From 8b4703e9bd1172a5f8244276ebb94302e6153e26 Mon Sep 17 00:00:00 2001 From: Vlad Yasevich Date: Mon, 3 Mar 2014 15:33:53 -0500 Subject: [PATCH] macvlan: Add support for 'always_on' offload features Macvlan currently inherits all of its features from the lower device. When lower device disables offload support, this causes macvlan to disable offload support as well. This causes performance regression when using macvlan/macvtap in bridge mode. It can be easily demonstrated by creating 2 namespaces using macvlan in bridge mode and running netperf between them: MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 10.0.0.1 () port 0 AF_INET Recv Send Send Socket Socket Message Elapsed Size Size Size Time Throughput bytes bytes bytes secs. 10^6bits/sec 87380 16384 16384 20.00 1204.61 To restore the performance, we add software offload features to the list of "always_on" features for macvlan. This way when a namespace or a guest using macvtap initially sends a packet, this packet will not be segmented at macvlan level. It will only be segmented when macvlan sends the packet to the lower device. MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 10.0.0.1 () port 0 AF_INET Recv Send Send Socket Socket Message Elapsed Size Size Size Time Throughput bytes bytes bytes secs. 10^6bits/sec 87380 16384 16384 20.00 5507.35 Fixes: 6acf54f1cf0a6747bac9fea26f34cfc5a9029523 (macvtap: Add support of packet capture on macvtap device.) Fixes: 797f87f83b60685ff8a13fa0572d2f10393c50d3 (macvlan: fix netdev feature propagation from lower device) CC: Florian Westphal CC: Christian Borntraeger CC: Jason Wang CC: Michael S. Tsirkin Tested-by: Christian Borntraeger Signed-off-by: Vlad Yasevich Signed-off-by: David S. Miller --- drivers/net/macvlan.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c index a5d21893670d..1831fb7cd017 100644 --- a/drivers/net/macvlan.c +++ b/drivers/net/macvlan.c @@ -506,6 +506,9 @@ static int macvlan_change_mtu(struct net_device *dev, int new_mtu) static struct lock_class_key macvlan_netdev_xmit_lock_key; static struct lock_class_key macvlan_netdev_addr_lock_key; +#define ALWAYS_ON_FEATURES \ + (NETIF_F_SG | NETIF_F_GEN_CSUM | NETIF_F_GSO_SOFTWARE | NETIF_F_LLTX) + #define MACVLAN_FEATURES \ (NETIF_F_SG | NETIF_F_ALL_CSUM | NETIF_F_HIGHDMA | NETIF_F_FRAGLIST | \ NETIF_F_GSO | NETIF_F_TSO | NETIF_F_UFO | NETIF_F_GSO_ROBUST | \ @@ -539,7 +542,7 @@ static int macvlan_init(struct net_device *dev) dev->state = (dev->state & ~MACVLAN_STATE_MASK) | (lowerdev->state & MACVLAN_STATE_MASK); dev->features = lowerdev->features & MACVLAN_FEATURES; - dev->features |= NETIF_F_LLTX; + dev->features |= ALWAYS_ON_FEATURES; dev->gso_max_size = lowerdev->gso_max_size; dev->iflink = lowerdev->ifindex; dev->hard_header_len = lowerdev->hard_header_len; @@ -699,7 +702,7 @@ static netdev_features_t macvlan_fix_features(struct net_device *dev, features = netdev_increment_features(vlan->lowerdev->features, features, mask); - features |= NETIF_F_LLTX; + features |= ALWAYS_ON_FEATURES; return features; }