openwrt/target/linux/bcm53xx/patches-5.4/600-net-disable-GRO-by-default.patch
Rafał Miłecki c032ed3c26 bcm53xx: disable GRO by default at kernel level
This improves NAT masquarade network performance.

An alternative to kernel change would be runtime setup but that requires
ethtool and identifying relevant network interface and all related
switch ports interfaces.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
(cherry picked from commit 82d0dd8f8a)
2022-07-08 16:18:25 +02:00

33 lines
1.2 KiB
Diff

From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <rafal@milecki.pl>
Date: Mon, 20 Jun 2022 10:01:18 +0200
Subject: [PATCH] net: disable GRO by default
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In many cases GRO improves network performance however it comes at a
cost of chacksums calculations. In case of slow CPU and missing hardware
csum calculation support GRO can actually decrease network speed.
On BCM4708 *disabling* GRO results in following NAT masquarade speed
changes:
1. 364 Mb/s → 396 Mb/s (packet steering disabled)
2. 341 Mb/s → 566 Mb/s (packet steering enabled)
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
---
include/linux/netdev_features.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/include/linux/netdev_features.h
+++ b/include/linux/netdev_features.h
@@ -224,7 +224,7 @@ static inline int find_next_netdev_featu
#define NETIF_F_UPPER_DISABLES NETIF_F_LRO
/* changeable features with no special hardware requirements */
-#define NETIF_F_SOFT_FEATURES (NETIF_F_GSO | NETIF_F_GRO)
+#define NETIF_F_SOFT_FEATURES (NETIF_F_GSO)
#define NETIF_F_VLAN_FEATURES (NETIF_F_HW_VLAN_CTAG_FILTER | \
NETIF_F_HW_VLAN_CTAG_RX | \