From: Jason Wang <jasowang@redhat.com>
Date: Wed, 14 Mar 2018 11:23:40 +0800
Subject: tuntap: XDP_TX can use native XDP
Patch-mainline: v4.17-rc1
Git-commit: 59655a5b6c837e392e873629591069c898585592
References: bsc#1109837
Now we have ndo_xdp_xmit, switch to use it instead of the slow generic
XDP TX routine. XDP_TX on TAP gets ~20% improvements from ~1.5Mpps to
~1.8Mpps on 2.60GHz Core(TM) i7-5600U.
Signed-off-by: Jason Wang <jasowang@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
drivers/net/tun.c | 19 ++++++++-----------
1 file changed, 8 insertions(+), 11 deletions(-)
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -1611,7 +1611,6 @@ static struct sk_buff *tun_build_skb(str
unsigned int delta = 0;
char *buf;
size_t copied;
- bool xdp_xmit = false;
int err, pad = TUN_RX_PAD;
rcu_read_lock();
@@ -1669,8 +1668,14 @@ static struct sk_buff *tun_build_skb(str
preempt_enable();
return NULL;
case XDP_TX:
- xdp_xmit = true;
- /* fall through */
+ get_page(alloc_frag->page);
+ alloc_frag->offset += buflen;
+ if (tun_xdp_xmit(tun->dev, &xdp))
+ goto err_redirect;
+ tun_xdp_flush(tun->dev);
+ rcu_read_unlock();
+ preempt_enable();
+ return NULL;
case XDP_PASS:
delta = orig_data - xdp.data;
break;
@@ -1697,14 +1702,6 @@ static struct sk_buff *tun_build_skb(str
get_page(alloc_frag->page);
alloc_frag->offset += buflen;
- if (xdp_xmit) {
- skb->dev = tun->dev;
- generic_xdp_tx(skb, xdp_prog);
- rcu_read_unlock();
- preempt_enable();
- return NULL;
- }
-
rcu_read_unlock();
preempt_enable();