath79/files/drivers/net/ethernet/atheros/ag71xx/ag71xx.h
+++ b/target/linux/ath79/files/drivers/net/ethernet/atheros/ag71xx/ag71xx.h
@@ -107,13 +107,16 @@ struct ag71xx_buf {
 };
 
 struct ag71xx_ring {
-	struct ag71xx_buf	*buf;
-	u8			*descs_cpu;
-	dma_addr_t		descs_dma;
-	u16			desc_split;
-	u16			order;
+	/* "Hot" fields in the data path. */
 	unsigned int		curr;
 	unsigned int		dirty;
+
+	/* "Cold" fields - not used in the data path. */
+	struct ag71xx_buf	*buf;
+	u16			order;
+	u16			desc_split;
+	dma_addr_t		descs_dma;
+	u8			*descs_cpu;
 };
 
 struct ag71xx_int_stats {
-- 
2.17.1