From 66e5133f19e901a044fa5eaeeb6ecff4545839e5 Mon Sep 17 00:00:00 2001
From: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
Date: Mon, 1 Jun 2015 21:55:06 +0900
Subject: [PATCH] vlan: Add GRO support for non hardware accelerated vlan
Currently packets with non-hardware-accelerated vlan cannot be handled
by GRO. This causes low performance for 802.1ad and stacked vlan, as their
vlan tags are currently not stripped by hardware.
This patch adds GRO support for non-hardware-accelerated vlan and
improves receive performance of them.
Test Environment:
vlan device (.1Q) on vlan device (.1ad) on ixgbe (82599)
Result:
- Before
$ netperf -t TCP_STREAM -H 192.168.20.2 -l 60
Recv Send Send
Socket Socket Message Elapsed
Size Size Size Time Throughput
bytes bytes bytes secs. 10^6bits/sec
87380 16384 16384 60.00 5233.17
Rx side CPU usage:
%usr %sys %irq %soft %idle
0.27 58.03 0.00 41.70 0.00
- After
$ netperf -t TCP_STREAM -H 192.168.20.2 -l 60
Recv Send Send
Socket Socket Message Elapsed
Size Size Size Time Throughput
bytes bytes bytes secs. 10^6bits/sec
87380 16384 16384 60.00 7586.85
Rx side CPU usage:
%usr %sys %irq %soft %idle
0.50 25.83 0.00 59.53 14.14
[ Register VLAN offloads with priority 10 -DaveM ]
Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
include/linux/if_vlan.h | 20 +++++++++
net/8021q/vlan.c | 96 +++++++++++++++++++++++++++++++++++++++++
2 files changed, 116 insertions(+)
diff --git a/include/linux/if_vlan.h b/include/linux/if_vlan.h
index a40d29846ac2..67ce5bd3b56a 100644
--- a/include/linux/if_vlan.h
+++ b/include/linux/if_vlan.h
@@ -628,4 +628,24 @@ static inline netdev_features_t vlan_features_check(const struct sk_buff *skb,
return features;
}
+/**
+ * compare_vlan_header - Compare two vlan headers
+ * @h1: Pointer to vlan header
+ * @h2: Pointer to vlan header
+ *
+ * Compare two vlan headers, returns 0 if equal.
+ *
+ * Please note that alignment of h1 & h2 are only guaranteed to be 16 bits.
+ */
+static inline unsigned long compare_vlan_header(const struct vlan_hdr *h1,
+ const struct vlan_hdr *h2)
+{
+#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
+ return *(u32 *)h1 ^ *(u32 *)h2;
+#else
+ return ((__force u32)h1->h_vlan_TCI ^ (__force u32)h2->h_vlan_TCI) |
+ ((__force u32)h1->h_vlan_encapsulated_proto ^
+ (__force u32)h2->h_vlan_encapsulated_proto);
+#endif
+}
#endif /* !(_LINUX_IF_VLAN_H_) */
diff --git a/net/8021q/vlan.c b/net/8021q/vlan.c
index 59555f0f8fc8..d2cd9de4b724 100644
--- a/net/8021q/vlan.c
+++ b/net/8021q/vlan.c
@@ -618,6 +618,92 @@ static int vlan_ioctl_handler(struct net *net, void __user *arg)
return err;
}
+static struct sk_buff **vlan_gro_receive(struct sk_buff **head,
+ struct sk_buff *skb)
+{
+ struct sk_buff *p, **pp = NULL;
+ struct vlan_hdr *vhdr;
+ unsigned int hlen, off_vlan;
+ const struct packet_offload *ptype;
+ __be16 type;
+ int flush = 1;
+
+ off_vlan = skb_gro_offset(skb);
+ hlen = off_vlan + sizeof(*vhdr);
+ vhdr = skb_gro_header_fast(skb, off_vlan);
+ if (skb_gro_header_hard(skb, hlen)) {
+ vhdr = skb_gro_header_slow(skb, hlen, off_vlan);
+ if (unlikely(!vhdr))
+ goto out;
+ }
+
+ type = vhdr->h_vlan_encapsulated_proto;
+
+ rcu_read_lock();
+ ptype = gro_find_receive_by_type(type);
+ if (!ptype)
+ goto out_unlock;
+
+ flush = 0;
+
+ for (p = *head; p; p = p->next) {
+ struct vlan_hdr *vhdr2;
+
+ if (!NAPI_GRO_CB(p)->same_flow)
+ continue;
+
+ vhdr2 = (struct vlan_hdr *)(p->data + off_vlan);
+ if (compare_vlan_header(vhdr, vhdr2))
+ NAPI_GRO_CB(p)->same_flow = 0;
+ }
+
+ skb_gro_pull(skb, sizeof(*vhdr));
+ skb_gro_postpull_rcsum(skb, vhdr, sizeof(*vhdr));
+ pp = ptype->callbacks.gro_receive(head, skb);
+
+out_unlock:
+ rcu_read_unlock();
+out:
+ NAPI_GRO_CB(skb)->flush |= flush;
+
+ return pp;
+}
+
+static int vlan_gro_complete(struct sk_buff *skb, int nhoff)
+{
+ struct vlan_hdr *vhdr = (struct vlan_hdr *)(skb->data + nhoff);
+ __be16 type = vhdr->h_vlan_encapsulated_proto;
+ struct packet_offload *ptype;
+ int err = -ENOENT;
+
+ rcu_read_lock();
+ ptype = gro_find_complete_by_type(type);
+ if (ptype)
+ err = ptype->callbacks.gro_complete(skb, nhoff + sizeof(*vhdr));
+
+ rcu_read_unlock();
+ return err;
+}
+
+static struct packet_offload vlan_packet_offloads[] __read_mostly = {
+ {
+ .type = cpu_to_be16(ETH_P_8021Q),
+ .priority = 10,
+ .callbacks = {
+ .gro_receive = vlan_gro_receive,
+ .gro_complete = vlan_gro_complete,
+ },
+ },
+ {
+ .type = cpu_to_be16(ETH_P_8021AD),
+ .priority = 10,
+ .callbacks = {
+ .gro_receive = vlan_gro_receive,
+ .gro_complete = vlan_gro_complete,
+ },
+ },
+};
+
static int __net_init vlan_init_net(struct net *net)
{
struct vlan_net *vn = net_generic(net, vlan_net_id);
@@ -645,6 +731,7 @@ static struct pernet_operations vlan_net_ops = {
static int __init vlan_proto_init(void)
{
int err;
+ unsigned int i;
pr_info("%s v%s\n", vlan_fullname, vlan_version);
@@ -668,6 +755,9 @@ static int __init vlan_proto_init(void)
if (err < 0)
goto err5;
+ for (i = 0; i < ARRAY_SIZE(vlan_packet_offloads); i++)
+ dev_add_offload(&vlan_packet_offloads[i]);
+
vlan_ioctl_set(vlan_ioctl_handler);
return 0;
@@ -685,7 +775,13 @@ static int __init vlan_proto_init(void)
static void __exit vlan_cleanup_module(void)
{
+ unsigned int i;
+
vlan_ioctl_set(NULL);
+
+ for (i = 0; i < ARRAY_SIZE(vlan_packet_offloads); i++)
+ dev_remove_offload(&vlan_packet_offloads[i]);
+
vlan_netlink_fini();
unregister_netdevice_notifier(&vlan_notifier_block);
--
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