target/linux/bcm53xx/patches-5.15/600-net-disable-GRO-by-default.patch

   1 From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <rafal@milecki.pl>
   2 Date: Mon, 20 Jun 2022 10:01:18 +0200
   3 Subject: [PATCH] net: disable GRO by default
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   7
   8 In many cases GRO improves network performance however it comes at a
   9 cost of chacksums calculations. In case of slow CPU and missing hardware
  10 csum calculation support GRO can actually decrease network speed.
  11
  12 On BCM4708 *disabling* GRO results in following NAT masquarade speed
  13 changes:
  14 1. 364 Mb/s → 396 Mb/s (packet steering disabled)
  15 2. 341 Mb/s → 566 Mb/s (packet steering enabled)
  16
  17 Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
  18 ---
  19  include/linux/netdev_features.h | 4 ++--
  20  1 file changed, 2 insertions(+), 2 deletions(-)
  21
  22 --- a/include/linux/netdev_features.h
  23 +++ b/include/linux/netdev_features.h
  24 @@ -242,10 +242,10 @@ static inline int find_next_netdev_featu
  25  #define NETIF_F_UPPER_DISABLES NETIF_F_LRO
  26
  27  /* changeable features with no special hardware requirements */
  28 -#define NETIF_F_SOFT_FEATURES  (NETIF_F_GSO | NETIF_F_GRO)
  29 +#define NETIF_F_SOFT_FEATURES  (NETIF_F_GSO)
  30
  31  /* Changeable features with no special hardware requirements that defaults to off. */
  32 -#define NETIF_F_SOFT_FEATURES_OFF      (NETIF_F_GRO_FRAGLIST | NETIF_F_GRO_UDP_FWD)
  33 +#define NETIF_F_SOFT_FEATURES_OFF      (NETIF_F_GRO_FRAGLIST | NETIF_F_GRO_UDP_FWD | NETIF_F_GRO)
  34
  35  #define NETIF_F_VLAN_FEATURES  (NETIF_F_HW_VLAN_CTAG_FILTER | \
  36                                  NETIF_F_HW_VLAN_CTAG_RX | \