From 37b0ea8fef56ccc29bd5a07f235ac218f7f98379 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 22 Jan 2026 19:03:49 +0000 Subject: net: expand NETDEV_RSS_KEY_LEN to 256 bytes NETDEV_RSS_KEY_LEN has been set to 52 bytes in 2014, until now. Jakub suggested we bump the size to 128 bytes or more. Some drivers (like idpf) were already working around the core limit. Since this change might cause some issues in admin scripts, bump it directly to 256 in one go. tjbp26:~# cat /proc/sys/net/core/netdev_rss_key | wc -c 768 tjbp26:~# ethtool -x eth1 RX flow hash indirection table for eth1 with 32 RX ring(s): ... RSS hash key: fe:16:5b:2f:93:85:c2:c9:c1:ef:bd:60:c6:e0:2b:99:4d:bf:b7:14:c8:1e:8d:cb:31:17:51:da:55:eb:91:d9:9e:f9:89:9b:44:a1:dc:08:72:3a:b3:d6:31:86:9a:fe:02:3a:0d:eb:a1:7c:f5:a3:51:3b:08:56:c9:3f:71:69:01:ba:70:38 RSS hash function: toeplitz: on xor: off crc32: off Suggested-by: Jakub Kicinski Link: https://lore.kernel.org/netdev/20260122075206.504ec591@kernel.org/ Signed-off-by: Eric Dumazet Reviewed-by: Willem de Bruijn Link: https://patch.msgid.link/20260122190349.2771064-1-edumazet@google.com Signed-off-by: Jakub Kicinski --- include/linux/netdevice.h | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 179b50f98cee..d4e6e00bb90a 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -5166,8 +5166,7 @@ void *netdev_lower_dev_get_private(struct net_device *dev, void netdev_lower_state_changed(struct net_device *lower_dev, void *lower_state_info); -/* RSS keys are 40 or 52 bytes long */ -#define NETDEV_RSS_KEY_LEN 52 +#define NETDEV_RSS_KEY_LEN 256 extern u8 netdev_rss_key[NETDEV_RSS_KEY_LEN] __read_mostly; void netdev_rss_key_fill(void *buffer, size_t len); -- cgit v1.2.3